I am running a simulation and I need to see if the bolts will hold, but the model keeps telling me that there is a large displacement. A little while later, it tells me it cannot run the study because of abnormal bolt pretension. Is there something I am doing wrong? I have 16 bolts all pretorqued to 150 lb-in.
Large displacement can occur when the model is not properly fixed. You should check if there are Degrees Of Freedom (DOFs) left in your model. When using bolts it usually occurs if the tight fit option in the bolt properties is not selected.