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EIS31September 2011

JOUrNAL OF tHe eNGINeerINGINteGrItY SOCIetY

ENGINEERING INTEGRITY

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the telescopic Cantilever beam: part 2 - Stress Analysis•

eIS website: www.e-i-s.org.uk

EIS 31 Covers v01.indd 1 22/9/11 14:13:10

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INSTRUMENTATION, ANALYSIS & TESTING EXHIBITION

THE SILVERSTONE WING, SILVERSTONE RACE TRACK, TUESDAY 6th MARCH 2012, 10.00-16.00.

Engineering Integrity Society

The 2012 EIS exhibition is being held in the recently opened international exhibition centre at Silverstone, which provides superb new visitor and exhibitor facilities. Entrance to the exhibition and all technical activities are free. There will be complementary refreshments for visitors.

,

ExhibitionThere will be 50 exhibitors presenting the latest advances in technology in, aerospace, automotive, motor-sport, rail, power generation, and medical industries. Visitors will be able to discuss these developments, and their applications, with exhibitors in an informal atmosphere.

Technical ActivitiesThere will be open forums held during the day including:

- Kinetic Energy Recovery Systems (KERS) - CAE Predictions vs Physical Testing - Vision and Lasers Systems - Application of Electric Actuators

Guest panels comprising experts from industry will expand on the technical developments andtake questions from the floor.There will be workshops in signal processing together with selective technical presentations.

ExhibitorsIf you are interested in exhibiting please contact the EIS Secretariat.

VisitorsIf you are interested in attending please pre-register for the event which will ensure you reserve a place at the technical events.

For further information, or to pre-register please contact the EIS at: exhibition@e-i-s.org.uk, or visit the EIS website at www.e-i-s.org.uk

EIS 31 Inners v01.indd 1 22/9/11 15:47:08

INDEX TO ADVERTISEMENTS

Amber Instruments ................................................... 40

Bruel & Kjaer ............................................... Back cover

CPD Dynamics ......................................................... 40

Data Physics ..................................... Inside front cover

Ixthus Instrumentation ..................... Inside back cover

Kemo ........................................................................ 40

M+P International .............................. Inside back cover

Micro Movements ........................................................ 2

Team Corporation ...................................................... 2

Techni Measure .......................................................... 2

EIS 31 Inners v01.indd 2 22/9/11 15:47:10

ContentsInstrumentation, Analysis & Testing Exhibition 2012 .......................................................................................................... 1

Index to Advertisements ...................................................................................................................................................... 2

Editorial ................................................................................................................................................................................ 5

Technical Paper: The Telescopic Cantilever Beam: Part 2 – Stress Analysis .................................................................. 6

Technical Article: Mechanical Testing of Micro Specimens and Semi-finished Micro Products ..................................... 18

Report on EIS Forum “Seven posters - is that three too many?” ..................................................................................... 23

Corporate Sponsor Application Form ................................................................................................................................ 23

Industry News ....................................................................................................................................................................24

Product News ....................................................................................................................................................................28

Personal Membership Application Form .......................................................................................................................... 30

Profiles of Company Members ......................................................................................................................................... 31

News on Smart Materials and Structures ......................................................................................................................... 32

News from Formula Student ............................................................................................................................................. 33

Diary of Event .....................................................................................................................................................................33

Challenge to Improve the Process from design to product ............................................................................................. 34

News from British Standards ............................................................................................................................................ 35

“Open Access”, another instalment .................................................................................................................................. 36

Group News ......................................................................................................................................................................37

Committee Members ........................................................................................................................................................38

Sponsor Companies ......................................................................................................................................................... 39

Front Cover: Courtesy of Institution of Mechanical Engineers

FORUM FOR APPLIED MECHANICS (FAM)

The EIS is a sponsor member of the Forum for Applied Mechanics (FAM), which provides an interaction between a

number of organisations in the UK where there is an interest in applied mechanics, both experimental and theoretical.

Current sponsor members of FAM are the EIS, NAFEMS, IMechE, BSSM, IoP and the BGA (British Gear Association).

The FAM website contains details of events being held by the sponsor members, together with a direct link to the

sponsor members’ websites. Some of these events may be of interest to you or your colleagues. Access to the FAM

website can be gained either directly www.appliedmechanics.org or via the EIS website ‘Links’ page.

3EIS 31 Inners v01.indd 3 22/9/11 15:47:10

HONORARY EDITOR:

Dr Karen Perkins

MANAGING EDITOR:

Mrs Catherine Pinder

Anchor House, Mill Road,

Stokesby, Great Yarmouth, NR29 3EY

Tel. 07979 270998

E-mail: catherine@cpinder.com

EDITORIAL BOARD:

Paul Armstrong

Brian Griffiths

Dr Fabrizio Scarpa

Norman Thornton

EIS Secretariat:

Engineering Integrity Society

18 Oak Close, Bedworth,

Warwickshire, CV12 9AJ

Tel & Fax: +44 (0)2476 730126

E-mail: eis@e-i-s.org.uk

WWW: http://www.e-i-s.org.uk

EDITORIAL POLICY:

Engineering Integrity contains various items of

information of interest to, or directly generated by, the

Engineering Integrity Society. The items of information

can be approximately subdivided into three general

categories: technical papers, topical discussion

pieces and news items. The items labelled in the

journal as technical papers are peer reviewed by

a minimum of two reviewers in the normal manner of

academic journals, following a standard protocol.

The items of information labelled as topical

discussions and the news items have been reviewed

by the journal editorial staff and found to conform

to the legal and professional standards of the

Engineering Integrity Society.

COPYRIGHT

Copyright of the technical papers included in this issue

is held by the Engineering Integrity Society unless

otherwise stated.

Photographic contributions for the front cover

are welcomed.

ISSN 1365-4101/2011

The Engineering Integrity Society (EIS)

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PRINCIPAL ACTIVITY OF THE

ENGINEERING INTEGRITY SOCIETY

The principal activity of the Engineering Integrity Society, is

the arrangement of conferences, seminars, exhibitions and

workshops to advance the education of persons working

in the field of engineering. This is achieved by providing a

forum for the interchange of ideas and information on

engineering practice. The Society is particularly committed

to promoting projects which support professional

development and attract young people into the profession.

‘Engineering Integrity’, the Journal of the Engineering

Integrity Society is published twice a year.

EIS 31 Inners v01.indd 4 22/9/11 15:47:11

Editorial

5

Welcome to the 31st edition of the EIS

journal. With hurricanes blowing away

the last vestiges of summer we have a

bumper edition for you, containing two

papers and an extended range of news

sections, including the new ‘product

news’ giving industry the opportunity to

announce key technology releases.

The first paper, ‘the telescopic cantilever beam: Part 2’

describes the stress analysis performed for a telescopic

cantilever beam and follows from Part I published in the

last edition. The second paper, ‘Mechanical testing of

micro specimens and semi finished micro products’

provides user experience of test frame design specifically

for the purpose of small scale testing. Something close

to our interests at Swansea, we are often asked to assess

a new material capability based on minimal material

avai labi l i ty before a ful l scale melt is produced.

Development of new al loys often starts with the

manufacture of small buttons of experimental alloy and

a preliminary mechanical assessment is required from

a quantity of material more commonly utilized for a single

mechanical test. The development of tests techniques

for gaining a range of mechanical properties from

minimal material represents a technological challenge.

Smart materials also hit on a pertinent point with regards

to new exotic materials. Many advanced alloys nowadays

consist of the rare earth elements that offer improvements

in temperature and mechanical capabi l i ty. Future

availability and access to these elements is paramount

and forms a key part of new alloy development.

The Industry news section again provides an interesting

mix of topics with a range of green issues, robotics

featuring in several guises and the application of phase-

change materials in the development of ‘brain-like’

computers. Perhaps these computers will develop more

understanding than the two chatbots who made the

national news recently when their conversation rapidly

descended into an argument.

Despite our perennial concerns about the shortage of

engineering graduates, recent research from

Birmingham University suggests that many engineering

graduates are joining their psychology colleagues

behind the counters of fast food restaurants. The authors

of the study note the contrast between their findings and

the experience of employers in the sector, suggesting

that the shortage is really one of quality STEM graduates.

Perhaps the private sector has yet to accept that education

standards are constantly improving!

With the new University tuition fee regime starting next

year this has been a bumper year for recruitment in many

institutions. The past couple of years of ‘plenty’ have

allowed entry requirements to be raised, but whether or

not the actual quality of the intake has improved remains

to be seen. The over emphasis on rote learning at A-

level leaves many students, not just the weaker ones,

struggling to genuinely understand material, let alone

analyse a problem they haven’t been given a model

answer for. In the new market lead system the student

will be king and University administrators will be straining

every sinew to improve their student satisfaction ratings.

In this environment it is a brave or foolish lecturer who

denies the customer the spoon feeding they crave. At

least employabi l i ty wi l l a lso be a headl ine key

performance indicator.

Finally, the group events are proving extremely popular;

with attendance at a record high. It is encouraging to see

that many attendees were from the young engineers keen

to advertise their work.

Karen Perkins

Honorary Editor

EIS 31 Inners v01.indd 5 22/9/11 15:47:11

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17. ISSN 1365-4101/2011

Technical Paper

The Telescopic Cantilever Beam: Part 2 – Stress AnalysisJ. Abraham, D. W. A. Rees and S. Sivaloganathan, School of Engineering and Design, Brunel University, Uxbridge, Middlesex,

UB8 3PH

Abstract

This paper is an extension to a Part 1 analysis of the

deflection for a telescopic cantilever beam [1]. The Tip

Reaction Model, proposed in that paper, establishes

reactions at the tips of the overlapping portions as the

mechanism of transfer of the external loads between

sections of the telescopic beam. In Part 1 a three-section

telescopic beam was analysed for deflection using these

forces within a repeated integration method. In Part 2 the

bending and shear stresses for the three-section cantilever,

are obtained both analytically and numerically. A check upon

stress levels is provided from a parallel study upon an

equivalent, two-stepped, continuous beam. Graphical

presentations of the beam stresses, found from applying

the two methods to each structure, are self-validating. That

is, the continuous beam theory provides a check upon

numerical stress levels from FEA and, in turn, FEA provides

a check upon the analytical stresses calculated from tip

reactions within a telescopic beam. The fact that

comparable stress levels were found confirms that the

analytical technique proposed is perfectly adequate for a

telescoping beam, just as the classical theory is adequate

for continuous beams. Taken together, Parts 1 and 2 provide

an analytical theory for bending of a discontinuous beam

that did not exist heretofore, thereby obviating the need for a

numerical solution.

1.0 Introduction

Continuous structures balance the application of external

loads with an internal resistance within their material which

is commonly called stress. For a beam in particular, resisting

moments arise from its internal stress to oppose the

bending moments that the transverse loading produces.

For example, consider the simply-supported beam with self-

weight w/unit length subjected to four concentrated loads

W1 ... W

4 shown in Figure 1.

Figure 1: Moment of resistance within section at x-position

To understand how the material in the beam resists the

external loads it is seen that the beam sags beneath the

applied loads. Sagging creates a compressive stress within

longitudinal fibres lying in the upper half of the section and

tensile stress within fibres in the bottom half. A neutral

(unstressed) plane MN divides each half as shown in Figure

1. The equivalent compressive force acting on the upper

area MEFN is given by ‘C’. Similarly the equivalent tensile

force acting on the lower area MHGN is given by ‘T’. The

external loads applied and the effective shear force S acting

on the plane EFGH are assumed to be concentrated on the

vertical plane of symmetry, as shown. The forces that act

over length AX of the beam are therefore: (a) a vertical reaction

RA at A, (b) external concentrated loads W

1and W

2, (c)

uniformly distributed load w acting over the length x , (d)

shear force S offered by section EFGH, (d) a compressive

resistance C and (e) a tensile resistance T. The magnitudes

of the forces C and T are equal and, since they act in

opposing directions, separated by a distance d, they form

the section’s moment of resistance:

MR = Cd = Td (1)

Taking moments about O gives the bending moment due to

the external forces

(2)

In continuous beams we may equate (1) and (2) when

applying the principle that the moment at a given section

due to externally applied loads equals the moment of

resistance at that section. However, the same principle

cannot be applied to telescopic beams within the

discontinuous region between overlapping sections,

especially where there is a sizeable gap between them. To

overcome this the authors proposed [1] their Tip Reaction

Model, the principle of which is summarised in the following

section.

1.1 Tip Reactions

The tip reaction model assumes that in a telescopic

cantilever beam the overlapping ends have concentrated

reactions that transmit the effects of the loads applied to the

top surface of the cantilever assembly. Consider the three-

section beam assembly shown in Figure 2. The fixed beam

AB has an overlap of length CB with beam CD. The outer

beam EF also has an overlap of length ED with beam CD.

Tip reactions exist at the contact points C and B between

6EIS 31 Inners v01.indd 6 22/9/11 15:47:12

beams AB and CD. Similarly, tip reactions exist at the

overlapping ends E and D between beams CD and EF. In

addition, Fig. 3a shows the external loading applied to the

assembly which is a combination of self-weight and a

concentrated end-load. Thus, each of the three-sections

bears the loading shown in Figures 3b-d.

Figure 2: Telescopic beam assembly with three sections

Figure 3: Telescopic assembly showing tip reactions

within individual beams

In Figs 3b-d each beam section is shown separately as a

free-body diagram. Within each diagram the tip reactions

are the forces applied to each section from its neighbour.

Thus, the end-section exerts upon the middle section a

downward force at D and an upward force at E (see Fig. 3c).

The middle-section exerts equal forces upon the end-

section at D and E but in opposition to these (see Fig. 3d).

That the tip reactions must remain in equilibrium with the

applied loading enables these reactions to be found [1].

Consequently, the internal shear force and moment within

each length may be calculated from the reactions instead of

the moment of resistance used normally for a continuous

beam. The shear force and bending moment variations

along each length are converted to their respective stresses

in the following section. The stress magnitudes are

compared with those obtained from a finite element analysis.

The analyses were carried out on a telescopic cantilever

assembly consisting of three hollow sections the details of

which follow. Comparable stress levels were anticipated

from a further validation which compares magnitudes

between the ‘moment of resistance’ theory and FEA for a

continuous stepped-beam of similar dimensions and

loading.

