DESIGN AND ANALYSIS AND OPTIMISATION OF VEHICLE

B-PILLAR

MODULE LEADER- MARTIN LANDER

REPORT SUBMITTED BY

IMRAN SHIHABUDEEN RAJELA

5914621

Contents 1. SUMMARY ........................................................................................................................................... 5

2. INTRODUCTION ................................................................................................................................... 6

2.1 Aim ................................................................................................................................................ 6

3. EEVC & Euro NCAP .............................................................................................................................. 6

3.1 Side Impact Test ............................................................................................................................ 7

4. LOAD CASE ANALYSIS (B – PILLAR) ...................................................................................................... 7

4.1 Material Selection ......................................................................................................................... 7

4.2 Bending moment of the beam ...................................................................................................... 8

4.3 Stress acting on a beam ................................................................................................................ 9

4.3.1 Von Mises’s Stresses .............................................................................................................. 9

4.4 Finite Element Analysis (FEA) ...................................................................................................... 10

4.4.1 Meshing and Mesh Considerations in CATIA ....................................................................... 10

4.4.2 Absolute SAG and Proportional SAG .................................................................................... 12

5. DISCUSSIONS ..................................................................................................................................... 12

5.1 Critical factors affecting the performance of B-Pillar ................................................................. 12

5.1.1 Dimension of B-pillar ............................................................................................................ 12

5.1.2 Location of restraints ........................................................................................................... 13

5.1.3 B-pillar Architecture ............................................................................................................. 13

5.1.4 Second Moment of Area ...................................................................................................... 14

5.1.5 Existing B-pillar design ......................................................................................................... 14

5.1.6 Factor of safety: ................................................................................................................... 15

6. DEVELOPMENT OF IDEA .................................................................................................................... 15

6.1 Initial idea .................................................................................................................................... 16

7. FINAL DESIGN MODIFICATION .......................................................................................................... 17

7.1 Manufacturability of the reinforcement ..................................................................................... 18

8. ANALYSIS OF LOAD CASE DUE TO REINFORCEMENT ........................................................................ 18

9. 2D CAD DRAWING ............................................................................................................................. 19

9.1 Reinforced B-Pillar ...................................................................................................................... 19

9.2 Reinforcement ............................................................................................................................ 20

9.3 Primary Reinforcement ............................................................................................................... 20

9.4 Secondary Reinforcement ........................................................................................................... 21

9.5 Exploded View ............................................................................................................................. 22

10. CONCLUSION AND RECOMMENDATION......................................................................................... 22

10.1 Conclusions ............................................................................................................................... 22

10.2 Recommendations .................................................................................................................... 22

10. 3 Limitations of FEA solver .......................................................................................................... 23

11. REFERENCE ...................................................................................................................................... 23

12. APPENDIX ........................................................................................................................................ 24

Catia Report Generation: ..................................................................... Error! Bookmark not defined.

Table of Figures:

Figure 1: B – Pillar (Smitty, 2012) ....................................................................... 6

Figure 2Euro NCAP Mobile Deformable Barrier Side Impact Test at 50 km/h the

vehicle side b pillar and other body parts. (Hobbs & Donough, 2006) ............... 7

Figure 3 bending momentum diagram ............................................................... 9

Figure 4: Mesh Skewness(Bakker, 2006) .......................................................... 10

Figure 5: Mesh Smoothness (Bakker, 2006) ..................................................... 11

Figure 6: Mesh Aspect Ratio (Bakker, 2006) ..................................................... 11

Figure 7: Meshing of B-Pillar (CATIA, 2014) ...................................................... 11

Figure 8: absolute sag. ..................................................................................... 12

Figure 9 Bending momentum and diflection equation ..................................... 12

Figure 10 clamping on B-pillar .......................................................................... 13

Figure 11 types of reinforcement and structure .............................................. 13

Figure 12 equations for calculation of second moment of inertia of I, T and C

section ............................................................................................................. 14

Figure 13 B-pillar side and sectional view ........................................................ 15

Figure 14 B-pillar analysis ................................................................................ 16

Figure 15 initial design and analysis ................................................................. 17

Figure 16 final design von Mises ...................................................................... 18

Figure 17 mass of reinforced b pillar ................................................................ 18

Figure 18: Isometric view of reinforced B-pillar ............................................... 19

Figure 19: B-pillar Drafting ............................................................................... 20

Figure 20: Primary reinforcement drafting....................................................... 20

Figure 21: secondary Reinforcement Drafting .................................................. 21

Figure 22: Exploded view Drafting ................................................................... 22

1. SUMMARY

This technical report is the representation of the study carried out on a car B–pillar for optimising it

under the given condition by performing a load case analysis on the component using an FEA solver.

