INTER203 Element Description

INTER203 is a 2D 6-node quadratic interface element used for 2D structural assembly modeling. When used with 2D quadratic structural elements (such as PLANE183), INTER203 simulates the interface surfaces and the subsequent delamination process, where the separation is represented by an increasing displacement between nodes, within the interface element itself, that are initially coincident. The element can be used either as a plane element (plane stress or plane strain) or as an axisymmetric element. It is defined by six nodes having two degrees of freedom at each node: translations in the nodal x and y directions.

See Cohesive Zone Material Model and INTER203 in the Mechanical APDL Theory Reference for more details about this element.

Also see Crack-Initiation and -Growth Simulation, Interface Delamination, and Fatigue Crack-Growth in the Fracture Analysis Guide for more information about the interface failure/delamination capability in Mechanical APDL.

Figure 203.1: INTER203 Geometry

INTER203 Input Data

The element geometry, node locations, connectivity, and the nodal coordinate system are shown in Figure 203.1: INTER203 Geometry. The element geometry is defined by 6 nodes, which form bottom and top lines of the element. The bottom line is defined by nodes I, J, M; and the top line is defined by nodes K, L, O. This element has 2 integration points. Dropping mid side nodes M or O is not permitted.

INTER203 is used to simulate a separation along an interface defined by this element. At the outset of your simulation, nodes I,L, nodes M,O and nodes J,K are coincident, with each other, and with the corresponding nodes in the adjacent structural elements. The subsequent separation of the adjacent elements (usually defined contiguously as components) is represented by an increasing displacement between the initially coincident nodes within this element.

Temperatures may be input as element body loads at the nodes. The node I temperature T(I), defaults to TUNIF. If all other temperatures are unspecified, they default to T(I). For any other input pattern, unspecified temperatures default to TUNIF.

Input the nodal forces, if any, per unit of depth for a plane analysis (except for KEYOPT(3) = 3) and on a full 360° basis for an axisymmetric analysis.

The next table summarizes the element input. See Element Input in the Element Reference for a general description of element input.

INTER203 Output Data

The solution output associated with the element is in two forms:

The output directions for element items are parallel to the local element coordinate system based on the element midplane as illustrated in Figure 203.2: INTER203 Stress Output. See Cohesive Zone Material Model and INTER203 in the Mechanical APDL Theory Reference for details.

A general description of solution output is given in Solution Output. See the Basic Analysis Guide for ways to review results.

Figure 203.2: INTER203 Stress Output

The Element Output Definitions table uses the following notation:

A colon (:) in the Name column indicates that the item can be accessed by the Component Name method (ETABLE, ESOL). The O column indicates the availability of the items in the file jobname.out. The R column indicates the availability of the items in the results file.

In either the O or R columns, “Y” indicates that the item is always available, a letter or number refers to a table footnote that describes when the item is conditionally available, and “-” indicates that the item is not available.

INTER203 Assumptions and Restrictions

INTER203 Product Restrictions

There are no product-specific restrictions for this element.