1.2 Bending Stress

The longitudinal bending stress in a beam is calculated

from the bending moment M by a standard expression [2]:

y

I

M=σ (3)

where I is second moment of area of the beam section and

y is the distance from the neutral axis at which this stress

applies. Consider the beam assembly shown in Figure 2

and assume that it is fixed at end A and carries a tip load at

F. Due to self-weight and the tip loading applied there will

be tensile stresses in all three beam sections above the

horizontal of symmetry (neutral plane) and compressive

stresses below the plane of symmetry. For each section

depth:1d ,

2d and 3d , the beam is represented by the

vertical plane of symmetry upon which the maximum bending

stress occurs at their top surfaces. These are found from

Eq. (3) as:

1

1

12I

dM ×=σ ,

2

2

22I

dM ×=σ and

3

3

32I

dM ×=σ

(4a-c)

The d- and I-values are referred to a chosen geometry given in

the following section. The bending moment M in Eqs 4a-c

varies within the length in a manner provided by an M-diagram

constructed from the applied loading and the tip reactions.

1.3 Shear Stress

Figure 4: Shear stress parameters at depth position y1 for

section x-x

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

7EIS 31 Inners v01.indd 7 22/9/11 15:47:12

Consider the uniform cantilever shown in Figure 4. Let a

transverse shear force S apply vertically along the section

X-X at a distance x from the fixed-end. It is required to find

the shear stress within section X-X at a distance y1 (at EF)

from the neutral axis as shown. The area above EF is a and

the distance from the centroid of this area to the neutral axis

is . Given a uniform breadth b for the cross-section, the

transverse shear stress at the required position is found

from [2]:

(5)

Equations (3) - (5) may be applied to both telescopic and

continuous beams when M and S are known. In what follows

M and S are converted to their respective stress distributions

from within the diagrams that show the variations in M and

S over the length. The method of constructing S- and M-

diagrams for continuous cantilever beams, carrying

combined concentrated and distributed loading, can be

found in many texts [2-5]. The F- and M-diagrams for a

telescopic beam may be constructed separately once the

tip reactions for each of Figs 3b-d are known (see Part 1 [1])

and then superimposed to find their net values within the

overlaps.

2.0 Case Study Formulation

The following three investigations have been made

i. To calculate the bending and shear stresses from the

tip reactions in a telescopic cantilever and compare

these with the results of a Finite Element Analysis

(ABAQUS).

ii. To calculate the bending and shear stresses for a

comparable, single-stepped cantilever and compare

these with a Finite Element Analysis.

iii. To compare the stresses between the telescopic and

continuous cantilevers as provided by the analyses in

(i) and (ii).

Note that for (i) – (iii), the continuous cantilever, being a

simpler structure to solve, offers greater certainty that

realistic, agreeable stress levels will be provided by each

technique.

2.1 Model Geometry

The model telescopic cantilever beam assembly consists

of three hollow square steel sections, each 1 mm thick,

with outer dimensions: 25mm x 25 mm x 1000 mm,

22 mm x 22 mm x 1200 mm and 19 mm x 19 mm x 1200 mm.

A load of 30 N is applied at the end of the beam assembly.

Beam CD and AB have an overlap of 400 mm and beams

CD and EF have an overlap of 300 mm. The second moment

of area about the neutral axis for the cross-section of beams

AB, CD and EF are 9232 mm4 6188 mm4 and 3900 mm4

respectively. Their linear densities (distributed self-weights)

are 0.007536 N/mm 0.006594 N/mm and 0.005652 N/mm

respectively.

2.2 Area Properties

Consider the hollow, square rectangular section shown in

Figure 5. The outer side depth is d and thickness is t for

which the following relationships apply

Figure 5: Hollow, square tubular section

Cross sectional area:

A = (d 2 - (d - 2t)2) = 4t(d - t)mm2

Volume of a section, 1 mm long:

V / L = A = 4t(d - t) = 4t(d - t)mm3 / mm

Self-weight (density) of 1mm3 of steel (taking g = 10 m/s2)

Self-weights of 1 mm long beam sections (distributed loads)

35)1085.7(

−−× Nmm mmNtdt /10)(14.3

4−×−=

(4)

Second moments of area for a hollow square section

( )12

)2(44 tdd

I−−

= (5)

Equations (4) and (5) provide the I- and w -values for the

section dimensions d and t given in Table 1.

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

8

y

EIS 31 Inners v01.indd 8 22/9/11 15:47:13

×

Figure 6: Telescope beam assembly for FEA

3.1 Telescopic Beam Assembly for

FEA

In practice, telescopic beam sections

slide upon and react their loading

through these wear pads. Hence, four

wear pads are introduced to make the

FE analysis correspond with the

analytical approach. Wear pad 1, of 0.5

mm thickness and 5 mm wide, is glued

the inside of the free-end of beam 1 as

shown in Figure 6. Similarly, wear pad

2, of similar dimension, is glued to the

outside end of beam 2. Wear pad 3 is

glued to the inner end of beam 2 and

wear pad 4 is glued to outside end of

beam 3, as shown.

3.2 Finite Element Analysis for the

Assembly

With the details of the telescopic beam

assembly model provided in 3.1, Table

2 shows the finite element analysis

procedure adopted by ABAQUS. The

left-hand side shows the flow chart and

the right-hand side gives the detail.

3.3 Finite Element Analysis of Single-

Stepped Beam

Normally telescopic beam sections

have a 1mm gap between sections to

facilitate easy sliding. This clearance

needs to be allowed for within an

equivalent, continuous stepped-

cantilever. In Fig. 7, the end view 1

shows sections built up from the inner-

section, which results in the outer-

3.0 Finite Element Analyses

Two separate finite element analyses were conducted.

The first applies to the assembled telescopic cantilever

carrying a tip load of 30 N. The second applies to the

single, stepped cantilever with comparable section

dimensions under a similar load.

Table 1: Tubular square-section properties

Table 2: FEA (ABAQUS) for the telescopic beam assembly

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

9EIS 31 Inners v01.indd 9 22/9/11 15:47:13

section having a smaller dimension: 23mm × 23mm having

retained a 1 mm wall thickness. For the present analysis,

the stepped section is reduced down from the outer-section,

so that the resulting inner-section will have the larger

dimension: i.e., 19mm × 19mm for the end-view 2 in Fig. 7.

Referring to Fig. 8, the maximum bending tensile stress

for the assembly occurs along the top surface. The

maximum shear stress occurs along the neutral plane.

These maxima are used as the comparative measure for a

scaled-down model under a tip load of 30 N.

Figure 7: Equivalent continuous stepped-beam (third

angle projection)

3.4 Finite Element Analysis of

the Continuous Cantilever

Details of the continuous

stepped-beam, provided in

section 3.3, were submitted to

ABAQUS for FEA. Table 3 shows

the FE procedure as a flow chart

with detailed explanations given

on the right-hand side.

4.0 Stress Analyses for the

Telescopic Cantilever

The maximum bending stress

comparison between the two

techniques refers to the mid-

width position at the top surface.

This follows the line

A1C

1B

1E

1D

1F

1between sections

in Fig. 8. The maximum shear

stress comparison refers to the

mid-thickness of the walls lying

upon the neutral plane. This

follows the line A2C

2B

2E

2D

2F

2 for

one wall in Fig. 8.

4.1 Force and Moment

Diagrams

A sample of the shear force and

bending moment calculations

required for one of the individual

Table 3: FEA for the continuous beam

Figure 8: Sectional view of the continuous stepped-beam

sections is outlined in Appendices A1-A3. Firstly, in A1, the

tip reactions are calculated from the formulae given in Part 1

[1]. In A2 the shear forces and moments are calculated from

the tip reactions and the applied loading for the beam ACB.

The resulting S- and M-diagrams appear beneath this

separated beam in Fig. 9. In A3 the bending and shear

stresses are calculated from applying Eqs 1-3 to the required

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

10EIS 31 Inners v01.indd 10 22/9/11 15:47:14

positions in this beam’s section. Because of the reduced

scale in the model, units of N and mm are used throughout

in all these calculations. Similar calculations apply to the

remaining beams for which full details have been given

elsewhere [1]

Figure 9: Shear force (N) and bending moment (Nmm)

diagrams for each beam

4.2 Bending Stress Distributions

Figure 10 compares the bending stress distributions

obtained analytically and numerically (thin and thick lines

respectively). The unreinforced beam lengths AB, CD and

EF are shown for which the stress axis refers to the

maximum bending stress at their mid, outer surfaces.

These stress values were obtained at 50 mm intervals along

the top of the beam sections, as shown in Appendix A.3.

FEA values of bending stress were obtained in the manner

outlined in Table 2. The stress dips from FEA at lengths of

600 mm and 1500 mm can be explained by the presence of

wear pads; they decrease the stress concentration in the

overlap area between sections. Before and beyond each

overlap the bending stress in each is seen to diminish from

its greatest value at the fixed-end to zero at the free-end.

Figure 10 shows that there are four further ‘free-ends’ within

this telescopic assembly where the bending stresses are

also zero. However, the surface bending stress in the

connecting tube is not zero at these positions. Here the

reinforcement of the section area from within the overlap

plays no part in the stress reduction, lying at the ends of the

linear regions for beams AB, CD and EF, as shown. The

reduction in stress across these regions is due entirely to

the manner in which the bending moment diminishes with

length. Within each overlap, away from its free-ends, the

area reinforcement becomes effective, serving to equalise

stress at the mid-position, as shown. It will be seen that

this bending stress distribution has its greatest variation

across the overlap compared to equivalent portion of the

continuous stepped-beam. The greatest bending stress

magnitude of 146 MPa in this figure shows that the structure

would remain elastic, given a yield stress for a medium

carbon steel of, say, 400 MPa. Their ratio, which provides

safety factor approaching 3, would be regarded as an

adequate figure for a practical design but a lower factor might

be applied to achieve a weight reduction. Here we should

note that the minimum safety factor is based upon the

greatest stress which applies to the fixed-end only. A fully

optimised cantilever design would employ tapered

contoured beams as a means of maintaining a uniform

safety factor throughout its length [5]. Figure 10 reveals that

a similar, optimal design criterion may be applied to

telescopic structure.

4.3 Shear Stress Distributions for a Telescopic Cantilever

Figure 11 shows the graphical comparison between the

shear stresses obtained analytically with those from FEA

(thin and thick lines respectively). Shear stress values apply

to the mid-wall position upon the neutral plane, where they

take their maximum value [2]. Analytical shear stress values

were obtained at 50 mm length intervals within the neutral

plane, as shown in Appendix A3. FEA values of shear stress

were obtained directly from the telescopic beam assembly

model (see Table 2). The overlay between the two shear

stress distributions in Figure 11 is self-validating. Both show

that the shear stress remains fairly uniform along with the

shear force across the unreinforced lengths. The tip

reactions enhance both this force and its stress within the

overlap where, again, the shear stress is fairly uniformly

distributed with the shear force (see Fig. 9). The reversal in

the tip reaction between beams AB and CD and again

between CD and EF is responsible for the alternation in

sign of the shear stress within Fig. 11. Nowhere does the

shear stress magnitude become zero despite it having a

relatively low magnitude compared to the accompanying

bending stress. As a design criterion, the application of a

limiting shear stress becomes important to shorter length

cantilever beams. This imposes a near uniform cross-

section when minimising weight [5], in marked contrast to

the taper imposed by an optimised bending design

mentioned above.

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

11EIS 31 Inners v01.indd 11 22/9/11 15:47:14

Figure 10: Telescopic beam bending stresses from FEA

and tip reaction analysis

(Key: _______ Analytical; FEA)

Figure 11: Telescopic beam shear stresses from FEA and

tip reaction analysis

(Key: _______ Analytical; FEA)

5.0 Stress Analysis for the Continuous Beam

5.1 Force and Moment Diagrams

Appendix B1-B3 outlines the analysis of the single beam

model idealised, in Figure 12. The shear force and bending

moment diagrams, shown in Figure 13, have been

constructed from the S- and M-values given in B1. Section

B.2 gives a sample calculation for the bending and shear

stresses compared in Figures 14 and 15.

5.2 Bending Stress Distributions for a Single Stepped-

Beam

Bending stresses refer to the top surface of the single

stepped beam where they attain their maximum values [3].

Analytical stress values were obtained at 50mm intervals

along the beam, as shown in Appendix B.3. Numerical

values of bending stress were obtained directly from FEA.

Figure 14 compares the bending stresses obtained from

each method (thin and thick lines respectively). Here the

Figure 12: Single Beam Model

Figure 13: Shear force and bending moment diagram for

the continuous, stepped beam

stress distribution, are those for a continuous beam, but

due to its stepped changes in area, stress discontinuities

again appear. The corresponding stepped stress reductions

differ from those found within the overlaps in a telescopic

cantilever (see Fig. 10) despite the area having been

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

12EIS 31 Inners v01.indd 12 22/9/11 15:47:15

increased by a similar amount. We have seen that in an

overlap one area bears far more stress than the other with

the greater showing here a two-fold increase over the

stepped beam value. This reveals an inherent feature of

telescoping: that each beam end within the overlap must be

stressed separately as they cannot be considered in terms

of an equivalent solid section.

It is instructive here to make a further comparison between

the overall bending stress distributions in Figs 10 and 14

when the overlaps are ignored. Thus, the maximum stress

in both beams decreases linearly from its greatest value at

the fixed-end to zero at the free-end, where the load acts.

The overall stress appears to be distributed linearly along

the entire length of the single beam when the thicker section

interruptions are ignored. In contrast, due to the tip reactions,

the overlap displaces the distribution to retain a similar

stress magnitude at its start and finish. Within the overlap

these each fall to zero at the ‘free-ends’ on either side as

shown. Comparing the overlap regions in the telescopic

beam with each region of increased area for the single

stepped beam, the stress reduction is less severe for the

former due to the effect of the reactions that exist either at

the tip positions (analytical) or the equivalent reactions

spread within the wear pad (FE). However, the stress

variation is greater across the overlap as it falls to zero at

each end. The greatest bending stress magnitude of 140

MPa in this figure shows that the structure remains elastic,

given a yield stress for a medium carbon steel of, say, 400

MPa. Their ratio, which provides safety factor of almost 3,

would be regarded as an adequate figure for a practical

design but a lower factor might be applied to achieve a weight

reduction.

5.3 Shear Stress Distributions for a Single-Stepped Beam

Shear stress values apply to the neutral planes of the beam

sections where their maximum values are attained [3].

Analytical shear stresses were found at 50mm intervals

along the neutral plane as shown in Appendix B3. Numerical

values of shear stress were obtained directly from the

telescopic beam assembly model using FEA. Comparing

Figs 13 and 15, the most significant difference between the

two shear distributions is the alternation to the sign of the

shear stress for the telescopic cantilever. This is a

consequence of the reversal in the tip reaction between

mating sections which, of course, is absent in a continuous

beam. For the latter, nowhere is the bending stress and the

shear stress zero despite their being lowered by the increase

in the section area at each step. The stress shear

magnitudes for telescopic and continuous beams are similar

at the fixed end and are fairly uniformly distributed within the

unreinforced lengths. The shear stress in the continuous

beam does not alternate between positive and negative

values but the stepped geometry provides a distribution that

is influenced by the changing cross-section. The greatest

shear stress occurs in the smallest cross-section for the

free-end length as shown. The greatest deviation between

the two predictions in Fig. 15 occurs at the step where there

appears an almost twofold increase in the peak value from

FE. Here the FE is likely to be more realistic given what is

known of the effect of sharp section changes upon stress

concentrations [6]. Everywhere the shear stress remains

positive albeit of small magnitude compared to the bending

stress values. This will always apply to long beams but for

shorter beams, where section dimensions are similar to

the length, shear can dominate. In fact, shear stress remains

an important design criterion for thin-walled sections whose

plates are at risk of local buckling in a shear mode [5].

