Hi,
I am using hypermesh v13 and optistruct v13 for bolt pretension analysis (Non linear Quasistatic analysis) for 4 cylinder inline engine. Components consist Cylinder head , head bolts , gasket and Cylinder block. Head bolts are inserted and they pass through cylinder head--gasket--cylinder block. Internal threads are present in block and external threads on bolt. will you please tell which type of contact should be used for contact between cylinder head bolt and cylinder block for optistruct solver ? There must be relative motion between them...right ? please give explaination too so that I can understand.