It also represents my knowledge in surface designing along with my knowledge in finite element

analysis. The given design is modified without changing its basic outer structure to bring it optimised

under the given load case, with a desirable deformation under the required mass limit. The design is

generated under the consideration of real time business scenarios such as, material, mass,

manufacturability and time. The impact of reinforcement, types of reinforcements, effect of change

in geometry and material properties of reinforcement are also discoursed in this work. A detail

description of the software used and the steps followed to generating the design and for analysing is

also explained in this work. The report discourse the stages in developing idea and modifications

made to get an optimised result. The 2-D CAD drawings of the final design are drawn considering

BS8888 to give the clarity of design. The limitation of FEA solver and the assumption made for the

analysis process are also discussed in the report for future development.

2. INTRODUCTION

A B–pillar is a structure that is seen on the two sides of the car, which is held by the roof rail and the

bottom rail of a vehicle frame. It acts as a rigid support for the body frame to resist the forces acting

on the vehicle due to side impact and in case of roll-over of the vehicle. The B-pillar is provided with

reinforcement to reduce the deformation due to side impact force. The optimal design of the

reinforcement is made by the consideration of deformation limit, thickness of material used and the

load subjected on it. It should be lighter and also should absorb the impact load with lesser

deformation. Many research studies are still going on in the development of b pillar, to improve its

performance by limiting the material, weight and cost of production with an ease of manufacturing

at a lesser time. A typical B–pillar is as seen in the image below.

Figure 1: B – Pillar (Smitty, 2012)

2.1 Aim The primary aim of this report work is to demonstrate my knowledge about vehicle structures,

surfacing using parameters, and different tool in CATIA and re-design the B-pillar with a

reinforcement which is optimised with-in the design parameters, structural constraints, and mass

constraint provided by the Euro NCAP and FMVSS for the structural safety of a new car. The new

vehicle standards of Euro NCAP state that the roof of the vehicle should support twice the load of

the vehicle without occupant. Also, the B-pillar should be under the elastic limit and should not

exceed a maximum deformation rang of above 40mm; considering the weight to be a major vehicle

performance factor.

3. EEVC & Euro NCAP

European Enhanced Vehicle safety Committee (EEVC) is an organisation that assigns the safety

limits of the vehicle and its components. It is been developed for the passive safety of the vehicle

occupant. An artificial collision testing environment is created for analysing the safety limits of the

vehicle. The vehicle body is fitted with several accelerometer sensors is used to determine the

impact strength and the deformation caused by that impact on the vehicle structure. Without the

approval of the EECV, the car body design is not considered safer for the real time accidents.

European new car assessment programme (Euro NCAP) is developed to provide a fair, meaningful

and objective assessment for the safety performance of cars. It is indented to inform consumers, as

well as the manufacturers about the safety performance of their car and giving credit to those who

provide maximum protection. The impact tests are based on those developed for legislation by the

European Enhanced Vehicle safety Committee (EEVC) for frontal and side impact protection of car

occupants.

3.1 Side Impact Test It is the test carried out by the Euro NCAP to determine the safety credentials of a vehicle when

subjected to a side impact load. The impact test is carried out is of two type; pole side impact test

and barrier side impact test. In the test the car is impacted on the driver’s door side by a 950 kg

Mobile Deformable Barrier (MDB), at 50 km/h. This test is used to determine the impact strength

and deformation caused on t

Figure 2: Euro NCAP Mobile Deformable Barrier Side Impact Test at 50 km/h the vehicle side b pillar and other body parts. (Hobbs & Donough, 2006)

4. LOAD CASE ANALYSIS (B – PILLAR)

For the optimisation of B-pillar, it was necessary to understand the load case, structural and material

properties and its limitations. For this a detailed study of the vehicle B-pillar is carried out to analyse

presently used methodologies in selecting materials for the B pillar and reinforcement,

reinforcement types, structures, manufacturability, time consumption cost effectiveness etc.

4.1 Material Selection Performance relays as the major factor on designing a product, structural stability at a lesser weight

with easy to manufacture is given more priority than simply concentrating on the basic requirement.

For the B-pillar, light weight structure with higher strength and lesser material and fewer welds will

be more desirable for the easy manufacturing. High Strength steel is structurally rigid, and is flexible

under elastic limit. It is cheaper and easy to cut join and weld.