Figure 14: Continuous beam bending stresses from FE

and Theory

(Key: _________ Analytical; FEA)

Figure 15: Continuous beam shear stresses from FE and

Theory

(Key: _________ Analytical; FEA)

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

13EIS 31 Inners v01.indd 13 22/9/11 15:47:15

7.0 Conclusions

The graphs of the beam stresses provided by applying the

two methods as well as a Finite Element Analysis to each

structure respectively are presented for comparison. On

comparison, it can be seen that there is a definitive correlation

between them. As mentioned earlier these are self validating

in nature, in that the continuous beam theory provides a

check upon numerical stress levels from FEA and, in turn,

FEA provides a check upon the analytical stresses calculated

from tip reactions within a telescopic beam. Whereas the

paper preceding this outlined the Tip Reaction Model, as an

appropriate mechanism for telescopic beams, taking into

account their discontinuity, this paper takes it a step forward,

by obtaining beam stress values for the same and then

comparing it with the established classical theory.

Comparable stress values, confirms that the model

proposed is perfectly robust for application to a telescopic

cantilever, just as is the classical theory for continuous

beams. Given that telescopic cantilevers are finding

increasing applications in today’s world of material and

design optimisation, with the focus on weight saving in

engineering applications, this theory for discontinuous

beams counterbalances the need for a numerical solution

and can be adapted as is needed for any given purpose.

References

1. Abraham, J. Estimating deflection and stress in a

telescopic cantilever beam using the tip reaction model,

Ph.D. Interim Report, School of Engineering and Design,

Brunel University, November, 2010.

2. Rees, D. W. A. Mechanics of Solids and Structures, World

Scientific, 2000.

3. Gere, J. M. and Timoshenko, S. P. Mechanics of Materials,

Van Nostrand, 1984.

4. Benham, P. P. and Crawford, R. J. Mechanics of

Engineering Materials, English Language Book Society/

Longman Group Limited, Essex, England, 1987.

5. Rees, D.W.A. Mechanics of Optimal Structural Design –

Minimum Weight Structures, Wiley 2008.

6. Peterson, R. E. Stress Concentration Factors, Wiley 1974.

APPENDIX A

A1. Tip Reactions

Referring to Fig. 3a, the tip load is W = 10 N and the distributed

self-weights are 007536.01 =w N/mm,

006594.02 =w N/mm and 005652.03 =w N/mm.

Equations, derived in Part 1 [ ], provide the tip reactions RD,

RB and R

C in Fig. 3a-d:

+=

2

1 33

2

lwWRD

α

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

Nlw

WRD 5648.1332

005652.0120030

25.0

1

2

1 33

2

=

×+=

+=

α

Similarly taking moments about D gives

−

+−×=2

)21()1(

1 2332

2

αα

α

lwWRE

N7824.962

)5.01(1200005652.0)25.01(30

25.0

1=

−×

+−×=

Similarly taking moments about C gives

)]1(2

[1

22

322

1

αα l

lR

lwRR EDB −×−×+=

)]1(2

1200006594.0[

12

1

αα

−×−×+= EDB RRR

From earlier calculations RD

= 133.5648N and RE= 96.7824N

NRB 8032.194)]1(7824.962

1200006594.05648.133[

12

1

=−×−×+=∴ αα

Balancing forces give

CDEB RRRR +×+=+ 1200006594.0

RC =194.8032 + 96.7824 - 133.5648 - 0.006594 x 1200 = 150.108N

Thus when 25.03

1,1200,1200,1000 21321 ===== αα andlll

the reactions are

NR

NR

NR

NR

E

D

C

B

7824.96

5648.133

108.150

8032.194

=

=

=

=

At the fixing A the reaction is:

RA

= 30 + 0.007536 x 1000 + 0.006594 x 1200 + 0.005652

x 1200 = 52.2312N

And the bending moment is

mmN

M A

4.108506)5001000007536.0(

)12001200006594.0()21001200005652.0()270030(

=××+

××+××+×=

14EIS 31 Inners v01.indd 14 22/9/11 15:47:16

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

15

Figure C.1: Section of the Beam above the Neutral Plane

The centroid of the section’s half-area above the neutral

plane is found from the square tube’s outer dimension d

and common thickness t = 1 mm:

)1(2

2422

1

2)2(

2

=−

××+

−−

==

d

dddd

A

yAy

i

ii

( ))1(8

462

)1(2(4

)1)(2(2222

−

++−=

−

+−−

d

ddd

d

ddd

)1(8

4632

−

+−=

d

dd

Area of cross section

=2

)1(21)2(12

12

mmdddd

−=×−+×+×

The maximum shear stress follows from Eq. 5 as follows

tId

dddSMax

2)1(8

)463()1(22

××−

+−×−×=τ

tI

ddS

24

)463(2

×

+−×=

Note: The b denominator in Ib

ySa=τ in this case is equal to

2t.

Within the overlap length CB for beam AB the bending

moment is

2

)()()( 1

111

xlxlwxlRM B

−×−×−−×−=

Once again the maximum bending stress applies to the top

surface where mmy 5.12max =

2max /9232

5.12mmN

M

I

yMMax

×−=

×−=σ

in which the sagging moment is positive.

The corresponding shear force expression is

A.2 Shear Force and Bending Moment Diagram for beam

ACB

Length AC

Shear force is = 52.2312 - 0.007536 × x where x is the

distance from A.

Bending moment

Therefore Shear force at

Bending moment at

Length CB

Shear force is = 52.2312 - 0.007536 × x + 150.108 where x

is the distance from A.

Bending moment

Therefore Shear Force at

Bending moment at

A.3 Calculation of Bending and Shear Stresses for Beam

ACB

Surface bending stress are maximum along the vertical

plane of symmetry. Within the length AC for the beam AB in

Figure 3, the bending moment at a distance from A is

The maximum bending stress applies to the top surface

where

−

−

mmNC

mmNA

2.78524

4.108506

))600(108.1502

007536.0232.52(4.108506 −×+××−×+−= xx

xx

B

C

−

0

2.78524

B

mmNC

x

2

)()()()( 1

11111

xlxlwxalRxlRM CB

−×−×−−−×+−×−=

)2

007356.02312.52(4.108506x

xx ××−×+−=

mmy 5.12max =

2max /9232

5.12mmN

M

I

yMMax

×−=

×−=σ

in which the sagging moment is positive.

The shear force in AC is given by

and the maximum shear stress lies at the mid-wall upon

neutral plane in Fig. C1.

xNS ×−= 007488.02312.52

EIS 31 Inners v01.indd 15 22/9/11 15:47:17

197.8176 N

194.8032 N

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

NxS 108.150007536.02312.52 +×−=

The maximum shear stress follows from Eq. 5 as follows

tId

dddSMax

2)1(8

)463()1(22

××−

+−×−×=τ

tI

ddS

24

)463(2

×

+−×=

Note: The b denominator in Ib

ySa=τ in this case is equal to

2t where t=1mm, from Table1.

APPENDIX B Analysis of the Single beam Model

Referring to Table 1 and Fig. 15 it is appropriate here to

construct the S and M-diagrams for the full continuous,

stepped length ACBED. However, only a sample of the stress

calculations is given; namely those for length portions AC

and CB.

B1. S- and M- Calculations (Units: N and Nmm)

Length AC

Equating forces in the vertical direction and taking W = 30 N,

gives the reaction at A

[N

RA

2312.52

)500006908.0()400014444.0()600007536.0(

=

×+×+×=

]30)90000628.0()30001319.0() +×+×+ N2312.52=

The bending moment at A is

M A )1650300013188.0()225090000628.0()270030(

=××+××+

××+××+×=

)1250500006908.0( ××+ )800400014444.0( +××+

N108506)300600007536.0( =××+

The shear force in AC at a distance x from A is

S(x) x×−= 00753.03616.33

The bending moment in AC at a distance x from A is

M(x) )2

007536.02312.52(108506x

xx ××−×+−=

The linear and parabolic expressions give their extreme

values at A and C:

Shear force at

NC

NA

7096.47

2312.52

Bending moment at

−

−

NmmC

NmmA

2.78524

108506

Length CB

Shear force is )600(006594.0007536.02312.52 −×−×−= xx

where x is the distance from A.

Bending moment

006908.0)2

007536.02312.52(108506 ×−××−×+−=x

xx

)2

)600()600(

−×−×

xx

Therefore Shear force at

NB

NC

8032.194

8176.197

Bending moment at −

0

2.78524

B

NmmC

Length BE

Shear force is )600(006594.0108.150 −×−−= x where x is

the distance from A.

Bending moment

006594.0))500(488.72312.52(108506 ×−−×−×+−= xx

)2

)600()600(

−×−×

xx

Therefore Shear force at

NE

NB

7606.38

0576.42

Bending moment at

−

−

NmmE

NmmB

2.40366

7.60570

Length ED

Shear force is

7824.968032.194)600(006594.0108.150 ++−×−−= x

where x is the distance from A.

Bending moment

)600(006594.0))500(488.72312.52(108506 −×−−×−×+−= xxx

)2

)600()

−×

x

2

)1500()1500(005652.0

−×−×−

xx

Therefore Shear force at

−

−

ND

NE

478.98

7824.96

Bending moment at

− NmmD

E

1.29289

0

Length DF

Shear force is

)1500(005652.01200006594.0488.72312.52 −×−×−−= x

where x is the distance from A.

16EIS 31 Inners v01.indd 16 22/9/11 15:47:18

ENGINEERING INTEGRITY, VOLUME 31, SEPTEMBER 2011 pp.6-17.

Bending moment

1200006594.0)500(488.73616.33(4.56541

−

××−−×−×+−= xx

)1200( −× x )2

)1800()1800(005652.0

−×−×−

xx

Therefore Shear force at

NF

ND

30

0868.35

Bending moment at −

0

1.29289

F

NmmD

The shear force diagram and the bending moment diagram

for the continuous beam are shown in Figure 12.

B.2 Calculation of Bending and Shear Stresses

Consider the sectional view of the continuous stepped beam

shown in Figure 6. The maximum bending stress apply to

line A1C

1B

1E

1D

1F

1in Fig. 9. The shear stress will be maximum

along the line A2C

2B

2E

2D

2F

2. Note that the area properties

given in A3 again apply to each square tubular section of

outer dimension d and thickness 1 mm.

Length AB

Consider, firstly, the uniform section within the length portion

AC. The bending moment at the section at a distance x from

A

M )2

007536.03616.33(4.56541x

xx ××−×+−=

Taking sagging moments as positive, the maximum bending

stress follows from Eq. 4:

2max /9232

5.12mmN

M

I

yMMax

×−=

×−=σ

The shear force in AC is given by

xNS ×−= 007488.02312.52

The maximum shear stress follows from Eq. 5 as follows

tId

dddSMax

2)1(8

)463()1(22

××−

+−×−×=τ

tI

ddS

24

)463(2

×

+−×=

Note: The b denominator in Ib

ySa=τ in this case is equal to

2t where t=1mm and I = 9232 mm4 from Table1.

Length BC

For the stepped length CB, the bending moment is

M 006908.0)2

007536.03616.33(4.56541 ×−××−×+−=x

xx

)2

)600()600(006908

−×−×

xx

Taking sagging moments as positive, and referring to Table

1 for the corresponding second moment of area for the length

BC (Section 4), the maximum bending stress follows from

Eq. 4:

2max /16345

5.12mmN

M

I

yMMax

×−=

×−=σ

The accompanying shear force is

S )600(006594.0007536.03616.33 −×−×−= xx

The maximum shear stress follows from Eq. 5 as follows

tId

dddSMax

2)1(8

)463()1(22

××−

+−×−×=τ

tI

ddS

24

)463(2

×

+−×=

Note: The b denominator in Ib

ySa=τ in this case is equal to

2t where t=2mm and I =16345N/mm2 from Table1.

17EIS 31 Inners v01.indd 17 22/9/11 15:47:18

Mechanical Testing of Micro Specimens and Semi-finished Micro ProductsBernd Köhler*, Hubert Bomas*, Hans-Werner Zoch*, Bremen, and Jens Stalkopf°, Pfungstadt

*IWT Stiftung Institut für Werkstofftechnik, Bremen, Germany

° Instron Deutschland GmbH, Pfungstadt, Germany

Technical Article

Established in 2007, the Collaborative Research Centre

747 “Micro Cold Forming - Processes, Characterisation,

Optimisation” of the German Research Foundation

(Deutsche Forschungsgemeinschaft, DFG) focuses on the

provision of processes and methods for the manufacture of

metallic micro components through metal forming

technologies. The Project B4, Component Strength, deals

with the static and dynamic investigation of the mechanical

properties of micro specimens and semi-finished micro

products. Mechanical testing of such micro specimens

requires testing equipment specifically adapted to their

small dimensions. Within the context of this special

requirements profile, this paper discusses the comparative

advantages of different testing machine types available on

the market. To conduct the above-mentioned project, the

testing system considered to be most appropriate for the

task was procured, consisting of the Instron Electropuls™

E1000 electromechanical test machine equipped with the

non-contacting Advanced Video Extensometer AVE. This

article discusses some of the insights gained in the use of

this testing system.

The Collaborative Research Center 747 of the Deutsche

Forschungsgemeinschaft “Micro Cold Forming - Processes,

Characterisation, Optimisation” was established at Bremen

University in 2007. The central focus of this Collaborative

Research Centre is the investigation of processes and

methods for the manufacture of metallic micro components

by means of metal-forming technologies, i.e. of components

which are smaller than 1 millimetre in at least two

dimensions, and less than 5 mm in the third dimension [1].

These investigations encompass all relevant aspects of

the forming process, from the development of materials to

components testing.

In this context, the Project B4, in which three of the authors

work, deals with the determination of the mechanical

properties of thin metallic semi-finished products, and

components manufactured from these products, which, in

general, cannot be derived from those of semi-finished

products and components with significantly higher wall

thickness. This is due to the statistical and technological

effect of size, the dominant influence of surface, and

dimensions in the scale of the material’s microstructure.

Micro sheets with a sheet thickness in the order of the grain

size of the material, for example, exhibit mechanical

properties which are significantly different from those of

larger-thickness sheets.

