第四章 abaqus系列之接触.doc

接触笔记 1、Defining contact pairs in ABAQUS/Standard After the selection of contact pair surfaces, three key factors must be determined when creating a contact formulation: ⑴ the contact discretization; ⑵ the tracking approach; and ⑶ the assignment of “master” and “slave” roles to the respective surfaces. the contact discretization ABAQUS/Standard offers two contact discretization options: a traditional “node-to-surface” discretization and a true “surface-to-surface” discretization. 1.1.1 Node-to-surface contact discretization Traditional node-to-surface discretization has the following characteristics: ⑴ The slave nodes are constrained not to penetrate into the master surface; however, the nodes of the master surface can, in principle, penetrate into the slave surface ⑵ The contact direction is based on the normal of the master surface. ⑶ The only information needed for the slave surface is the location and surface area associated with each node; The direction of the slave surface normal and slave surface curvature are not relevant.Thus, the slave surface can be defined as a group of nodes—a node-based surface. ⑷ Node-to-surface discretization is available even if a node-based surface is not used in the contact pair definition Fig.1 Node-to-surface contact discretization 1.1.2 Surface-to-surface contact discretization To optimize stress accuracy, surface-to-surface discretization considers the shape of both the slave and master surfaces in the region of contact constraints. Surface-to-surface discretization has the following key characteristics: ⑴ Contact conditions are enforced in an average sense over the slave surface, rather than at discrete points (such as at slave nodes, as in the case of node-to-surface discretization). Therefore, some penetration may be observed at individual nodes; however, large, undetected penetrations of master nodes into the slave surface do not occur with this discretization. ⑵ Surface-to-surface discretization is not applicable if a