Adding contact blocks to a model imported from Inventer into Simscape

I have imported an Inventer CAD model into simscape multibody and added contact blocks to the model, but the contact simulation does not work.

I don't think there is a problem with the contact blocks because I added them in Simscape after importing.

So I think the problem is with the solid blocks. Here are the imported solid blocks and the common solid blocks used in Simscape.

　　　　　　　　　　

↑common solid blocks　　　　　　　　　　↑imported solid blocks

What are the differences between the two solid blocks, and what are some tips and tricks for adding contact blocks to an imported model for simulation?

Answer 1

[Juan Sagarduy]

Hi there

You need a spatial force contact block taking in both geometries to resolve the contact. Modeling Contact Force Between Two Solids - MATLAB & Simulink (mathworks.com)

If the contact is not captured, it could be caused by a solver resolution issue (time step does not get small enough to capture the contact) or by that the convex hull approximation of the bodies leads to a non-realistic contact event.

If the problem persists, I'll recomend contacting our Technical Support to sort the root cause of the problem.

Good luck/Juan

[A]

Thank you for your answer.

Using your answer as a guide, I created a simple model in Inventor and imported it into MATLAB for simulation.

CAD models in Inventor and simulation results in MATLAB and their details are attached as ZIP files.

Can you tell us why the contact is not working properly?

[Juan Sagarduy]

Hi there

It looks to me as if you need to set a value for the max step size in the solver that is low enough. Try with 10e-6 and then see if the contact is captured. Then you can increase that value until the contact is no longer captured. This happens every now and then with contact simulations, the auto value for max step is tsim/50. so it is easy for Simulink to miss when the contact occurs.

let me know if this works.

BR Juan

[A]

After changing the maximum step size of the solver, the simulation was successful. Thank you very much.

The simulation results and solver are attached as a zip file.