For B pillar the material assigned was CP Steel 800/1000. The maximum allowable thickness was of

about 1.4 mm. And for reinforcement the material selected was High Alloy Steel. And maximum

allowable thickness was about 2 mm

Components

Maximum Thickness (mm)

Material

De

nsi

ty

(kg/

m3 )

Yo

un

g's

Mo

du

lus

(GP

a)

Yie

ld

Stre

ngt

h

(MP

a)

Ten

sile

stre

ngt

h

(MP

a)

Po

isso

n's

rati

o

B-pillar 1.4 CP Steel 800/1000

7850 210 800 1000 0.3

Reinforcements 2.0 High Alloy Steel

7850 210 1500 1700 0.3

Table : geometrical Constrains and Physical Properties

Load acting on sides of B-pillar = 140 kN

Maximum deformation of B-pillar = 40 mm

Combined mass of B-pillar and reinforcement = < 6kgs

Material under elastic limit

For the initial analysis, the B-pillar is considered as rigidly supported beam with a uniformly

distributed load. The assumption of uniformly distributed load is considered for the ease of hand

calculation.

4.2 Bending moment of the beam Bending moment is the reaction of a structural element when an external force or moment is given

to the element which causes bending of the element.

Bending moment relays on the length of the beam and applied force. The following figure illustrate

the bending moment of a rigidly supported beam with uniformly distributed force.

Figure 3 bending momentum diagram

4.3 Stress acting on a beam The stress is an important factor which determines the durability of a structure. It is an internal force

which is exerted on the neighbouring particles when subjected to an external force on outer surface.

A beam is a body which is subjected to shear stress. The shear stress of the beam is mainly

determined based the area of the beam where the force is concentrated on.

𝑆ℎ𝑒𝑎𝑟 𝑆𝑡𝑟𝑒𝑠𝑠 =force

Area

In the given B-pillar, the area near by the roof end is lesser compared to area near by the bottom

rail. Therefore, the stress distribution will be maximum at the less area region.

The stress at any point of the B-pillar can be determined by the formula.

4.3.1 Von Mises’s Stresses

Von Mises stress or equivalent tensile stress, is a scalar stress value which can be generated from

the Cauchy stress tensor. The Von Mises Theory, states that, a material is said to start yielding when

its von Mises stress reaches a critical value known as the yield strength. The von Mises stress is used

to determine the yielding of materials under any loading condition from results provided by simple

uniaxial tensile tests. The von Mises stress satisfies the property that two stress states with equal

distortion energy have equal von Mises stress. In a uniaxial tensile test, the principle stress in the

yield stress and the distortion energy density associated with it is given by;

𝑈𝑑 = 1 + 𝑣

3𝐸𝜎𝑌

2

Where; Ud is the distortion energy density, σY is the yield stress, E is the young's modulus, and 𝑣 is

the shear strain.

W is the load,

Z is modulus of cross section of the beam

l is length of beam

x is the distance of the point.

4.4 Finite Element Analysis (FEA) FEA is the mathematical method used to analyse the properties of a substance. It generate a

matrixes of finite number of elements and a splits the applied components to finite no of small areas

the applied properties to the materials are thus subjected to all these areas with continuous

reference. The advantage of FEA is that, it can provide the details of material property at any point

of material. It used finite number of nodes and elements to generate meshes to form uniform area

and compute the results for each of those unit areas.

4.4.1 Meshing and Mesh Considerations in CATIA

Meshing are the connections made between each nodes to form elements. The meshing splits the

entire area of the material to a number of unit areas. These areas are subjected to the applied

properties. Meshing varies based on the shape and structure of the material. For surface, 2D

meshing is used; whereas for SOLID, 3D meshing properties are used. In CATIA 2D meshing is done

using ‘OCTREE Triangle Mesher' and for 3D 'OCTREE tetrahedron Mesher' is used.

There are various mesh cell types that are used in FEA. The commonly used mesh types are;

Tri mesh – mesh between nodes form elements of closed triangular structure.

Quad mesh – mesh between nodes to form elements of closed rectangular structure.

Hex mesh – mesh between nodes to form elements of closed hexahedral structure.

Another factor to be considered while meshing is the mesh quality. There are three kinds of mesh

quality, these are;

Skewness

Smoothness

Aspect Ratio

An ideal triangular mesh cell would be an equilateral triangle however; this will obviously vary based

on the shape and structure of the component. The leaner connection propertied at edges and weld

joint, will generate Skewness nearby those areas.

