After you defined the substructure generation step or steps for your analysis, you must specify the retained degrees of freedom for a substructure. The retained degrees of freedom for a substructure node are the degrees of freedom that are external and are available for use in the analysis; all other degrees of freedom for the specified node are assumed to be internal to the substructure and do not factor into the analysis. When you can specify the node or region for which you want to define a Retained nodal dofs boundary condition, Abaqus/CAE displays the affected nodes in light blue, which enables you to pick them from a part instance or assembly easily.