For this reason the mechanical properties of the

manufactured semi-finished products and their post-forming

behaviour in the finished component have to be analysed

thoroughly, including their behaviour during failure, with a

view to validating calculation methods and transferability of

mechanical properties. Such analyses necessitate a testing

system capable of meeting the specific requirements for

static and cyclic testing of micro specimens. The system

has to allow low forces and strokes to be set and controlled

with sufficient accuracy, and provide for a method of strain

measurement which takes into account the mechanical

sensitivity of the test specimens. For the last two years, the

Collaborative Research Centre has had a materials testing

system of this type at its disposal. The following article will

discuss some of the experience gained with this system.

Test machine for micro specimens

Critical requirements for a testing system for micro

specimens and micro components, which is to permit both

static and cyclic investigations, fall into three areas:

1. Loads: Materials and specimen dimensions

determine the load range to be covered by

the test machine. Specifically with a view to

dynamic testing, the machine must allow for

precise control of low forces.

2. Dynamics: High dynamic performance of the machine

is desirable, i.e. for a specimen with given

material and geometry, the machine should

provide for an adequate displacement

amplitude at a maximum frequency of load

cycles, whilst maintaining the preset

waveform (e.g. a sine wave).

3. Stroke: To enable static tensile and compressive

tests to be performed, an adequate piston

stroke is required.

As resonant testing machines do not permit static testing,

and both, servo-pneumatic and spindle testing machines

do not meet the above requirements with regard to dynamic

performance and controllability, only electro-dynamic or

servo-hydraulic machines are, in principle, suited to the

application in hand.

Electro-dynamically driven test machines are available on

the market in various sizes with maximum load capacities

ranging from ± 22 N up to ± 10 kN. By contrast, even the

smallest servo-hydraulic systems provide a load capacity of

18EIS 31 Inners v01.indd 18 22/9/11 15:47:19

5 kN. Depending on the strength and dimensions of the

specimens, the loads required for testing of micro

specimens can be found predominantly in the range below

1000 N, whilst thin sheets with thicknesses in the range of

10 µm require forces of less than 10 N.

Although electro-dynamic and servo-hydraulic systems

basically exhibit a comparable dynamic performance when

it comes to higher loads, even the smallest servo-hydraulic

testing machines have been shown to be hard to control

during cyclic tests with loads in the order of only a few

Newtons, due to the relatively high moving masses of the

machine. Besides, electro-dynamically driven machines

are superior to their servo-hydraulic counterparts in a number

of other ways which are shown in Figs 1 and 2 using the

example of two 10 kN machines.

Figure 1. Servohydraulic testing machine

Due to the absence of the hydraulic power pack, the electro-

dynamic testing system has a lower footprint. It does not

require a 3-phase power supply or a cooling water

connection and is less maintenance-intensive, as there are

no hydraulic hoses to replace, no oil filters or seals to change,

no oil to be replaced and properly disposed of, and no

maintenance of servo valves is required. In addition, the

testing system is characterised by low noise emission. The

electro-dynamic drive concept is therefore clearly superior

to the servo-hydraulic concept considering the requirements

profile for testing of micro specimens.

Apart from their maximum load capacity, electro-dynamic

testing machines available on the market also differ with

regard to their maximum stroke, which is particularly relevant

in the case of static tensile tests. Some of the test machines

have a maximum piston stroke of 25 mm or less. Some

electro-dynamical testing machines even require a costly

additional drive unit to apply the static load. Considering all

relevant requirements for static and cyclic mechanical

Figure 2. Electrodynamic testing machine

testing of micro specimens, an electro-dynamic testing

machine type Instron E1000 (see Fig. 3) was considered

the ideal solution.

Figure 3. Testing machine ElectropulsTM E1000

19EIS 31 Inners v01.indd 19 22/9/11 15:47:19

This test machine is driven by a brushless linear motor and

provides a maximum load capacity of ± 710 N for static tests

and ± 1000 N for cyclic tests. The machine’s test space has

a height of max. 610 mm, the maximum piston stroke is

60 mm, which is adequate for performing static tensile tests.

The piston position is measured by means of a Linear

Variable Differential Transformer (LVDT) in the setup mode,

and by means of a calibrated incremental transducer in the

displacement control mode. Two appendant Dynacell load

cells calibrated to ISO 7500-1 with measuring ranges of

± 2kN and ± 250 N, respectively, and automatic inertia

compensation are available for load measurement.

Special attention was given in the selection of the test system

to the accuracy of load control for small loads and in cyclic

operation. Figure 4 shows the variation of the load amplitude

for a cyclic tensile test under sinusoidal load at a stress

ratio R = 0.1 and a frequency f = 20 Hz. The specimen was a

micro rotary swaged wire made from steel grade 1.4301

with a diameter of 0.5 mm. The graph shows the feedback

load amplitude at a command value of Fa

= 40.5 N. The

average load feedback amplitude determined over 2000 load

cycles is Fa = 40.487 N with a standard deviation of

s = 0.055 N. The first 1000 cycles were not taken into account

in the calculation of the mean value, to ensure that the result

is not distorted by the process of stabilisation. Normalisation

of the standard deviation with respect to the measuring range

of the load cell used provides:

sn = s/250 N = 0.00022 = 0.022 %

Figure 4. Fluctuation of load amplitude during cyclic test

In contrast to mechanical testing with resonant testing

machines, the linear motor driven electro-dynamic system

enables the testing frequency to be varied within certain

limits. The dynamic performance of the testing system is

shown by way of example in Fig. 5 which illustrates the

relationship between the testing frequency and the

achievable displacement amplitude for three different

loading conditions. The curve plotted without a specimen

installed represents a limiting curve resulting from the

maximum achievable acceleration of the moving masses.

Looking at the plot with installed specimen at a static mean

load of 200 N and a load amplitude of 100 N, you will find

that a significant deviation from the limiting curve does not

occur until a frequency above 100 Hz has been reached.

When the mean load is increased to 500 N and the amplitude

to 500 N, the curve shifts towards lower frequencies, i.e. a

given displacement amplitude will not be achievable under

these conditions unless the test frequency is reduced.

Basically, the performance diagram shows that testing

frequencies of 100 Hz can be achieved with the testing

system in cyclic tests, provided that the stiffness of the

specimen is adequate.

Figure 5. Dynamic performance plot of the testing

machine ElectropulsTM E1000

No-contact strain measurement

In view of the micro dimensions of the test specimens (typical

sheet thickness ranges between 10 µm and 100 µm), strain

measurement using specimen-contacting methods such

as strain gauges or clip-on extensometers is not feasible.

On the one hand, such methods involve the danger of

damaging the specimens during the attachment of the

respective strain measurement device, on the other hand,

the impact of these measuring methods on the result can

no longer be neglected, as it can be with larger specimens.

For this reason, a non-contacting optical strain

measurement method was chosen.

The system supplier provides such a solution as part of the

ElectroPuls testing system in the form of the so called

Advanced Video Extensometer (AVE), see Fig. 6. Essentially,

20EIS 31 Inners v01.indd 20 22/9/11 15:47:19

the AVE consists of a high-resolution digital video camera

and an LED light source, which illuminates the specimen

with pulsed, monochromatic, red, polarised light with a

wavelength of 650 nm.

For the application in hand, the video camera is configured

with a lens system optimised for small specimens, which

has a focal length of 55 mm and permits a viewing field of

60 mm in the axial direction, and 8 mm in the transverse

direction. Strain measurement is achieved by tracing the

axial movement of markings applied on the specimen with

the video camera, and calculating strain by means of a real-

time image processing system.

Figure 6. Video extensometer AVE (a) with integral

illumination unit (b)

Measurement of the original gauge length, which is defined

by the markings on the specimen and which is essential for

strain measurement, is achieved prior to the test by the

calibrated AVE, with an absolute accuracy of ± 2.5 µm. The

markings take the form of two spots with a diameter between

0.5 and 3 mm (Fig. 7), or alternatively lines with a thickness

between 0.25 and 2.5 mm, which can be applied in different

ways, e.g. by means of a suitable marker pen or by means

of a template, or by means of adhesive spots.

A suitable choice of colour has to be made to ensure

adequate contrast between the marking and the background

colour. In addition, a second polarisation filter in front of the

camera lens works as analyser, suppressing undesirable

Figure 7. Gauge marks applied to a tensile specimen for

theAVE

reflections from the specimen surface and enabling

optimum boundary definition between the marking and the

specimen surface. In addition, an electronic bandpass filter

in the camera ensures that only light with the wavelength of

the mono-chromatic light source can pass, such that the

influence of ambient lighting is eliminated. During the

measurement, the centres of gravity of the markings are

computed in real time and the strain is determined from

their distance.

This eliminates potential errors due to a deformation of the

markings under the influence of high strains. The minimum

original gauge length, i.e. the distance between the markings

at the beginning of the test, is 5 mm in the case of the camera

lens used, maximum tracking speed for the markings is

150 mm/min. When the 55 mm lens is used, the resolution

for displacement measurement is 0.5 µm, absolute

accuracy is 2.5 µm or 0.5 % of gauge length, whichever is

greater.

Figure 8 shows the results of static tensile tests conducted

on flat specimens with the shape shown in Figure 9. The

test measured the yield strength Rp0.2

, tensile strength Rm

and elongation after fracture A of Al-99.5 micro sheets having

a sheet thickness of 100 µm at various test velocities. The

test system enabled the strain rate to be varied over more

than two orders of magnitude, and the AVE enabled strain to

be measured up to a nominal test velocity of 5 mm/s,

equivalent to a strain rate of more than 0.2 s-1

Apart from measuring axial strain, the AVE also permits

measurement in the transverse direction, meeting the

requirements of ASTM E 8, EN 10001-1 and ISO 6892 for

testing of metals.

21EIS 31 Inners v01.indd 21 22/9/11 15:47:20

Figure 8. Mechanical properties of micro-flat-specimen

of Al 99.5 (thickness 100 µm) in dependence

of the strain rate

Figure 9. Sketch of the tensile specimen

With the help of the ElectroPuls testing system it has been

possible, in cooperation with other Project Areas of the DFG

Collaborative Unit, to make contributions in various fields:

The further development of a PVD-based manufacturing

process for AlSc micro sheets was supported by extensive

studies of their physical properties [2]. In addition, the

mechanical variables determined were used for the

optimisation of micro cold forming processes such as deep

drawing [3] and applied in FEM simulations [4]. Last, but not

least, differences were observed in the mechanical

properties of micro specimens [5], which can be attributed

to typical size effects occurring on transition into the micro

range [6]. On the whole, the test system described here has

proven itself as a valuable and flexible tool for the DFG

Collaborative Research Centre 747 for meeting the wide

spectrum of requirements in the static and dynamic testing

of micro specimens and components.

Acknowledgements

The authors would like to thank Deutsche

Forschungsgemeinschaft (DFG) for their beneficial support

provided during these studies within the framework of the

Project B4 “Component strength” of the Collaborative

Research Centre 747 “Micro Cold Forming – Processes,

Characterisation, Optimisation”.

Literature references

1 F. Vollertsen: Size effects in manufacturing, F. Vollertsen,

F. Hollmann (Hrsg.): Strahltechnik vol. 24, BIAS Verlag

Bremen (2003), S. 1-9, ISBN 3-933762-14-6.

2 H.-R. Stock, B. Köhler, H. Bomas, H.-W. Zoch: Properties

of aluminium-scandium alloy thin sheets produced by

physical vapour deposition, Materials and Design, 31

(2010) 576-581.

3 F. Vollertsen, Z. Hu, H.-R. Stock, B. Koehler: On the limit

drawing ratio of magnetron sputtered aluminium-

scandium foils within micro dee drawing, Prod. Eng. Res.

Devel. 4, 5 (2010) 451-456.

4 P. Bobrov, J. Lütjens, J. Montalvo Urquizo, W. Wosniok, M.

Hunkel, A. Schmidt, J. Timm: Zu einer

verteilungsbasierten Modellierung von Mikrowerkstoffen,

F. Vollertsen, S. Büttgenbach, O. Kraft, W. Michaeli (Hrsg.):

4. Kolloquium Mikroproduktion, BIAS Verlag Bremen

(2009), S. 235-242, ISBN 978-3-933762-32-0.

5 B. Köhler, H. Bomas, J. Lütjens, M. Hunkel, H.-W. Zoch:

Yield strength behaviour of carbon steel microsheets

after cold forming and after annealing, Scripta Mat. 62

(2010) 548-555.

6 F. Vollertsen, D. Biermann, H. N. Hansen, I. S. Jawahir,

K. Kuzman: Size effects in manufacturing of metallic

components, CIRP Annals – Manufacturing Technology

58, 2 (2009) 566-587.

22EIS 31 Inners v01.indd 22 22/9/11 15:47:20

Report on EIS Forum “Seven posters - is that three too many?”The forum took place at the annual EIS instrumentation

exhibition at Silverstone on 8th March. It was chaired by Colin

Dodds with an invited panel of guest speakers: David Hamer

from Lotus Renault GP, David Purdy from Cranfield University,

Defence Academy, Bruce Oliver from Lola Cars and Bernard

Steeples ex Ford and now an engineering consultant.

Colin opened the proceedings with a short presentation

describing the 7-post application and how it differed from

the classic 4-post road simulator and then, each guest

speaker took it in turn to express his views on the subject

before opening up the topic to short presentations and

questions from the floor.

Since the F1 application was the main interest at Silverstone

the discussion focused more on the performance (ride and

handling, leading to lap time) side rather than structural

integrity. A consensus agreed that the 7-post was best suited

to refining dynamic response of a F1 car and had little

application elsewhere whereas the 4-post system has a

plethora of applications ranging from full vehicle durability,

ride, packaging studies and dynamic response.

The session closed with a presentation by Chris Lamming

from the University of Bath who discussed control techniques

for aero-loaders.

The feedback was positive from a number of attendees and

this type of forum may become an annual event coupled

with the instrumentation exhibition. However, there was fear

that the forum detracted from attendance at the exhibition;

the exhibition attendance was small in the afternoon. This

should be resolved prior to introducing the forum as an

annual event. That said, the forum was a success.

ENGINEERING INTEGRITY SOCIETY

CORPORATE SPONSORSHIP APPLICATION FORM

Corporate Sponsorship for 2011 is £400+VAT (pro rata). All Corporate members receive discounts at seminars,

training course and exhibitions and advance notice where booking is required. They receive FREE copies of the EIS

Journal and get priority booking in Exhibitions when space is limited.

We would like to join the EIS as a Corporate Sponsor.

