FEA approach for plastic snap
Hi everyone,
I am working on a plastic design task where I need to design a cover/lid that locks onto a mating plastic component.
The locking feature is inspired by a concept used in some existing products, but I have been told that it may not really be a classic elastic snap-fit. It may be closer to an interference/deformation locking feature, since the intention is that the cover should stay assembled permanently.
One difference in my current design is that the mating line/interface is not flat. The cover has to lock around a more 3D/organic surface, which makes the geometry harder to evaluate.
I have made a 3D printed PLA prototype of the concept, and mechanically it seems to work quite well. The cover can be pushed into place, it locks firmly, and I need a tool to remove it again. However, the final part will be injection molded in PP, which is softer and more flexible than PLA.
So I thought this could maybe be a good opportunity for me to use FEA on a real design case and use it as a learning opportunity to understand how this type of problem could be approached via FEA.
I only have basic university experience with ANSYS Mechanical, mainly static structural simulations, so I am trying to understand what a realistic first simulation approach would be.
My questions are:
- Does it make sense to simulate the assembly of this type of plastic locking feature as a learning and design exercise. If yes, what useful information could I realistically get from the simulation, snap deflection, insertion/removal force, contact pressure, or critical strain areas?
- What would be the correct approach for this? My initial thought is that it should be treated as a nonlinear contact analysis with large deflection. However, since the cover has to move into position during assembly, I am unsure whether this can still be done as a static structural analysis using prescribed displacement, or if some kind of dynamic analysis would be more appropriate.
Any advice would be appreciated.