Contact Points
The points considered in user subroutine VFRICTION are called contact points. Each contact point is primarily associated with a secondary node or a point along a secondary edge; the contact point also references the corresponding main surface that it contacts. A contact point exists for each pairing of secondary node and main surface. Therefore, more than one contact point may reference the same secondary node but different main surfaces, such as with contact at a corner.
The number of contact points currently being passed into user subroutine VFRICTION is nBlock. The array jConSecUid(nNodSec,nBlock) gives the secondary surface node numbers associated with the contact points. The variable nNodSec indicates whether a single secondary node (for node-to-face contact) or two secondary nodes of an edge (for edge-to-edge contact) are associated with each contact point. Similarly, the array jConMainUid(nNodMain,nBlockAnal) gives the main surface node numbers associated with each contact point; the nodes can belong to a facet, an edge, or an analytical surface. The variable nNodMain indicates the number of main nodes associated with each contact point.
An Abaqus/Explicit model can be defined in terms of an assembly of part instances (see Assembly Definition). In such models a node number is an internally generated node number. If the original node number and part instance name are required, call the utility routine VGETPARTINFO (see Obtaining Part Information).