Contact Information:

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Sponsor’s Representative: Name: ------------------------------------------------------------------------ Title: ------------------

Please keep our representative informed of the activities of the:

(i) DURABILITY AND FATIGUE GROUP

(ii) SIMULATION, TEST AND MEASUREMENT GROUP

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We enclose a cheque for £....................................... made payable to ‘Engineering Integrity Society’.

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How to join: You can email lmansfield@e-i-s.org.uk for further information or mail the above form with a cheque to:

Engineering Integrity Society, 18 Oak Close, Bedworth, Warwickshire, CV12 9AJ.

23EIS 31 Inners v01.indd 23 22/9/11 15:47:21

Industry NewsWelcome to the Industry News

section of the journal. Thank you to

everyone for their submissions, of

which we received over 500 press

releases. The nominal limit for entry

is 200 words, which should be sent

to eis@amberinstruments.com or

posted to EIS, c/o Amber Instruments

Ltd, Dunston House, Dunston Road,

Chesterfield, S41 9QD. We would

appreciate you not sending entries

by fax.

Paul Armstrong

Exeter study brings brain-like

computing a step closer to reality

The development of ‘brain- l ike’

computers has taken a major step

forward with the publ icat ion of

research led by the University of

Exeter.

Published in the journal Advanced

Mater ials and funded by the

Engineering and Physical Sciences

Research Council, the study involved

the f i rst ever demonstrat ion of

simultaneous information

processing and storage using

phase-change materials. This new

technique could revolut ionise

computing by making computers

faster and more energy-efficient, as

well as making them more closely

resemble biological systems.

Computers current ly deal with

processing and memory separately,

resul t ing in a speed and power

‘bottleneck’ caused by the need to

continually move data around. This

is totally unlike anything in biology,

for example in human brains, where

no real distinction is made between

memory and computat ion. To

perform these two funct ions

simultaneously the University of

Exeter research team used phase-

change materials, a kind of semi-

conductor that exhibits remarkable

properties.

Their study demonstrates

conclusively that phase-change

materials can store and process

information simultaneously. It also

shows experimentally for the first

time that they can perform general-

purpose computing operations, such

as addit ion, subtract ion,

multiplication and division. More

str ik ingly perhaps i t shows that

phase-change mater ials can be

used to make artificial neurons and

synapses. This means that an

artificial system made entirely from

phase-change devices could

potent ial ly learn and process

information in a similar way to our

own brains.

CPT receives investment boost for

its ‘green’ car technology

The UK Low Carbon Innovation Fund

(LCIF), based at the University of

East Anglia (UEA), has invested

£400,000 in new automotive

technologies designed to improve

fuel efficiency and reduce carbon

emissions.

Control led Power Technologies

(CPT) has developed a range of

products to help car makers meet

t ightening legislat ion on CO2

emissions by making the car

signif icant ly more fuel eff ic ient,

through mild electric hybridisation,

without the need to redesign the car

or the car engine. The UK Essex-

based specialists have a range of

products currently in development.

CPT chief executive Nick Pascoe

said: “Although we are now working

on applications around the world, our

products and technologies have all

been developed by our experienced

and growing team of engineers in

the East of England and we are

proud of our roots here. LCIF joins

the list of our major shareholders at

an exciting stage as we work to bring

our more developed products to

market. We welcome and appreciate

LCIF’s support and its recognition of

the fruits of our work since the launch

of CPT in 2008.”

Launched in 2010, the Low Carbon

Innovation Fund is part of a £20

million venture capital investment

programme, including an £8m

contr ibut ion from the European

Regional Development Fund. The

fund, which is based at the University

of East Anglia, invests in SMEs

across the East of England – a region

which aspires to become a leading,

world class low carbon economy.

Companies interested in seeking

investment from the fund should

contact Kevin Murphy on 0207

2481506.

Further detai ls can be found at

www.lowcarbonfund.co.uk and

www.cpowert.com/

UK first as TfL installs eco-lighting

in a London road tunnel

In a UK-first, innovative, eco-friendly

lights have been installed in a central

London tunnel by Transport for

London (TfL) helping to improve

safety, reduce maintenance closures

as well as cut energy consumption

and costs.

The Upper Thames Street

westbound tunnel is now entirely lit

with low energy, long-life LED (Light

Emitting Diode) lights providing a

host of benefits for Londoners. The

design and colour of the lights is

designed to improve visibility for

24EIS 31 Inners v01.indd 24 22/9/11 15:47:21

cyclists and motorists to boost safety.

The l ights wi l l a lso cut CO2

emissions by more than 60 per cent

compared with convent ional

systems, helping to reduce TfL’s

energy bills. Projections show the

cost of lighting the tunnel could fall

from around £50,000 each year to

less than £10,000, del iver ing a

potential annual saving of at least

£40,000. The innovative lights are

also expected to last for 20 years as

opposed to the existing system’s two

year life span, significantly reducing

the need for maintenance closures.

Upgrading the lighting system in

Upper Thames Street tunnel is just

one way the Mayor of London and TfL

are working together to make the

Capital cleaner and greener. London

is already leading the way on the

introduction of hydrogen buses and

electric vehicles while the Capital’s

cycle revolution is increasing the

numbers of bikes on the streets and

improving cycling safety.

Subject to funding, it is hoped that

further schemes can be developed

across London, delivering further

benefits to road users across the

Capital.

‘Walking Chair’ could be step-up for

disabled access

A student inspired by moving

sculptures has designed a prototype

‘walking chair’ that he hopes could

go on to give people with mobility

problems greater freedom.

Martin Harris, 21 – who is about to

complete his BA (Hons) Product

Design degree at the University of

Derby – developed his battery-

powered chair, which uses metal

legs instead of wheels, after seeing

the ‘walking sculptures’ of Dutch

artist and engineer Theo Jansen.

Martin, originally from Birmingham,

said: “I first saw Theo Jansen’s work

many years ago, he calls the walking

sculptures Strandbeests. The

walking mechanism had so much

potential and I wanted to put it to a

practical purpose.”

Instead of wheels the chair moves

on a dozen legs, six on each side,

which are made up of 216 separate

pieces bolted together. The ‘one size

fits all’ seat is completely adjustable,

so it will comfortably accommodate

anybody.

The prototype can move at the

maximum wheelchair speed limit of

four miles per hour. It is powered by

standard wheelchair batteries and

motors, which gives it a range of

several miles on a single charge.

Mart in added: “Most motor ised

wheelchairs are optimised to work

indoors or outdoors, not both. The

walking chair is compact enough for

use indoors whilst also having the

all-terrain ability to cross soft surfaces,

such as sand or grass, which can prove

difficult for wheeled chairs.

“This design is a prototype, and I’d

be happy to see someone take up

the concept and develop it further, for

commercial use.”

Robotics Centre to pave the way for

robots of tomorrow

A groundbreaking new robot ics

centre set to make signi f icant

technological advances, including

developing assistive robots to help

chi ldren and adults with special

needs, has been launched by the

University of Sheffield and Sheffield

Hallam University.

The Sheffield Centre for Robotics

(SCentRo) wi l l combine the

expertise from both universities in a

bid to boost research into the

creation of animal-like robots, self-

driving cars, robots for the farms of

the future and robots that can

intelligently communicate with humans.

Devices on display at this year’s

Towards Automatic Robot ics

Systems (TAROS) conference

included:

• Shrewbot - a unique animal-like

robot that can seek out and identify

objects with its artificial whiskers

using a new technology that was

developed jointly by the Active

Touch Laboratory at the University

of Sheffield and Bristol Robotics

Laboratory. The technology will

enable the robot to function in

spaces where vision cannot be used.

• Guardians – firefighter assisting

robots developed by Sheff ield

Hallam University.

• Grail - a robotic arm designed for

use in domest ic and cater ing

scenarios developed by the

Universi ty of Sheff ie ld’s

Department of Automatic Control

and Systems Engineering.

• The Tact i le Helmet - a super-

sensing helmet being developed

by the University of Sheffield’s

Department of Psychology to help

firefighters find their way in smoke-

filled buildings. The helmet works

by detecting walls and obstacles

through an ul trasound sensor

which converts the signal to a

tactile stimulus such as a buzz on

the head when near a wall.

SCentRo, visit: www.scentro.ac.uk

25EIS 31 Inners v01.indd 25 22/9/11 15:47:21

Industry NewsThe Infrastructure Show

(NEC,Birmingham, 17-19 October)

The show will offer visitors a fresh

insight into major rail infrastructure

projects alongside the opportunity to

understand how these schemes are

managed to reduce environmental

impact and meet spending targets

plus the chance to learn about the

latest product and system

innovations in the sector.

A major highlight of the show will be

its sector-focused hubs and Keynote

Theatre, featuring expert speakers

from Network Rail, Crossrail, HS2,

London Underground and others in

a series of free-to-attend talks. The

Rail hub will also provide a forum for

vis i tors to meet with special ist

suppliers and manufacturers and

see major project updates from the

biggest clients.

A diverse range of leading sector

suppl iers and manufacturers

showcasing the latest product

innovations will also be attending

The Infrastructure Show. Among the

major exhibitors already confirmed

for the event are ACO Technologies,

Cleshar Contract Services, Costain,

CPM Group, CU Phosco Lighting,

JCB, Peri Ltd, Severn Trent Services,

Vinci Construction UK Korec Kosran,

RMD Kwikform, Tony Gee & Partners

and Topcon.

A full exhibitor list is available from

www.infrastructure-show.com

500,000 tonnes of vehicle CO2

emissions could be saved in London

with Start/Stop technology

Fol lowing the announcement by

Transport Secretary Phi l ip

Hammond of the creation of a ‘Clean

Air Fund’ to improve air quality in

London, including such measures as

a ‘no-idling zone’, Bosch believes

that the use of Start/Stop technology

for vehicles in London could reduce

CO2 emissions by over 500,000

tonnes annually.

”Bosch is at the forefront of

developing technologies to make

gasoline and diesel engines more

efficient and less polluting”, said

Peter Fouquet, President of Bosch in

the UK.

The system works by automatically

switching off a vehicle’s engine when

it comes to a stop, for example at

traff ic l ights. When the clutch is

depressed, or the foot is taken off the

brake pedal for an automatic

transmission, the engine restarts

seamlessly in a fraction of a second.

”A Start/Stop system can reduce a

vehicle’s CO2 emissions by 8

percent in average city driving, and

up to 15 percent in dense city traffic.

In addit ion, the technology also

reduces noise pollution”, Fouquet

said. “The benefit can be further

improved when a Bosch ul tra-

eff ic ient al ternator is added.”

See Bosch’s Start/Stop system in

action for vehicles with both manual

and automatic transmissions via the

following link:

w w w . y o u t u b e . c o m / u s e r /

boschautomotive

University doubts after ‘A’ level

results? - Current students

recommend a working gap year

despite the fee increases.

Students struggling with their options

in the light of their ‘A’ level results

have clear advice from a survey of

current university students who took

a working gap year with ‘The Year in

Industry’ programme (YINI). They are

overwhelmingly recommending that

‘A’ level students in relevant subjects

should in pr inciple go on the

programme, with 94% of those

surveyed saying they would

recommend the programme, and,

significantly, only one in six see the

2012 fee increase as presenting a

strong reason not to undertake this

career changing paid gap year in

2011/12.

‘The Year in Industry’ programme, run

by educat ional chari ty EDT,

specialises in placing students on a

paid working gap year with leading

engineering, technology or science

companies.

The survey results throw the benefits

of a working gap year through “The

Year in Industry” into sharp focus:

• 94% said YINI had helped them

decide their career preferences

• 97% said YINI had made them

more employable

• 75% said it had helped them in

their degree studies

Turing Bombe rebuild team leader

recognised with honorary doctorate

On the 4th June 2011, John Harper

was among over 200 students

receiving various qualifications from

the Open University at Ely cathedral

but what made John special was he

was the only one receiving an

honorary doctorate. The Open

University presented John with this

honour in recognition of his work,

leading a team of talented volunteers

to recreate the Turing Welchman

Bombe at Bletchley Park.

John Harper, a qualified chartered

engineer, is a key member of those

26EIS 31 Inners v01.indd 26 22/9/11 15:47:22

visionary enthusiasts who undertook

the long and complex process of

recreating the technology of World

War Two. He has been the driving

force in preserving much historical

material in danger of being lost,

persuasively obtaining funding,

industrial and governmental support,

of ten in an environment of

disinterest.

The World War Two Bombe Rebuild

is on public display at Bletchley Park,

and is normally demonstrated at

weekends.

www.bletchleypark.org.uk

Dedication of Bletchley Park

Memorial by HM The Queen

Her Majesty The Queen dedicated a

public memorial at Bletchley Park,

Milton Keynes, Buckinghamshire on

Friday 15 July, to commemorate all

those that provided vital service at

Bletchley Park and its ‘Outstations’

during World War II.

This was The Queen and Duke of

Edinburgh’s first visit to the home of

the wartime code breakers. They

were accompanied throughout the

visi t by Sir Francis Richards,

Chairman of the Bletchley Park Board

of Trustees and Simon Greenish,

Director of the Bletchley Park Trust.

The Royal Party was provided with a

short tour of the museum and shown

some of the restoration projects

which have taken place at Bletchley

Park to rebuild the machines which

assisted with the wartime decryption

of enemy codes. These included the

Turing Bombe, brainchi ld of

mathematical genius Alan Turing,

and Colossus, the world’s f i rst

electronic computer. The Queen was

also shown an Enigma machine and

given a demonstration of how it

worked.

Following the ceremony, The Queen

was shown the Roll of Honour which

lists the names of all of those who

served at Bletchley Park and its

‘Outstations’ during the War. This

has been compiled over a number of

years and includes nearly 11,000

names.

www.bletchleypark.org.uk

Engineers find leaky pipes with

Artificial Intelligence

University of Exeter engineers have

pioneered new methods for

detecting leaky pipes and identifying

f lood r isks with technologies

normally used for computer game

graphics and Artificial Intelligence.

These techniques could help to

identify water supply and flooding

problems more quickly than ever

before, potentially saving people from

the traumatic experience of flooding

or not having water on tap.

Existing methods for detecting leaks

often result in false, so-called ‘ghost’

alarms. Universi ty of Exeter

engineers have developed a new

approach, based on technology

originally developed in the field of

Art i f ic ial Intel l igence. The new

technology is implemented as a

piece of software located on a

computer in the control room of a

water company. The software

cont inuously receives and

processes data coming from the flow

and pressure sensors installed in

the water system. It then searches

for anomal ies indicat ing the

presence of the leak. When a

potential problem is identified, an

alarm is generated to noti fy the

control room operator. The operator

also receives information on the likely

location of the leak and suggestions

of immediate act ions to take to

isolate it.

F1 in Schools™ out and about at

Silverstone, London, Goodwood and

Grove.

