Description: Various robustness, performance, and functionality enhancements have been made for the supplementary edge-to-surface formulation of general contact in Abaqus/Standard. Now the edge-to-surface formulation considers perimeter edges and most significant geometric feature edges of three-dimensional bodies modeled with solid and shell elements by default. Previously, no features edges were considered by default and applicability of the edge-to-surface formulation was limited to edges of solid elements. General contact uses the edge-to-surface formulation in addition to the surface-to-surface formulation. The edge-to-surface formulation more accurately resolves certain contact scenarios involving feature edges than the node-to-surface formulation. Figure 10–3 and Figure 10–4 show an example involving contact with perimeter edges of a shell frame.

New output variables CSTRESSETOS and CDISPETOS are provided, which are useful to determine effects of the edge-to-surface formulation on preexisting, general-purpose output variables CSTRESS and CDISP. For example, CSTRESS reflects the sum of a contribution from the edge-to-surface formulation (corresponding to CSTRESSETOS) and a contribution from the surface-to-surface formulation. For cases in which CSTRESS is reported in units of force per area, the edge-to-surface formulation also reports contact stresses in these units, which results from dividing the contact force per edge length by a representative surface facet length.

Additional internal surfaces are generated to show which edges satisfy feature edge criteria for individual components. These internal surfaces have the naming convention General_Contact_Edges_k, where k corresponds to an automatically assigned component number. The same component numbers are assigned to internal surfaces showing surface faces: General_Contact_Faces_k (these surfaces used the naming convention General_Contact_Component_k in prior versions). Diagnostic messages for general contact refer to these internal surface names. For example, diagnostic messages related to contact status changes for the edge-to-surface formulation may refer to contact between nodes of General_Contact_Edges_2 and General_Contact_Faces_1. Internal surfaces can be viewed using display groups in the Visualization module of Abaqus/CAE. Figure 10–5 shows an example with one of each type of internal “component” surface displayed.

As in prior versions, internal surfaces showing all faces (General_Contact_Faces) and all edges (General_Contact_Edges) of the general contact domain are also provided.

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