Figure 4: Mesh Skewness(Bakker, 2006)

While meshing, generally the mesh formed will be uniform at the main surface and changes

gradually when moves to edges. Smoothness of meshing basically meant for the gradual change in

size of the mesh while approaching the limiting areas

Figure 5: Mesh Smoothness (Bakker, 2006)

All messes are assigned based on a particular aspect ratios. The aspect ratio provides ratio of the

longest edge length to that of the shortest edge length. In an ideal case it would be equal to 1. Based

on the aspect ratio the calculation time is determined. (For an equilateral triangle) (Bakker, 2006).

Figure 6: Mesh Aspect Ratio (Bakker, 2006)

While using generative structural analysis in CATIA, the meshing is generated using the ‘OCTREE

Triangle Mesher'. This is done because the B pillar and reinforcement designed is limited to analyse

using surfaces and thus it is considered as 2D bodies.

While meshing, when considering mesh size, the appropriate method to progress is by starting with

a relatively larger mesh size and gradually reducing the mesh size until a more accurate solution is

achieved. This will reduce the time for each and every analysis. However, if it is a larger assembly, it

may prove to be more time consuming. The reason being, the time taken to analyse the component

can range from minutes to hours depending on the mesh size and processing speed of the computer

used.

The figure below shows the mesh conditions applied to the B-pillar .CATPart file that was provided.

Figure 7: Meshing of B-Pillar (CATIA, 2014)

4.4.2 Absolute SAG and Proportional SAG

Absolute Sag is the maximum gap between the mesh and the geometry. It provide sag constraints

while meshing the edges.

Proportional Sag is the ratio between the local absolute sag and the local mesh edge length.

Absolut sag and proportional sag can modify the meshing’s at the edges.

Proportional sag value= (local Absolute sag value) / (local mesh edge length value)

Figure 8: absolute sag.

5. DISCUSSIONS

5.1 Critical factors affecting the performance of B-Pillar There are many factors which are responsible for the performance of B-Pillar. It is essential to

understand them deeply before assigning the design for reinforcement.

5.1.1 Dimension of B-pillar

The dimensions are one of the most important parts of engineering designing. It is essential to

provide the right dimension for the B-pillar as well as the reinforcement. The length and height of

the car is one of the major facts which determine the lateral strength of the vehicle the bending

moment of the B pillar is directly proportional to its length. This is been derived from the bending

moment of rigidly supported beam. Also, the shear stress acting on the beam surface is in directly

proportional to the area of the applied force. If the area increases; the stress concentration

decreases.

Figure 9 Bending momentum and diflection equation

So, it is essential to consider length width and thickness of the material which is assigned for the

construction of B-pillar and reinforcement.

5.1.2 Location of restraints

It is appropriate to study about the clamping given to the B-pillar and the weld joints used between

the B-pillar, its reinforcement and with the support structure. The clamping and weld joints provide

stiffness to the structure, but in the other hand it becomes the reasoning for stress concentrations, a

proper well defined clamping of B-pillar and its reinforcement can help to reduce the overall stress

concentration along with minimum displacement .

Figure 10 clamping on B-pillar

5.1.3 B-pillar Architecture

Another one important factors in the performance of B-pillar and it reinforcement is the basic

structure. It should be simple and easy to manufacture; with a less complicated technique.

Generally, the B pillar is a top hat section which is formed by the die stamping of sheet metal. The

top hat structure provides rigidity of C-section at the top surface and at the two sides it provides the

stiffness of L-section. This kind of structure also provides housing for the door panels too. The

following figure illustrates the different methodology adopted for the design of B-pillar and kinds of

reinforcements.

Figure 11 types of reinforcement and structure

5.1.4 Second Moment of Area

The second moment of area, also known as moment of inertia of plane area, is a geometrical

property of an area which shows how its inertial points are distributed with regard to an arbitrary

axis. In the field of structural engineering, the second moment of area of the cross-section of

a beam is an important property used in the calculation of the beam's deflection and the calculation

of stress caused by a moment applied to the beam.

Figure 12 equations for calculation of second moment of inertia of I, T and C section

5.1.5 Existing B-pillar design

The existing b pillar designs are verified to understand the current design trends in B-pillar

modification. From the research it is concludes that almost all of the auto manufacturers uses the

same materials with slight different properties. The designs of B-pillar reinforcements, and different

clamping positions and outer support structure were also studied for the optimisation of B-pillar

reinforcement.

