Sets created by selecting geometry from the assembly are called assembly sets, and you use the Set toolset to create and manage assembly sets. For example, you can select an assembly set to indicate where loads, boundary conditions, and interactions are applied. You can also use assembly sets to define regions of the model from which ABAQUS/CAE will generate output during the analysis; for example, selected vertices or faces. Assembly sets can include regions from multiple part instances.

In contrast, part sets are created by selecting geometry from a part in the Part module or the Property module. When you instance a part in the Assembly module, you can refer to any part sets that you previously created; however, ABAQUS provides only read-only access to these part sets in assembly-related modules. In addition, you cannot access a part set from the Set Manager in assembly-related modules; however, you can select an eligible part set during a procedure by clicking the Set button and selecting the set from the Region Selection dialog box that appears. For more information, see “Understanding sets and surfaces,” Section 48.2.

You create surfaces by selecting faces or edges from the assembly, and you use the Surface toolset to create and manage surfaces. Typically you select a surface when a procedure is expecting a face; for example, when you are applying distributed loads, such as pressure loads, and defining contact interactions. For more information, see “What is a surface?,” Section 48.2.3.