Using the Results while solving functionality in the study step is a good practice. You can either use a stress plot, or a plot of the contact pressure. In most cases, the scale of a deformed plot should be set to 1 when monitoring contact problems. Note that if you select Results while solving in the Segregated feature, the plot is updated after each iteration, thus allowing you to monitor the convergence in detail.

For each contact pair, two global variables that can be used in probe plots are available. These are the maximum contact pressure (solid.Tnmax_pair) and the minimum gap distance (solid.gapmin_pair).

Looking at the convergence plot will give valuable information about the convergence properties. There will, as a default, be one graph per Contact node in the Model Tree, which will help you pinpoint the source of a convergence problem. You can increase the granularity further, by selecting the Group contact variables in solver per pair check box in the Advanced section of the settings for the Contact node.

You can also select to include information about the contact state in the solver log. To do that, select the Add contact status to solver log check box in the Advanced section of the settings for the Contact node. For each contact pair, messages like