Team Members:Doug Bradley

Dan Ehlke

Strain Test Stand Finite Element Analysis (FEA) vs Physical

Testing School of Technology Lab Cheaply Load of up to 150 lbs Various length/geometry test specimens

Aluminum Frame

Force Application: weights

Plexiglass cover

Clamping system: standard clamp

Electronics: amplifier unit.

Data Output: Digital display of

voltage

Signal Conditioning: Tare function

to exclude the influence of

preloads.

Test Specimens: tensile test rods,

in aluminium, copper and brass

Force measurement: manually add

weight values

Determined the most important aspects of the design Accuracy/Precision User-friendliness Safety

Functional decomposition identified key parts

Closest to current SofT design

Leverage based sample holding system

Hanging weights apply force

Dial gauge measures displacement

Internal electronics for strain gauges

More stable frame design

Uses clamping system to hold sample

Hydraulic cylinder applies force

Dial gauge measures displacement

Internal electronics for strain gauges

Lighter frame design than concept 2

Uses chuck assembly to hold sample

Electronic linear actuator applies force

Dial gauge and internal electronics hookups not shown

Based on the important qualities determined by the QFD

Identified concepts 2 and 3 as best

Uses the stable U-frame (Concept 2)

Chuck assembly used for sample holding (Concept 3)

Pneumatic cylinder for force application (Concept 2)

Dial gauge and internal electronics as standard

Frame is load-bearing A500 Steel Tube 6 in X 4 in, .25 in

thick Top bar for stability

Under smaller loads Steel barstock 1 in diameter Free

Assumptions: ≤ 0.5 in deflection of sample

Calculated bore size ≥ 1.8 in

Next highest pneumatic size: 2.0 in

60 psi pressure source is unreliable, as is pressure gauge

Alternatives

KNOWN SOLVE FOR DIAMETER

F = ForceP = pressureA = Surface area of pneumatic cylinder boreD = Minimum Cylinder Bore DiameterF= 150 lb (10 lb increments)P= 60 lbs/in2

A = ?D = ?

F=pA150 lb = (60 lbs/in2) * AA = 2.5 in2 A = r2

Determine r2.5 in2 = r2

r = 0.89206D = r*2D = 1.784124

Screw Jack Control Constant

Load Cell Precise Measurement Automatic logging

4 jaw chuck

Steel frame

Force Application: Screw jack

Adjustable jack Placement

Clamping System: Four jaw chuck assembly

Adjustable chuck height

Internal Electronics: NI-DAQ 9237

Signal Conditioning: NI-DAQ 9237 &

Labview Software

Data Output: Graph of Strain / Force in

LabView

Test Specimens: 3 crowbars

Dimensions: 42” x 30” x 6

Force measurement: Honeywell Model 53

Load Cell