*TIE

Define surface-based tie and cyclic symmetry constraints or coupled acoustic-structural interactions.

This option is used to impose tie constraints, cyclic symmetry constraints, or coupled acoustic-structural interactions between pairs of surfaces.

This page discusses:

See Also
In Other Guides
Mesh Tie Constraints
Element-Based Surface Definition
Node-Based Surface Definition
Analysis of Models That Exhibit Cyclic Symmetry
Acoustic, Shock, and Coupled Acoustic-Structural Analysis

ProductsAbaqus/StandardAbaqus/Explicit

TypeModel data

LevelPartPart instanceAssembly

Required parameters

NAME

Set this parameter equal to a label that will be used to refer to the constraint.

Optional, mutually exclusive parameters

POSITION TOLERANCE

Set this parameter equal to a cutoff distance that is used to determine which nodes on the secondary surface are tied to the main surface. The calculation of the distance between the secondary and main surface for a particular secondary node depends on factors such as shell element thickness, the setting of the TYPE parameter, and the types of surfaces involved. Secondary nodes that do not satisfy the position tolerance are not tied to the main surface. The default value for this tolerance distance depends on the type of formulation and surfaces used in the constraints.

TIED NSET

Set this parameter equal to the node set label of the node set that includes the nodes on the secondary surface that will be tied to the main surface. Nodes not included in this node set will not be tied.

Optional parameters

ADJUST

Set ADJUST=YES (default) to move all tied nodes on the secondary surface onto the main surface in the initial configuration, without any strain.

Set ADJUST=NO if the secondary nodes will not be moved. This is the default if the secondary surface belongs to a substructure or if one or more of the surfaces is beam element-based.

CONSTRAINT RATIO

This parameter applies only when two surfaces with rotational degrees of freedom are tied with an offset but the NO ROTATION parameter is used.

Set this parameter equal to the fractional distance between the main reference surface and the secondary node at which the translational constraint should act. By default, Abaqus will attempt to choose this distance such that the translational constraint acts precisely at the interface.

CYCLIC SYMMETRY

This parameter can be used only in conjunction with the CYCLIC SYMMETRY MODEL option.

Include this parameter to invoke a constraint between the faces bounding a repetitive sector of a cyclic symmetric structure.

NO PORE

Include this parameter if pore pressure degrees of freedom should not be tied.

If this parameter is omitted, any pore pressure degrees of freedom are tied if applicable.

NO ROTATION

Include this parameter if rotation degrees of freedom should not be tied.

If this parameter is omitted, any existing rotation degrees of freedom are tied if applicable (in addition to the translation degrees of freedom).

NO TEMPERATURE

Include this parameter if temperature degrees of freedom should not be tied.

If this parameter is omitted, any existing temperature degrees of freedom are tied if applicable.

NO THICKNESS

Include this parameter to ignore shell thickness effects in calculations involving position tolerances and adjustments for initial gaps.

TYPE

Set TYPE=SURFACE TO SURFACE (default for most cases in Abaqus/Standard) to have the tie coefficients generated such that stress accuracy is optimized for the specified surface type pairings.

Set TYPE=NODE TO SURFACE (default for all cases in Abaqus/Explicit) to have the tie coefficients generated according to the interpolation functions at the point where the secondary node projects onto the main surface.

Data lines to define the surfaces forming the constraint pairs

First line

  1. The secondary surface name.

  2. The main surface name.

Repeat this data line as often as necessary to define all the surfaces forming the constraint pairs. Each data line defines a pair of surfaces that will be tied together.