Ansys Employee
,nI see that you have a free rotation DOF (along y) right? This will likely case the plate to rotate, when a force is applied, which is likely the reason for pivotal error. When you have a bolt going through a washer, it exerts pressure on the surface of bolt and the resulting friction force between washer and mating surface prevents it for rotating, right? Since you have not considered the friction force here you have to provide an additional constraint to the washer. Either fix the Y rotation (which will be equivalent to a fixed support) or give zero displacements ( free only the normal to plate direction) to the sides .nRegards,nIshan.n