Gary Stofan
Ansys Employee
Anytime you apply a force load to close (or clamp) a non-linear contact, it can be difficult to converge as the contact will often penetrate through each other.nThis is because the contact offers little or no initial stiffness while the load is starting to be applied.nA few tips:nApply the bolt load in multiple steps. 1st step, use a very small load. This will allow the contact to mate or resolve. 2nd step increase to full load.nAnd/Or apply a 0,0,0 displacement in the first step to hold the structure steady while the load is being applied. Deactivate the displacement to let go in the 2nd or subsequent steps.nConsider instead applying the bolt pretension as a (length) adjustment. Use the pretension reaction to determine if you are close to 7500 load. Displacements are often much easier to converge with nonlinear contacts that are pressures or forces.nA general internet search for the terms Ansys nonlinear contact convergence produces several resources that may be helpful.