Hi everyone,

I'm reaching out for some guidance or suggestions on how you would approach the following problem.

The setup involves a spring, two bolts, and a flat component (the black part) that the spring is meant to push downward. The task is to preload the bolts, which in turn hold the spring in place and constrain the black part.

The assembly I received contains the spring in its undeformed, default shape and position. However, in this state, the spring intersects with multiple components. Normally, I would handle such issues using interference fit, which allows one part to morph into the shape of another. This method has worked reliably for me in the past but not this time. I suspect the issue may stem from the number of surface contacts involved in this setup.

What I want to achieve is simple in theory: the bottom surface of the spring should be in contact with the top surface of the black part. As shown in the attached images, I have selected these surfaces accordingly. However, I suspect that due to the general contact formulation, additional unintended surfaces are interfering. I have tried excluding those from the general contact definition, but I’m still running into issues like zero-volume elements and pivot warnings.

I have attached a few screenshots that illustrate the situation. If anyone has ideas or knows a clever workaround I might be overlooking I would greatly appreciate your input. 

Thanks in advance!