Hi, I'm a new user to the forum, any help is much appreciated.
I'm trying to determine peak stress in a lower wishbone insert. The part has a compound load case applied, one leg of the wishbone in tension, one in compression, and a load on the mount bracket in double shear through the pushrod, see below.
In practice, the only constraint is that the spherical joint cannot translate, but rotation is permitted in all axes. Initially, I applied an advanced fixture on the spherical face which mimics the internal surface of the bearing housing, and applied the condition that radial displacement must equal zero. With this applied, the insert appears to displace correctly given the applied forces, yet I get huge artificial stress concentrations around the inside circumference of the spherical surface, see below.
The above result is achieved if I use an adaptive loop mesh. With a generic, fine mesh, the following is achieved.
I'm sure this isn't an uncommon thing to try and simulate, so hopefully there is a way to do this. In the meantime I am attempting to simulate the assembly, with the bearing included, using component contact fixtures and attempting the simulation by fix the bearings 'ball' instead.
Again, any advice welcome, thanks in advance.
James
This is the kind of thing that FEA is bad at--bolted joints, welds, rivets, bearings. Accurately simulating the force transfer between two components is really touchy, because a lot of the important effects depend on things that are difficult to know. You can do this type of analysis, but I wouldn't normally trust the results unless you take a pretty advanced approach.
I normally approach something like this by using FEA to design the bracket. Then I design the bearing attachment to the bracket using handbooks, hand calcs and manufacturers recommendations. Usually, straightforward F/A type bearing stress calculations are sufficient.