Specifications

CT Corsair Final Report May 2, 2014
38
Figure 48: Failure of Scale Model
Once the physical tensile test was performed, the results
were acquired. From the tensile test, it was found that the
quarter-scale arm failed in shear at a 45 degree angle to the
hole, as can be seen in Figure 48. This showed that the
highest concentration of stress was in fact not at the tip of
the bearing holes, but rather at a 45 degree angle to the side
or the top of the holes. This deviation from the analysis
could have been due to the fact that our loading was slightly
different than what was in the FEA, yet it is also found that
for aluminum components stressed in tension this was typical.
The final results for the physical tensile test were that the quarter-scale arm failed in shear at a 45
degree angle at a max loading of about 600 lb. The stress-strain curve can also be seen in Figure
49, which also shows that yielding begins at approximately 17,000-18,000 psi. These values
accurately match the expected results from our FEA, which verified the scissor arm FEA.
Figure 49: Stress-Strain Curve of Scale Model Failure
8.5.5 Finite Element Analysis Results
From the results of our FEA, the upper scissor arm, manufactured from aluminum 6061-T6
material, fails at the bearing holes around an applied force of 5,000 lb. Since the maximum
weight the simulator ever imposes on the bearing holes is approximately 1,250lbs, the scissor
arms are strong enough to support forces that act upon it. These results were verified by
performing a physical tensile test on a quarter-scale arm and found that the results obtained
matched a similar FEA performed on a quarter-scale arm.