Skip to end of metadata
Go to start of metadata
You are viewing an old version of this page. View the current version.
Compare with Current
View Page History
« Previous
Version 2
Next »
Date
Attendees
Goals
Discussion items
Item | Procedure | Media | Analysis |
---|
General | - Performed with Professor Rho in Golisano 1190
- Used MTS 45G Tensile Tester
- Performed test according to ASTM D5868
- Graphs generated in Excel
|
Load vs Displacement for All Samples
Alignment of CF Dog Bone in Fixture
Alignment of Lap Shear Sample in Fixture
Comparison of Surface Finishes of IREC 2022 (bottom) and 9/17 (top) winds | - All sampled follow a similar modulus of elasticity
- Sample 1 experienced significant slippage and therefore experienced significant displacement
- It was difficult to effectively use the shims
- Some shims were slightly too big
- Even at best the samples were not perfectly vertical
- The shims sometimes slipped in the fixture
- All tests were performed using a strain rate, however in an actual application each load would be instantaneous
- The surface finishes of each CF sample were significantly different
- The IREC 2022 wind had a more uniform and smoother surface finish on the inside face
- The 9/17 wind had divots and blemishes, resulting in stress concentrations in certain parts of the sample
- Stress could not be calculated due to complex part geometry
Conclusion: - Surface finish/wind quality matters
- The epoxy matrices failed first, followed by the CF fibers
- Preparation of an adhesion join is important
|
Lap Shear | - Used 3 in grip separation
- Created and used shims to align samples vertically
- Tested Aluminum-Aluminum, Aluminum-CF, and CF-CF bonds
- Used strain rate of 13mm (0.5in) per min
- Labelled parts 1 through 7
- Tightened bottom jaw first
|
- 1: Al-Al
- 2: Al-CF (9/17 wind)
- 3: Al-CF (9/17 wind)
- 4: CF-CF (9/17 wind)
- 5: CF-CF (9/17 wind)
- 6: CF-CF (2022 IREC wind)
- 7: CF-CF (2022 IREC wind)
Load vs Displacement for Lap Shear tests (omitting Sample 1) | - Sample 1 broke in fixture. Need to reapply epoxy
- Sample 2 broke at bond
- Sample 3 broke at CF part, failed due to poor surface finish
- Sample 4 broke at CF part, failed due to poor surface finish
- Sample 5 failed at CF part, however no significant deformation. CF part buckled
- Sample 6 failed at bond, epoxy bonded better with exterior surface finish
- Sample 7 failed at bond, epoxy bonded better to interior surface finish
- Samples 2 through 5 were the strongest of the lap shear samples
- Samples 3, 4, and 5 failed at the CF
- Sample 2 failed at the bond
- Samples 6 and 7 were the weakest
- They failed the same way
- the bonds were not as strong?
|
Dog Bone | - >1in in each jaw
- Used strain rate of 13mm (0.5in) per min
- Labelled parts 8 through 13
- CF samples
- Tightened top jaw first
|
- 8-9: 2022 IREC wind
- 10-13: 9/17 wind
Load vs Displacement for Dog Bone tests
| - All parts failed near jaws
- Jaws are flat, part is slightly curved. This caused stress concentrations
- Epoxy matrix failed first, then the CF fibers
- Buckling =/= total failure?
- After failure (the maximum load) each sample deformed prior to complete failure
- Samples 8 and 9 were the strongest
- This could be attributed to a better surface finish
- Better surface finish = stronger part?
|