This page contains the findings for conducting FEA on the steering arm.
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Vy = 1054.575 N
Mx = 54.8379 N⋅m
My = 147.6405 N⋅m
Mz = 173.5619535 N⋅m
| Date | Max Stress and Max Deformation | What I learned | Questions after doing the analysis |
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| 11/04/19 | Max stress = 658.19 MPa Max deformation = 1.2123 mm | - FEA SEEMS TO BE LINING UP WITH MY CALCS! In the right range!
- Sharp corners are likely to have the highest stresses. This was also observed by fixing the hole surface of the rod end hole; the pointed edge of the hole had the highest stress in that case.
- Filleting seems to be good
- Bend doesn’t affect it a lot
- The mesh doesn’t need to be crazy small
- It’s okay if it’s not like the previous steering arm, since our loading case is different
| - Why are our loading conditions so different from MSXII’s?
- What happens when you make it thinner and taller? This increases moment of inertia; is it better for torsion? Test this tomorrow
- How does it work without any fillets? Test this tomorrow
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| 11/05/19 | Max stress = 233.59 MPa Max deformation = 0.84289 mm | - Making the arm thinner was an okay idea
- Refining mesh made results more predictable
- Filleting isn't crucial
- Our culprit is not the rod end hole, but the steering bracket hole
- MESH CONVERGENCE WAS NOT TESTED and this needs to be done tomorrow!
| - Can we add weight reduction slots? Is it better on the top, bottom, left, or right sides?
- Should the wall thickness change around the steering bracket hole? Maybe the shape shouldn't be so rectangular there? Look into other shapes.
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| 11/07/19 | Max stress = 293.7 MPa Max deformation = 1.1682 mm | - Started looking into convergence. Dilemma: the Mesh Numbering object must be used to allow Ansys to recognize that the 32k nodes (max number of nodes for student version) hasn't been reached, BUT you can't use Mesh Numbering with the automatic convergence object. It's just not allowed
- We might wanna make the end that attaches to the steering bracket even beefier. But the steering bracket is to be changed soon so the contact points will likely be changed as well.
- Going forward, there definitely are stress concentrations at edges. Deal with this by filleting and removing/filleting the bend in the arm. The bend doesn't need to be so prominent. Brainstorm a more creative way to get flat surface at steering bracket end without the stress concentration in the bend
| - Should the end attached to the steering bracket end be beefier? Is that normal?
- What is the maximum acceptable deflection?
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| 11/08/19 | Max stress = 361.68 MPa Max deformation = 1.7686 mm
| - The end of the steering arm was changed to be a clevis end. It's failing at the edge of the hole in the clevis end.
- The clevis end should be thicker. To accommodate for this, extra material can be removed in the middle (i.e. the side profile should look tapered, not like a rectangle so much anymore)
| - How do different rod end thread sizes (i.e. hole sizes) impact the stress?? TEST THIS WITH SEVERAL GEOMETRIES! Try M10, M12, M14, M16 tomorrow
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| 11/24/19 | Max stress = 99.646 MPa Max deformation = 0.0064676 mm Min safety factor = 2.5089 |
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| - NEW LOADING CASE is way more realistic
- Loading calculations in google sheet seem accurate except for at stress concentrations
- Steering arm is likely overbuilt but that is okay for DFM, also for load cases we haven't considered
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| 12/05/2019 | Max stress = 179.83 MPa Max deformation = 0.29162 mm Min safety factor = 2.4467  Image Added
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| - geometry got changed so steering arm is now raised towards the front of the car
- most dimensions remained the same, some changed to allow stuff to fit better
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