Convergence issues using pretension elements

[JHLynn]

Hello,

I have been working on a model for a few days that utilizes pretension elements to simulate bolt tension. The bolts are modeled as beam elements connected to the top and bottom of bolt holes by MPCs. The flanges the bolts hold together have contact surfaces between them that are set to not allow penetration and have a high friction coefficient to allow sliding.

This model worked on an earlier iteration perfectly, but now that I have sized the bolts much larger to 1.5 inch bolts, around 67 ksi of pretension per bolt, the model fails to converge in an initial loadstep applying the boundary conditions and pretension.

I was wondering if anyone knows what would cause this convergence issue and if there are any suggestions to correct it?

Thank you

 

[Drej]

I've had convergence failures with these previously, mostly owing to rigid body motion of the part/s. Try applying grounded weak springs to the model to prevent this.


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