F1 in Schools™ had a busy couple

of weeks in July with the initiative

flying the flag for young engineering

talent and showcasing winners of its

innovat ive Formula 1™ l inked

education programme at a number

of high profile events.

The Santander Formula 1 British

Grand Prix was the highlight of the

year for winners of F1 in Schools

2011 National Finals Awards, with

eight teams visiting this prestigious

event on the Bri t ish sport ing

calendar. Prior to the Grand Prix

weekend the reigning UK F1 in

Schools champions, ‘Dynamic’, from

St. John Payne Cathol ic

Comprehensive School in

Chelmsford, Essex, were guests of

Hilton Racing for a high profile media

event, the Hilton on Park Lane Pit Stop

Challenge. A group of UAE primary

school students flew in to the UK to

link with the Bloodhound SSC land

speed record project at the

Goodwood Festival of Speed earlier

this month and this week teams of

9-11 year old primary school students

competed at the T1 Primary Racing

Challenge 2011 finals, supported by

F1 in Schools, held at the Williams

F1 team HQ.

For further information about F1 in

Schools visit www.f1inschools.co.uk.

27EIS 31 Inners v01.indd 27 22/9/11 15:47:22

Product Newsand dry gas applications.

The fast response times, combined

with high pressure and flow

capabilities, make the E-Series

solenoid valves ideal for use in a wide

range of applications, including

medical and respiratory healthcare

instruments, printing machinery and

sorting equipment, automated

packaging and air monitoring systems.

Gems Sensors and Controls,

Basingstoke, Hampshire.

Tel: +44 (0)1256 320244.

Email: sales@gems-sensors.co.uk

Electric motion control system for

Wimbledon Centre Court retractable

roof

Moog Industrial Group, a division of

Moog Inc. (NYSE: MOG.A and MOG.B)

has signed a new 5 year contract with

SCX Special Projects, Sheffield, UK to

continue its support of the motion

control system for the Wimbledon

Centre Court Retractable Roof, London

until August 2015. The new service and

support contract is managed by Moog’s

operation based in Tewkesbury, UK.

Since the installation of the retractable

roof in 2009, Moog’s motion control

system has helped ensure

uninterrupted play during all weather

for tennis fans worldwide throughout

the 2009 and 2010 Wimbledon

Championships. The new contract is

now set to continue this successful run

until 2015.

Easy to use modular test controller

from MOOG handles wide range of

tasks

Moog’s latest test controller is intended

for simple and complex tests on

components, materials and vehicles.

The new Modular Test Controller is the

latest addition to a family that already

includes larger units dedicated to

aerospace and automotive testing, as

well as the Portable Test Controller.

Based on input from customers at

leading material, automotive and

offering users the latest technologies

as part of the complete vibration test

solution from Brüel & Kjær.

Both of the new variants promise to save

time and simplify testing procedures

by virtually guaranteeing signal under-

ranges and overloads are eliminated.

This is thanks to dual, parallel A/Ds that

deliver an exceptionally wide 130 dB

dynamic range for the input channels,

without the need for programmable

voltage range circuitry.

Bruel & Kjaer, Royston, Herts.

Tel: 01763 255 780, www.bksv.com

Net shape steel and titanium castings

Over the years, Castings Technology

International (Cti) has perfected the

manufacture of castings from

precision-machined polystyrene

patterns. As in the Lost Wax process,

layers of ceramic are built up on the

pattern, which is removed on firing to

leave an inert ceramic shell mould.

These can be used to produce

prototype Replicast® castings and to

meet a market need for short lead-time,

one-off and low volume castings.

More recently the MEGAshell®

technology has enabled exceptionally

large ceramic shell moulds to be

produced to deliver the benefits of

Replicast® of a size and weight far

greater than most casting

manufacturers would have believed

possible.

Castings Technology Int., Rotherham,

South Yorks. Tel: 0114 2541166, Email:

m.ashton@castingstechnology.com,

New low energy solenoid valves from

Gems Sensors give fast response and

high flow

Gems Sensors & Controls, a global

market leader in fluid sensing and

control solutions, has introduced the

energy efficient E Series family of

pneumatic solenoid valves, specifically

engineered to give fast response and

high flow rates in a wide range of air

New release of computing software

The latest, substantial new release of

Maple™, the flagship technical

computing software for

mathematicians, engineers and

scientists from Maplesoft™ (Waterloo,

Canada), has over 270 new

mathematical functions and over a

thousand enhancements to existing

algorithms. Now available from Adept

Scientific (Letchworth, Herts), Maple

15’s record-breaking solvers for

differential equations is just one of

many new advances in Maple 15 which

enables customers to solve more

complex problems even faster.

Adept Scientific, Letchworth, Herts.

Tel: 01462 480055.

Email:leads@adeptscience.co.uk

10 MHz USB data acquisition module

with two isolated Analog inputs

Data Translation announces the

release of a cutting-edge data

acquisition module that sets new

standards in 16-bit high-speed data

acquisition via USB 2.0. With up to 10

MHz signal sampling and direct

streaming to the PC, the new DT9862

can provide twice the USB throughput

rates achievable with comparable

solutions currently available on the

market. All I/O channels are galvanically

isolated to ensure ultra-high

measurement accuracy and signal

integrity. In addition, the new module

also features flexible clock and trigger

functions (e.g. pre-, post- and about-

trigger modes).

Data Translation GmbH, Germany.

Tel: +49 (0)7142/95 31-0.

www.datatranslation.eu

Good vibrations

Sound and vibration leader, Brüel &

Kjær, has released its next-generation

vibration controller. Type 7541 and 7542

vibration controllers are designed to

meet the requirements of vibration

testing for production test applications,

28EIS 31 Inners v01.indd 28 22/9/11 15:47:23

aerospace test laboratories, it provides

for efficient operation in an array of

testing applications, including shock

absorber tests, single-axis test

systems, vibration and performance

evaluation tests.

Moog, Nieuw-Vennep, The

Netherlands. Tel: +31 (0)25 246 2034.

New motorized pendulum impact

testing system for increased

productivity and operator safety

Available in capacities from 300 via

450, 600 and 750, up to 900 J, Instron’s

newly developed MPX motorized

pendulum impact testers are ideally

designed for testing metals to Charpy

and Izod standards. Thanks to their

motor-driven raising of hammer with

auto-return after test, all MPX systems

are quick and easy to operate for

increased productivity and operator

safety. An electromagnetic brake/clutch

control allows the hammer to be safely

dropped, whilst its dual latch design

prevents accidental release and a

safety enclosure with interlocks

prevents the hammer from dropping

and stops movement when any door is

open. An adjustable latch height allows

for lower pendulum energy/velocity.

Instron Deutschland GmbH,

Pfungstadt, Germany.

Tel: +44 (0) 6157 4029 600.

LMS-InterAC partnership completes

the LMS Acoustic Simulation

solutions to cover the full frequency

range.

Recent distribution agreement brings

best-in-class Statistical Energy

Analysis (SEA) technology to the

world’s leading acoustic simulation

package.

LMS International and InterAC have

signed a strategic partnership to

distribute InterAC’s SEA+, SEAVirt and

related SEA modules to complement

the market-leading LMS Virtual.Lab

Acoustics package. In the world of

vibro-acoustic simulation, SEA is a

technology that provides a reliable

solution for high frequency problems

as well as full system vibro-acoustic

evaluation.

As acoustics takes more of a defining

role in product development, vibro-

acoustic engineers need better tools

to assess concepts and early stage

designs. Unlike other methods, SEA

does not require geometrical details,

but merely global system properties.

This is why SEA is ideal early in the

concept phase when design details,

like CAD or a FEM mesh, are not available.

www.lmsintl.com

PULS UK introduces life expectancy

data logging to QS/QT 40 power

supplies

Leading Din Rail power supply

manufacturer PULS UK has introduced

data logging to its single-phase QS40

and three-phase QT40 1 kW units. The

move will enable the company to

establish life expectancy figures based

on actual in service conditions.

PULS uses semi conductor technology

to collect data relating to operating

temperature, input voltages and other

vital information which can later be

downloaded to calculate the life

expectancy of the product. The company

is also developing a version that can

be downloaded externally allowing

customers to monitor the condition of

the power supply and schedule its

replacement during normal

maintenance programmes. PULS

expects its new technology to be

particularly effective in mission critical

applications, such as oil and gas

installations, where power failure could

result in serious consequences for

operators.

Power supply manufacturers use MTBF

(Mean Time Between Failure)

procedures to estimate the life

expectancy of their products using

accepted industry figures; but PULS is

the first to provide accurate information

based on real-life operating conditions.

Toyohashi Tech researchers (Japan)

develop magnonic crystal-based

ultra-high sensitive magnetic fields

sensors for monitoring heart and

brain activity and room temperature

High sensitivity magnetic sensors are

important in medical diagnostics for

applications such as monitoring heart

and brain activities, where mapping

distributions of localized extremely

weak magnetic fields arising from

these organs could provide early

warning of life threatening diseases

and malfunction.

Mitsuteru Inoue and colleagues at

Toyohashi University of Technology

(Toyohashi Tech) have developed high

sensitivity magnetic sensors using

magnonic crystals—artificial magnetic

crystal structures capable of controlling

the propagation of magnetostatic

waves. Magnonic crystals support the

propagation of magnetostatic waves

through the crystal spin system or

suppress the propagation of waves due

to the periodicity of the crystal structure.

Contact: Ms. Junko Sugaya and Mr.

Masashi Yamaguchi, International

Affairs Division Tel: (+81) 0532-44-

2042, E-mail:ryugaku@office.tut.ac.jp

New Sidewinder(TM) reference

design can provide a complete base

station on a single PCB

Cambridge Consultants, a leading

design and development firm, has

launched Sidewinder(TM), the smallest

commercially available 2G and 3G

small-cell platform. Ideal for use in

mobile phone communications and

professional radio, Sidewinder is

software configurable between GSM/

GPRS/EDGE, WCDMA/HSPA+ and

other SDR applications, providing new

levels of adaptability for cellular base

stations. It offers a low cost of entry for

companies wishing to exploit these

standards and sets a new benchmark

in flexible, cost effective designs.

Contact: +44 (0)208 408 8000.

29EIS 31 Inners v01.indd 29 22/9/11 15:47:23

The Engineering Integrity Society is an independent charitable organisation, supported and sponsored by industry.The Society is committed to promoting events and publications, providing a forum for experienced engineersand new graduates to discuss current issues and new technologies. We aim for both company and personaldevelopment and to inspire newly qualified engineers to develop their chosen profession.

Events run provide an ideal opportunity for engineers to meet others who operate in similar fields of activity overcoffee and lunch. All of our events enable engineers to establish and renew an excellent ‘contact’ base whilekeeping up to date with new technology and developments in their field of interest.

We are involved in a wide range of Industrial sectors including Automotive, Aerospace, Civil, Petrochemical etcand continue to be interested in new members from all sectors.

None of the above can be done without your continued support!

Act now and become an EIS Member today.

Benefits:EIS members receive a subscription to ‘Engineering Integrity’, mailed direct to your office or private address.Discounts to EIS events. CDs with all the information the Society holds on file of presentations and overheadsfrom conferences past to present. Plus access to Task Groups, to take part, or to receive information andrecommendations.

I would like to join the EIS for an annual fee of £25

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Thank you for becoming a member of the Engineering Integrity Society.

Registered in England No. 1959979 Registered Office: 18 Oak Close, Bedworth, CV12 9AJ VAT No. GB 443 7696 18 Registered Charity No. 327121

EIS 31 Inners v01.indd 30 22/9/11 15:47:24

Profile of Company MembersAdept Scientific plc

Amor Way

Letchworth

Herts

SG6 1ZA

UK

Tel: +44(0)1462 480055

Fax: +44(0)1642 480213

Website: www.adeptscience.co.uk

Adept Scientific is one of the world’s leading suppliers of

software and hardware products for research, scientific,

engineering and technical applications on desktop

computers.

Adept’s customer base includes world-leading technology-

based manufacturing corporations, universities in the UK,

Ireland, Germany and Denmark, small and medium-sized

businesses, government departments, local authorities,

hospitals, charities and NGOs.

In the academic, business and technical world Adept

Scientific is known for its efficiency and expertise in supplying

solutions essential for customers’ business requirements,

offering the highest level of support and back-up.

Millbrook Proving Ground LtdStation Lane

Millbrook

Bedfordshire

MK45 2JQ

UK

Tel: +44 (0)1525 404242

Fax: +44 (0)1525 403420

Email:neil.fulton@millbrook.co.uk

Website:www.millbrook.co.uk

Contact: Neil Fulton

Millbrook is one of Europe’s leading locations for the

development and demonstration of every type of land vehicle,

from motorcycles and passenger cars to heavy commercial,

military and off-road vehicles. Our custom-built facility

provides virtually every test, validation and Homologation

service necessary for today’s demanding programmes,

complemented by a worldwide reputation for confidentiality,

service and competitiveness.

We also engineer, develop and build low-volume service

vehicles, trial and evaluate vehicle capability, investigate in-

service failures and provide specialist Driver Training.

MIRA Limited

Watling Street

Nuneaton

Warwickshire

CV10 0TU

UK

Tel: +44 (0)247 635 5000

Fax: +44 (0)247 635 8000

Email: enquiries@mira.co.uk

Website: www.mira.co.uk

Contact: Kristy Thompson, Marketing Manager

MIRA is a highly customer-focused, world-class,

independent vehicle engineering consultancy, shaping

everything we do around the partnerships we create. We

harness the skills, experience and knowledge of our talented

experts to provide our customers with intelligent solutions

to their challenging problems. MIRA offers full system design,

test and integration expertise to the global automotive,

defence, rail and transport industries. MIRA’s technical

facilities provide a truly global centre of excellence from which

to innovate, engineer, test and implement market changing

solutions.

31

Research by the Younger Engineer

Are you just starting out on an engineering career or

currently studying for a postgraduate degree. Would

you like to tell us about your research? What is the hot

topic at the moment?

We have many industrial readers who would be

extremely interested in hearing about your research,

both what it involves and its background. Articles of up

to 850 words (approx 1 A4 page) can be published

under our new ‘Research of the Younger Engineer’ in

the journal, presenting a great opportunity to make

industry aware of your work.

Send your articles to the Editor:

Dr Karen Perkins

Materials Research Centre

School of Engineering

Swansea University

SA2 8PP

EIS 31 Inners v01.indd 31 22/9/11 15:47:24

News on Smart Materials and StructuresWelcome to our

co lumn on Smar t

Materials, with the

usual mix between

technical news and

forthcoming evens

in the field.

The MEMS industry

relies heavily upon

rare -ear th meta ls

(Neodymium, Yttrium, Gadolinium

for example). It is now a well know

fact that 97 % of rare earth metals

wor ldw ide a re p roduced in PR

China, and this situation generates

some concern about any possibility

of monopolising the market (“Put all

the eggs in a basket, but watch that

baske t ” , as popu la r w isdom

enunc ia tes) . A recent paper

produced by a team f rom the

University of Tokyo and published

in Nature Geosc ience (h t tp : / /

www.nature.com/ngeo/journal/v4/

n8/ful l /ngeo1185.html) describes

up to 78 sites, between 3000 and

6500 m below the South and North

Pacific surface. These sites could

provide up to one fifth of the world’s

consumpt ion o f ra re ear th

elements, definitely not a negligible

percentage. There are some strong

env i ronmenta l concerns about

mining rare earth minerals, both

above and below the sea. However,

considering the extremely strategic

role that these metals invest in our

techno logy, I wanted to g ive a

particular mention to this discovery.

Someth ing e lse tha t may be a

future game-changer for systems

and architectures for active control,

embedded sys tems and mode l

simulation is the new Intel Tri-gate

chip (ht tp: / /newsroom.intel .com/

docs /DOC-2032) , wh ich shou ld

al low to cont inue the val idi ty of

Moore’s law beyond the 22 nm and

14 nm processors ( the la t te r

currently considered as the limit for

in tegra t ion due to quantum

mechanics effects). Although this

transistor appears to have been

designed essentially to cut a big

slice of the market for tablets and

smar t phones (cur ren t l y

monopolised by ARM, a truly British

success story), i t is foreseeable

that the use of the chip will have

more than an appl icat ion, f rom

sensor systems with high through-

put bus data rates to h igh-end

design and s imulat ion sof tware

tools.

In the field of Structural Integrity, I

would like to highlight the recent

development of an opt ical f ibre

corrosion sensor based on l ight

reflection principles, and produced

by a team from the University of

Texas at Arlington. The design of

the sensor is based on an optical

fibre reflection device coupled to a

tube/film sub-assembly, formed by

welding a sacrificial metallic fi lm

to a steel tube. One side of the

sacrificial metallic film is polished

and isolated from the environment,

while the opposite side is exposed

to the corrosive environment. The

corrosion pits erode the sacrificial

film, and reduced the reflectivity of

the polished surface, which is then

detected by the fibre optics. The full

descr ip t ion o f th is in te res t ing

sensor has been recent ly

published in Smart Materials and

Structures

(IoP, http://iopscience.iop.org/0964

1726/20/8/085003/pdf/0964

1726_20_8_085003.pdf).

Another recent in te res t ing

development generated by a team

f rom Fraunhofer Ins t i tu te and

University Technical Darmstadt is

the use o f ac t ive p iezoe lec t r ic

pa tches to reduce c rack

propagation in aluminium plates

(h t tp : / / i opsc ience . iop .o rg /0964

1726/20/8/085009/pdf/0964

1726_20_8_085009.pdf). The main

idea behind the concept is to lower

the cyclic stress intensity factor

near the tip of the crack using low

voltage piezo actuators, decreasing

therefore signif icant ly the crack

growth ra te . The paper a lso

descr ibes a s tat is t ica l analys is

made on several test layouts, and

showing an average 20 % reduction

of crack propagation in the various

cases. A promising start for this

concept, and a very good piece of

work from the German team.

We look now a t a se lec t ion o f

incoming conferences in the area

of smart materials and structures.

For the aud ience in teres ted in

Structural Heal th Moni tor ing an

important event this year will be

SHM 2011 in Krakow (Poland: http:/

/en.shm2011.pl/). Embedded within

the conference there will be a short

course on St ruc tu ra l Hea l th

Mon i to r ing w i th p res t ig ious

speakers of the field. Preparations

are already underway for CIMTEC

2012 (4th International Conference

of Smart Materials and Systems,

Monteca t in i ( I ta ly : h t tp : / /

www.c imtec-congress.org/2012/

genera l_ou t l ine .asp) . The

conference has several paral le l

sessions, and promises to be one

of the t rue happen ings o f the

season in the smar t mater ia ls

field. For people having the chance

of travelling through India at the

beginning of next year, the Indian

Ins t i tu te o f Techno logy o f

Bangalore organises the 6th ISSS

Conference ( ISSS – 12: h t tp : / /

isssonline.in/isss-2012), which is

anticipated to be one of the major

events in Asia next year. Closer to

home is the ECCOMAS SMART’11

organised by Fraunhofer IZFP in

Saarbrücken (Germany – URL at

h t t p : / / w w w. i z f p . f r a u n h o f e r. d e /

smart11/).

Best wishes for a fruitful activity in

the months to come.

Fabrizio Scarpa

Professor of Smart Materials and

Structures, Bristol University

32EIS 31 Inners v01.indd 32 22/9/11 15:47:25

News from Formula Student

33

Institution to

host Ai r

C a p t u r e

Week to

demonstrate

key c l imate

c h a n g e

solution

T h e

Ins t i tu t ion o f Mechan ica l

Eng ineers w i l l be hos t ing “A i r

Capture Week” in October to raise

awareness amongst the publ ic,

pol icy makers and engineers of

one o f the most innova t ive

emerging technologies in the fight

against climate change.

The week long series of events,

which will start on 24 October, will

feature an international summit of

experts, workshops, discussions

and debates, as wel l as a l ive

public demonstration of air capture

technology. The latter will be given

by Professor Klaus Lackner from

Columbia University in front of a

London audience on the evening

of 26th October.

By using air capture machines to

remove CO2 from the air and then

storing it underground, it creates

negat ive emiss ions which help

reduce the concent ra t ion o f

g reenhouse gases in the

atmosphere.

CO2 captured by the devices could

also be used for carbon recycling,

where industries that require CO2

as a chemica l feeds tock fo r

mak ing p roduc ts such as

substitute fuels, source their CO2

from the atmosphere and thereby

es tab l i sh ‘ c losed ’ loops fo r

carbon.

Air capture technologies currently

provide a viable solution to historic

emissions produced in the last

century and di f f icul t to manage

emiss ions l i ke those f rom

aviat ion,shipping and dispersed

industries.

Fur thermore as in te rna t iona l

climate change negotiations stall

these technologies buy the world

t ime to get to grips with cutt ing

emissions produced.

Efforts to combat climate change

have largely and rightly focused on

mitigation – so cutting the amount

of greenhouse gas emiss ions,

particularly the CO2, we produce.

While work must continue to reach

a global agreement with ambitious

cuts to emissions, there is also a

real need for governments and

industry to look at creat ive and

ingen ious ways o f p revent ing

climate change by tackling difficult

emissions sources and taking out

the greenhouse gases we have

already put in the atmosphere –

essentially cleaning up air.

As will be demonstrated during the

Institution’s”Air Capture Week”, the

technology to make these CO2

absorb ing mach ines a l ready

ex is ts , bu t government and

bus inesses need to p r io r i t i se

funding in these technologies to

make them happen quickly and on

a b ig enough sca le to make a

difference.

The Ins t i tu t ion o f Mechan ica l

Eng ineers i s ca l l i ng on UK

Government to:

• support more detai led work to

establish the cost of air capture

technology and demonstrate i ts

feasibility;

• develop policy frameworks that

enable the adoption of negative

emissions and carbon recycl ing

approaches to mitigation; and

• provide international leadership

on negative emissions and carbon

recycling.

Wi th the lack o f in te rna t iona l

p rogress in the mi t iga t ion o f

climate change, there is an urgent

need fo r governments and

bus inesses to fund techno logy

development and to accept that air

capture is a key part of the solution

to the b igger c l imate change

problem.

Dr Tim Fox

Head of Energy and Environment

at the Institution of Mechanical

Engineers

Instrumentation, Analysis and Testing Exhibition

Tuesday, 6 March 2012

10:00 - 16:00

Silverstone Race Track

International Exhibition Centre

Diary of Events

EIS 31 Inners v01.indd 33 22/9/11 15:47:25

Challenge to Improve the Process from design to productThis article is intended

to stimulate a debate on

a subject frequently

discussed but rarely

addressed. Within

organisations each

technology section is

driven by its own

objectives but the

c o m m u n i c a t i o n

between sections is

generally nobodies responsibility.

Our process from design through

prediction test and production needs

to improve if we are to realise the

demands of product improvement in

shorter time and lower cost whilst

ensuring product life and warranty.

The challenge is to achieve the

following targets and for Managements

to accept the need for the required

organisation to:-

1. Improve and validate predictive

models.

2. Use simpler materials with lower

manufacturing sensitivity.

3. Reduce test time and power

consumed by 50%.

4. Maintain or increase product fatigue

life.

5. Optimise and monitor

manufacturing effects on fatigue.

6. Reduce time to market.

Technologies used in the complete

process appear to have become

increasingly isolated and whilst they

have improved their own process the

transfer of data between has remained

historic and limited.

1. Improve and validate predictive

models

Predictions often use inappropriate

material data. Materials are now offered

that suggest improved life but frequently

suffer from the difficulty of maintaining

their advantageous properties through

the manufacturing process. The quality

control material inspection generally

only provides information based on

static values of a sample which has

not been stabilised and has unknown

residuals. Testing has shown that

material from different suppliers all to

the same specification and passed

goods inward inspection had a

difference in fatigue results of 5 to 1.

2. Use simpler materials with lower

manufacturing sensitivity

The manufacturing process is

significant in creating the final material

condition in the component and yet few

if any measurements are made to

identify manufacturing changes which

control and improve component life.

When components are formed and

welded significant changes to these

properties almost always take place.

The degree of work done in the forming

process and the distributed thermal

changes in the welding process can

result in significant residual strain

variations.

A 3 to 1 life variation caused by an

uncontrolled cooling process after

welding creating residual strain from

thermal gradients.

3. Reduce test time and power

consumed by 50%

Frequently information provided for a

test is a load profile to be applied. The

anticipated deflections at the loading

points should be provided but often are

not. These deflections fix the flow,

response and power requirements of

the servo hydraulic actuators of the test

rig. Often the limitations of the rig are

not identified until the rig is built. With a

complete set of initial information the

rig limitations can be identified and

addressed. Modifications to reduce test

time and power and give a repeatable

test with the available equipment can

be proposed. Slowing down the fewer

high velocity amplitudes and speeding

up the many lower velocity amplitudes

can significantly reduce test time whilst

applying the same profiles. Test times

are frequently reduced by a factor of 4

and in many cases a factor of 8. The

test takes 12% to 25% of the original

time and uses less power.

4. Maintain or increase product life

Difference in residual strain in received

material can be significant. Flat steel

sheet is bent straight to meet flatness

specifications. This has the potential

to create wide variation within the sheet

of residual strain.

When components are formed and

welded significant changes to these

properties almost always take place.

The degree of work done in the forming

process and the distributed thermal

changes in the welding process can

result in significant residual strain

variations. Control and manipulation of

induced residuals has shown 3 to 1

life improvement.

5. Optimise and reduce

manufacturing effects of fatigue

Test reports generally give arrangement

definitions and life as a cycle count with

details of failure location if appropriate.

If no failure occurs little or no information

is provided as to how much life was

still in the component. It is generally an

assumption that the test carried out did

have the load distribution of the

predictive model. Techniques are

available which give 3 D strain

distributions of the component under

test providing overlay files for model

validation. These show actual load path

and real deflections.

Huge differences between the

predicted and achieved are apparent

when unlike data is compared.

Incorrect changes in design can result

from this non validated process.

6. Reduce time to market

By applying these techniques and

continually updating and validating

each stage of the process with real

information significant changes can be

made in time to market for a new

product. It is important to develop the

complete product process based on

measured and improved data instead

of a comparative evaluation based on

previous units.

Discussion

The communication between

technologies needs to be improved

and techniques, which are available

34EIS 31 Inners v01.indd 34 22/9/11 15:47:25

BS 8888:2011

Later this year, a new

revision of BS 8888 will

appear, which will be the

most significant update

since the standard was

first published in 2000.

The year 2000 was

when the British Standards Institution

(BSI) withdrew BS 308, the UK’s

national standard for engineering

drawing, and adopted instead the

international system for technical

specifications which is defined in ISO

standards.

This international system for technical

product specification is known as

Geometrical Product Specification (ISO

GPS). It is defined in a range of

interlinked ISO standards, and has

been adopted throughout Europe, and

also by many other countries across

the globe. In fact, the only alternative in

widespread use is the American system

of geometric dimensioning and

tolerancing which is defined in the

ASME Y14.5 standard.

When the UK adopted the ISO GPS

system, BSI also published a new

standard, BS 8888, which was intended

to ease and simplify the transition from

BS 308 to the ISO GPS system.

BS 8888 has since been revised and

up-dated several times, to keep

abreast of developments and changes

within the ISO GPS system.

News from British StandardsBS 8888 was always conceived of as a

‘signpost’ document, which would

guide people through the ISO system,

and provide some explanation about

how to work with it. In large part it is an

index, which is essential if users are to

find information amongst the large

number of ISO standards that

constitute the ISO GPS system.

Despite this, it is still often difficult to

work with a system which is dispersed

across a wide range of different

standards, and although there is some

structure to the way in which these

documents are organised and inter-

relate, it is still somewhat haphazard

in many areas.

When this is coupled with the fact that

the ISO GPS system is continuing to

expand, with the development of many

new capabilities for the definition of

technical requirements, in ever

increasing detail, there are clearly going

to be challenges for anyone attempting

to work with it.

In an attempt to address these

challenges, the next revision of BS

8888, due for publication towards the

end of 2011, is going to incorporate a

substantial amount of technical content

which has been brought across from

some of the key ISO standards. The

aim is to provide the basic elements of

technical product specification, and ISO

GPS, in a single document. This will

not replace the ISO standards, which

will still be referenced from within the

British Standard, and will provide more

extensive and more detailed content,

but it should mean that the most

fundamental elements of the system

will be gathered together in a more

accessible format.

The document will be split into two

sections, the first for Technical Product

Documentation, and the second for

Geometrical Product Specification. The

first section will cover the manner in

which information is presented, such

as the layout of drawing sheets,

projections, format of dimensions and

tolerances, representation of features,

etc. The second section will deal with

how products are specified, with the

use of datums, geometrical tolerances,

surface texture requirements etc.

At the time of writing this, an early draft

is being published by BSI for public

comment and feedback, although there

is still further detail to be added, and

some further changes to be made,

before final publication. If you read this

in time, you will be able to have a look

at the draft document, and pass on any

comments or feedback (BSI publishes

draft standards for comment at http://

drafts.bsigroup.com/).

Iain Macleod

Iain Macleod Associates

and Chair of BSI technical committee

TDW/4/8 which is responsible for the

maintenance and development of BS

8888.

employed to control and validate each

stage of the process.

The global market demands less

sophisticated and more economic

controlled materials which are less

vulnerable to the manufacturing

process.