Figure 13 B-pillar side and sectional view

5.1.6 Factor of safety:

Every material manufactured is considered to have a safety factor, it is the capability of a material to

withstand the subjected load beyond the expected level. Factor of safety determine the range of

load subjected to the material. It is the ratio of ultimate stress to the yield stress.

𝐹𝑎𝑐𝑡𝑜𝑟 𝑜𝑓 𝑆𝑎𝑓𝑒𝑡𝑦 =𝑢𝑙𝑡𝑖𝑚𝑎𝑡𝑒 𝑆𝑡𝑟𝑒𝑠𝑠

𝑌𝑖𝑒𝑙𝑑 𝑠𝑡𝑟𝑒𝑠𝑠

6. DEVELOPMENT OF IDEA

As the initial step, the given B-pillar is analysed using the Generative Structural Analysis tool of the

CATIA. Here the given surface is provided with the appropriate material properties along with the

thickness. The surface is meshed using OCTREE Triangular Mesher having a value of 5mm with the

default proportional saga constrains. Two separate clamping are provided on the two sides of the

pillar. And a distributed load of 140kN is applied over it. The B-pillar is analysed and the von mises

stress variation and deformation is noted down.

Von Mises stress : Maximum- 10,000 MPa Minimum-80 MPa

Displacement : Maximum- 49mm

Figure 14 B-pillar analysis

6.1 Initial idea After the analysis of Von Mises stress of B-pillar, it was evident that stress is more concentrated on

the top portion of the B pillar. And it is theoretically provable that the stress concentration on the

top portion is mainly due to the lesser area of the B-pillar design. Along with this, manufacturability

and thickness were two factors which were to be considered for an optimal design. The line analysis

connects and its number was also a challenging task when the initial design is assigned.

As the initial design, the reinforcement is designed using the references from the given B-pillar. The

design is developed using the CATIA software provided by Desalt System. With the use of

commands, like, split, projections, extrude, fill, multi-section sweep etc the surface model for the

reinforcement is generated. The major design modification was done based on the reduction of

weight and adding stiffener on the place where stress is more concentrated on.

The section of the design is then generated structure is analysed and the result is verified. Though

the result was satisfactory for the main impact area of B pillar, the maximum von mises stress was at

the range of about 8000 MPa at the bottom hinges.

After carrying out a brief study, it is concluded that the higher stress is caused due to the bending

momentum acting at the hinges. Thus, the simplest way to reduce the stress concentration on

hinges is by providing the required weld and assigning clamping over those hinges.

The required weld connections are made and extra clamping are reassigned. Which provided a

better result.

Figure 15 initial design and analysis

7. FINAL DESIGN MODIFICATION

The final design is made after the research done on different frame structure. The area moment of

inertia, of the I-section, C-section and T-section was considered to finalise the final optimised design,

I-section provides better stiffness but the weight of the material become a counter effect while

considering it. The C-section is comparatively good but it is worth only if the two legs of C-section

are longer enough. Finally, the best desirable frame section is T section which is not as stiffer as I

section but has a lesser weight and closer stiffness to that of C-section. The moment of inertia of

area is calculated to determine the durability of T-section.

For the final design, the top hat section of the B-pillar is used to make a reinforcement having I

vertical stiffer over it. This stiffener along with the top part of hat section acts like a T-section, when

viewed from the side.

The reinforcement is assembled with the B-pillar and the analysis is carried out to generate

displacement and von mises stress. The displacement was optimised to a comparatively lesser value.

But, on considering the von mises stress result, the maximum stress is concentrated at the climbing

hinge at a rate of 4,900 MPa, and all other parts were optimised to an average range of below 800

MPa at a very low weight. The stress was a little bit higher on the two round edges at the sides of B-

pillar. So in order to reduce it another small plate of reinforcement is made between the b pillar and

primary reinforcement. The final optimisation is verified using the FEA analyser.

Final result

Von Mises Stress : Maximum- 4,924.51 MPa minimum- 1.195 MPa

Displacement : Maximum- 15.9mm minimum- 0

Figure 16 final design von Mises

Figure 17 mass of reinforced b pillar

7.1 Manufacturability of the reinforcement The B-pillar and its reinforcements are generally manufactured using die stamping and cutting. It is

one of the fastest production technique. The stamped B-pillar and reinforcement are welded

together to make reinforced B-pillar. This design if B-pillar reinforcement is designed completely

based on the giving emphasis to the time consuming manufacturing. The basic primary and

secondary reinforcement structure can be manufactured using die stamping technique and the

stiffener can be seam welded to the primary reinforcement. The weld joints between the pillar and

reinforcement are limited for exact requirement the ease of manufacturing.

