Contact analyses require a careful, logical approach. Divide the analysis into several steps if necessary, and apply the loading slowly making sure that the contact conditions are well established.

In general, it is best to use a separate step for each part of the analysis even if it is just to change boundary conditions to loads. You will almost certainly end up with more steps than anticipated, but the model should converge much more easily. Contact analyses are much more difficult to complete if you try to apply all the loads in one step.

Achieve stable contact conditions between all components before applying the working loads to the structure. If necessary, apply temporary boundary conditions, which may be removed at a later stage. The final results should be unaffected, provided that the constraints produce no permanent deformation.

Do not apply boundary conditions to nodes on contact surfaces that constrain the node in the direction of contact. If there is friction, do not constrain these nodes in any degree of freedom: zero pivot messages may result.

Always try to use first-order elements for contact simulations.