Cost and time of each step of the

process has to be reduced and our

predictive modelling capability

improved by validation that include

controlled production processes.

The technologies are available and

mature.

The problem is that there is no

organisational responsibility for the

improvement of information between

technologies. Techniques are not seen

within one technology area as being

their responsibility.

I look forward to your comments.

Norman Thornton

Engineering Consultant

Continued from previous page

35EIS 31 Inners v01.indd 35 22/9/11 15:47:26

In the last issue of the Journal I

contributed a column on Open Access

technical information. I also promised

a short series about large-scale

changes which are taking place in

publishing practices. Here is the

second.

The first article was about institution

repositories, and how this has made a

difference to accessing research

information. Alongside these changes

similar ones have been occurring in

availability of teaching material. A

development which was initially called

Open Courseware (OCW), and is now

usually called Open Educational

Resources (OER), has made much

teaching material freely available in all

subjects. Downloading is immediate

and copyright is usually a Creative

Commons License. If you want to know

more about this sort of License look

up my article in this journal (reference

below). Briefly it means that you can do

what you like with the information as

long as you say where it came from

and don’t use it to earn money.

You may not be involved in education,

but some OER material may still be

useful to you. For example, the UK

Open University have released many

of their courses under Creative

Commons Licences, using the

heading OpenLearn. They list 36

courses under Engineering and

Technology, 29 under Computing and

ICT, and 38 under Business and

Management. I have known for some

time that there was an OpenLearn

course called “Finding Information in

Engineering and Technology”. Recently

I needed to read another one called

“Finding Information in Business and

Management”. As I started this article I

had a closer look and discovered

‘Finding Information in’ Computing and

ICT, Arts and History, Education, Health

and Lifestyle, Modern Languages,

Mathematics, Science and Nature, and

Society. Many us spend time searching

for information these days. Perhaps these

free courses might be worth a look.

All ten of the courses have the same

framework, with bolted-on bits to suit

each subject. You will probably be able

to skip the starting questionnaire about

how competent you are already. You will

also know how to use keywords, but

the section about how to systematically

build a keyword list for a serious search

may sharpen your performance. You

probably use a general search engine

like Google, but the courses list many

more sources under various headings.

Taking the Engineering and Technology

one, the list is:

Search engines; Google, Yahoo!,

AltaVista, Ask.com, Google Scholar.

Subject gateways (Directories)

BUBL, Intute, TechExtra,

Books and electronic books

WorldCat.

Databases ROUTES, Recent

Advances in Manufacturing, TRIS

Online.

Images Arts and Humanities Data

Service, British Library Picture

Library.

Journals Directory of Open Access

Journals (plus some advice on

general journal searching).

Encyclopedias Wikipedia, Encarta.

Patents Esp@cenet, UK Patents

Office, World Intellectual Property

Organisation.

News sources EureaAlert, Abyz

News Links

A description is given of the

characteristics of each source. At the

end of the list is a section giving five

questions to help you decide whether

a particular source is right for your task.

The modules I have used then go on to

a section about checking whether the

information found is of good quality.

Most of us know that much of the

information on the internet is unreliable.

If reliability is important an approach

called PROMPT is recommended. This

suggests checking six qualities. These

are:

• Presentation (is it easy and

pleasant to read)

• Relevance (whether it is what you

want)

• Objectivity (it should be objective,

that is not biased)

• Method (how was the information

obtained)

• Provenance (who published it, how

qualified are they)

• Timeliness (is it old or recent)

There are about 200 words of text for

each of the six points, giving guidance

about what to look for.

Information produced by searches will

normally be stored on a hard disk. Your

space on this disk will have your files,

usually separated into folders or other

divisions. Organising these so that you

can get the one you want when you want

it can be a problem. If you are using

Microsoft Windows this has a ‘Find’

command, but this can be slow. The

courses point out that a faster

alternative is a desktop search tool

such as:

• Ask

• Copernic

• Google Desktop

• Windows Live Toolbar

• Yahoo! Desktop Search

These also offer more ways of

organising the files.

Many other facilities are provided on a

computer equipped for office use. Alerts

can be set to give regular notice of new

information, groups can be joined, RSS

feeds can be used and so on. These

are all described in the courses.

Reference Sherratt, Frank “Free

teaching information: what does it

mean for companies?” Engineering

Integrity, Vol. 21, March 2007, pp 26-30

Frank Sherratt, Engineering

Consultant

“Open Access”, another instalment

36EIS 31 Inners v01.indd 36 22/9/11 15:47:26

Group News

Simulation, Test

& Measurement

Group

The Instrumentation

Analysis and Testing

Exhibition held at

Silverstone in March

this year drew an all time record high

of exhibitors, attendees and income for

the EIS. Against a backdrop of

shrinking and cancelled exhibitions

across the UK and across Europe, the

EIS is clearly growing well and

providing what the many other events

lack.

We are building on our success this

year and, just as we outgrow the Jimmy

Brown Centre at Silverstone, they kindly

built us a massive new Exhibition area,

which opened a few months ago. It will

provide us far more space and

maintains our now familiar view over

the start-finish line – which was also

moved.

The Open Forum we held during the

exhibition on 4 & 7 Poster testing

attracted a guest panel covering

production, military and motorsport

speakers and attendees from wider

industries still. Our particular thanks

to Colin Dodds for chairing with his

contagious humour, mixed perfectly

with his own experience and

knowledge. The single forum event will

be increased and cover : KERS, Vision

and Lasers, CAE Testing, Electric

Actuation, Data Protocols, Acoustic

Emission and Vehicle Simulators. If

you have some sound experience and

would like to be on the guest panel for

any of these or even ask questions for

the floor, we would love to hear from

you. The whole exhibition will again be

in early March (6th) and include a wide

range of exhibitors, presentations,

workshops and the forums, so it’s a

useful day away from your PC’s and

meetings. As always you are

guaranteed EIS hospitality,

refreshments and will invariably meet

up with many people you haven’t seen

for a while.

The STMG would like to thank Peter

Blackmore for chairing the EIS for so

many years. The EIS was recently

described to me as the who’s-who in

the world of Fatigue and Testing. To

everyone who’s met him Peter clearly

epitomises the uniqueness and quality

of characters in the EIS.

Conway Young

Chairman

Sound &

Vibration

Product

Perception

Group

The last event that the SVPP held was

a one-day seminar on 29th March 2011

entitled ‘Low Carbon Transportation in

New Sound Environments’. As with the

previous event in Dec 2009, it was a

joint event with Warwick Innovative

Research Centre, held at their Digital

Suite within the University of Warwick

campus.

Thanks to an outstanding effort by the

committee, a very interesting

programme was organised, including

three presenters from Germany.

Despite the challenging economic

situation a total of 44 delegates

attended, which met our expectation.

One welcome addition was the

attendance of two Warwick University

student groups who show-cased their

projects in the exhibition area, and

attended some of the presentations.

One of these groups showed their

research on which type of sounds could

be emitted from EVs as pedestrian

warnings, having developed their own

sound synthesis software and

hardware, which they demonstrated at

the event using mobility scooters. The

other group showed their work on an

ultra light-weight speaker system using

a foil laminate which can be formed to

a shape suitable for mounting in a

vehicle facia area. We were very

pleased to have the student

participation as it satisfies one of the

key EIS objectives - to get young

engineers engaged with EIS and its

events. We will plan to do this again at

the next event.

The seminar finished with an expert

panel session, where most of the

presenters were joined by other experts

to answer questions from the audience

in the style of BBC ‘Question Time’. A

very wide range of questions were put

to the panel, ranging from emerging

technology to new environmental

legislation, and each member of the

panel in turn gave their views. This has

now become a regular feature of the

SVPP events as it is not only highly

informative (and entertaining!), but also

seems to hold most of the delegates

until a much later time of day (due to

the quantity of good questions and

comprehensive answers we actually

finished at 5.00 even though timetabled

for 4.30!). At some past events, people

have started slipping away from mid-

afternoon, which can leave a rather

sparse lecture theatre for the

concluding address!

The committee is now in the early

stages of planning the next one-day

event to be held in early May 2012, once

again a joint event with WIMRC at the

their venue, and we expect soon to be

publishing a call for papers on a topical

sound and vibration product perception

subject.

John Wilkinson

Chairman

37EIS 31 Inners v01.indd 37 22/9/11 15:47:27

President: Peter Watson O.B.E.

Committee members

Acting Chairman

Trevor Margereson, Engineering Consultant ............................................................................................... 07881 802410

Vice Chairman

Robert Cawte, HBM United Kingdom .......................................................................................................... 0121 733 1837

Treasurer

Khaled Owais, TRaC Environmental & Analysis .......................................................................................... 01926 478614

Company Secretary

Robert Cawte, HBM United Kingdom .......................................................................................................... 0121 733 1837

EIS Secretariat

Lisa Mansfield ............................................................................................................................................... 02476 730126

Communications Sub Committee – ‘Engineering Integrity’ Journal of the EIS

Honorary Editor

Karen Perkins, Swansea University ............................................................................................................. 01792 295666

Managing Editor

Catherine Pinder ........................................................................................................................................... 07979 270998

Durability & Fatigue GroupChairman

Robert Cawte, HBM United Kingdom .......................................................................................................... 0121 733 1837

Secretary

Khaled Owais, TRaC Environmental & Analysis .......................................................................................... 01926 478614

Members

John Atkinson, Sheffield Hallam University .................................................................................................. 0114 2252014

Martin Bache, Swansea University ................................................................................................................ 01792 295287

Peter Blackmore, Jaguar Land Rover ........................................................................................................... 01926 646757

Feargal Brennan, Cranfield University .......................................................................................................... 01234 758249

Emanuele Cannizzaro, Atkins Aerospace ..................................................................................................... 01454 284242

Amirebrahim Chahardehi, Cranfield University ............................................................................................ 01234 754631

John Draper, Safe Technology ..................................................................................................................... 0114 255 5919

Steve Hughes, Bodycote ............................................................................................................................... 01524 841070

Karl Johnson, Zwick Roell Group ................................................................................................................. 0777957 8913

Davood Sarchamy, British Aerospace Airbus ................................................................................................. 0117 936 861

Giora Shatil, Darwind ........................................................................................................................... +31 (0)30 6623987Frank Sherratt, Engineering Consultant ....................................................................................................... 01788 832059

James Trainor, TRW Conekt Engineering Services ................................................................................... 0121 627 4244

John Yates, University of Sheffield ............................................................................................................... 0114 222 7748

Sound & Vibration Product Perception Group

Acting Chairman

John Wilkinson, Millbrook Proving Ground ................................................................................................... 01525 408239

Members

Marco Ajovalasit, Brunel University ............................................................................................................... 01895 267 134

Alan Bennetts, Bay Systems ......................................................................................................................... 01458 860393

Dave Boast, Avon Rubber .............................................................................................................................. 01373 863064

Mark Burnett, MIRA ......................................................................................................................................... 02476 355329

Peter Clark, Proscon Environmental ............................................................................................................. 01489 891853

Gary Dunne, Jaguar Land Rover ...................................................................................................................02476 206573

38EIS 31 Inners v01.indd 38 22/9/11 15:47:27

Henrietta Howarth, Southampton University ................................................................................... 023 8059 4963/2277

Paul Jennings, Warwick University ..............................................................................................................02476 523646

Rick Johnson, Sound & Vibration Technology .............................................................................................01525 408502

Chris Knowles, JCB .................................................................................................................................... 01889 59 3900

Colin Mercer, Prosig ...................................................................................................................................... 01329 239925

Jon Richards, Honda UK ..............................................................................................................................01793 417238

Nick Pattie, Ford ....................................................................................................................................................................

Simulation, Test & Measurement Group

Chairman

Conway Young, Tiab .....................................................................................................................................01295 714046

Members

Paul Armstrong, Amber Instruments ............................................................................................................. 01246 260250

Ian Bell, National Instruments ......................................................................................................................01635 572409

Steve Coe, Data Physics (UK) .......................................................................................................................01323 846464

Colin Dodds, Dodds & Associates ............................................................................................................... 07880 554590

Dave Ensor, MIRA .......................................................................................................................................... 02476 355295

Graham Hemmings, Engineering Consultant ............................................................................................ 0121 520 3838

Neil Hay, Napier University ........................................................................................................................... 0131 455 2200

Richard Hobson, Serco Technical & Assurance Services ............................................................................ 01332 263534

Trevor Margereson, Engineering Consultant ............................................................................................... 07881 802410

Ray Pountney, Engineering Consultant ........................................................................................................ 01245 320751

Tim Powell, MTS Systems ............................................................................................................................ 01285 648800

Mike Reeves, Engineering Consultant ......................................................................................................... 01189 691870

Gordon Reid, Engineering Consultant .........................................................................................................01634 230400

Nick Richardson, Servotest ...........................................................................................................................01784 274428

Paul Roberts, HBM United Kingdom ............................................................................................................0785 2945988

Jarek Rosinski, Transmission Dynamics .................................................................................................... 0191 5800058

Geoff Rowlands, Product Life Associates ....................................................................................................01543 304233

Frank Sherratt, Engineering Consultant ....................................................................................................... 01788 832059

Bernard Steeples, Engineering Consultant .................................................................................................. 01621 828312

Marcus Teague, LDS Test & Measurement ................................................................................................. 01763 255 255

Norman Thornton, Engineering Consultant ................................................................................................. 07866 815200

Jeremy Yarnall, Consultant Engineer ........................................................................................................... 01332 875450

SponsorsThe following companies are SPONSORS of the Engineering Integrity Society. We thank them for their continued support

which helps the Society to run its wide-ranging events throughout the year.

Adept Scientific

AWE Aldermaston

Bruel & Kjaer

Datron Technology

Doosan Babcock

HBM United Kingdom

Instron

Kemo

Kistler Instrumemts

LMS UK

Millbrook Proving Ground

MIRA

MOOG

National Instruments

Polytec

Rutherford Appleton Laboratory

ServoTest

Techni Measure

TRaC Environmental & Analysis

Transmissions Dynamics

39EIS 31 Inners v01.indd 39 22/9/11 15:47:28

Intensive short courses for engineers working inenvironmental testing and those concerned withdesign assurance, reliability and type approvaltesting, product development and screening.

VIBRATION TESTING18 – 19 January 2012

CLIMATIC TESTING15 – 16 February 2012

PRACTICAL SIGNAL PROCESSING21 – 22 March 2012

MECHANICAL SHOCK TESTING19 April 2012

Further information from:Andy Tomlinson, CPD Dynamics Ltd.

andy@cpd-dynamics.co.ukwww.cpd-dynamics.co.uk

CPDdynamics

2012 SHORT COURSES

EIS 31 Inners v01.indd 40 22/9/11 15:47:30

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