8. ANALYSIS OF LOAD CASE DUE TO REINFORCEMENT

From the result, it is well under stood that the purpose of the reinforcement is to absorb the impact

load on the B-pillar and to distribute it to the side member of the vehicle structure to reduce the

deformation caused by the impact force. Thought the load case analysed in this course work is not

and impact load, it provides an approximate estimation of the structural strength of the B-pillar

under reinforced. Though the load case is considered under the elastic region, this case is not

considerable in real time impact analysis, as the deflection is too high for the B pillar without

reinforcement. But, for the reinforced design the deflection is coming very low which is well

desirable of an optimised design.

Without the reinforcement the von mises stress was too high, and was mainly concentrating on the

clamps. This is caused due to the bending moment acting at the clamps. Since the clamps are rigid

support, the displacement near by the clamps will be too low. Thus for the given load case, the

bending moment acting at that point will be too high. And, if the deflection is less, the stress which is

indirectly proportional to deflection, increases.

The maximum stress acting on the hinges can be either distributed to the reinforcement by giving

weld joints or by increasing the surface area of the reinforcement and clamping it.

9. 2D CAD DRAWING

9.1 Reinforced B-Pillar

Figure 18: Isometric view of reinforced B-pillar

9.2 Reinforcement

Figure 19: B-pillar Drafting

9.3 Primary Reinforcement

Figure 20: Primary reinforcement drafting

9.4 Secondary Reinforcement

Figure 21: secondary Reinforcement Drafting

9.5 Exploded View

Figure 22: Exploded view Drafting

10. CONCLUSION AND RECOMMENDATION

10.1 Conclusions

From the final design, the result was successfully generated. The basic requirement of displacement

below 40 mm is optimised to a lesser value of about 15 mm with taking into consideration the

weight and manufacturability of the pillar. The pillar is designed under the mass level of less than 6

kg. The use of two reinforcements improved the stress distribution in the main impact surface and it

is under the considerable factor of safety range. The size of the component was however fairly large

and this definitely contributed to the low stress values and displacement. Throughout the course of

this assignment, it was understood that just by welding a plate or adding mass to the reinforcement

plate will not provide the required results. The aim was to try and bring the final designs as close to

existing models as possible.

10.2 Recommendations

From the studies it was understood that, if the area of the clamping body can be increased

then the value of the von Mises can be reduced further more.

The use of I-section-section and H-section as the reinforcement with proper dimension is

recommended for further development.

The addition of adhesives or foam between plates and B-pillar will also help to improve the

crash performance with a lesser weight.

The beads can also be used in the appropriate portions of the design to reduce the stress

concentration.

10. 3 Limitations of FEA solver

Meshing become a time consuming factor when the design get complicated and mesh size is

higher.

Line analysis connections are difficult to perform, and weld joint error are hard to identify.

Error citation is difficult in CATIA.

Stress concentration at very small area is hardly not been cited it the von mises colour

graph.

11. REFERENCE

Anderson, T. L. (2006). Fracture Mechanics - Fundamental and Applications (3rd ed.). Florida: CRC

Press.

Bakker, A. (2006). Computational Fluid Dynamics. Retrieved 1 11, 2013, from

http://www.bakker.org/dartmouth06/engs150/07-mesh.pdf

CATIA. (2014). Screenshots. Coventry: Dassualt Systemes.

Hobbs, C. A., & Donough, P. J. (2006). Development of the Europen New Car Assessment Programme

(Euro NCAP). United Kingdom: Transport Research Laboratory.

Smitty. (2012). Fire EMS Blogs. Retrieved 01 10, 2014, from

http://boronextrication.com/2011/12/2012-mercedes-benz-m-class-body-structure/

12. APPENDIX

Material properties of high strength steel

Product Yield strength Tensile strength % elongation

HSS hot rolled 310-462 380-558 26-28

HSS cold rolled 303-370 372-445 26-27

SSLA 300-420 384-500 27-36

CP steel 800 1000 15-25

High alloy 1500 1700 8-15

Table1: High strength steel structural property

Equations for determining Second moment of inertia for the surface and weld joints. for various

structures

Calculation of Moment of inertia, Bending moment, Deflection and Factor of safety: