Node-based surface definition

A node-based “surface”:

• can be used only as a “slave surface” in contact calculations;

• can be used as a “slave” or “master surface” in a surface-based tie constraint;

• is convenient in three-dimensional cases where Abaqus cannot construct a unique physical surface on the elements, such as a pipe modeled with pipe elements contacting the ocean floor or cables modeled with trusses contacting the ground after they break;

• should be used with caution or not at all if accurate contact stresses are needed or if heat will be exchanged between the two surfaces;

• can be assigned a nonzero thickness for use with the general contact algorithm in Abaqus/Explicit;

• should not be used to model a shell or membrane surface if the thickness and midsurface offset need to be considered in the problem;

• must either contain nodes that are all part of the same rigid body or not contain any nodes that are part of a rigid body if the node-based surface is to be used in a penalty contact pair in Abaqus/Explicit;

• in Abaqus/Standard does not provide heat conduction between surfaces in fully coupled temperature-displacement analysis or pore fluid flow between surfaces in coupled pore pressure–displacement analysis;

• in Abaqus/Standard does not provide heat conduction and electrical conduction between surfaces in a fully coupled thermal-electrical-structural analysis; and

• does not include circumferential friction when used with axisymmetric elements with twist (CGAX, MGAX elements).

Alternatives to node-based surfaces are element-based surfaces (see Element-based surface definition) and, in the case of rigid surfaces, analytical rigid surfaces (see Analytical rigid surface definition). See Operating on surfaces for information on defining surfaces using Boolean combinations of existing surfaces.

The following topics are discussed:

• Creating a node-based surface