General Options
| Construct | Coupling to points: Couples edges or faces to the motion of a reference point. Coupled faces/edges: Couples edges or faces of a 3D solid part to an edge on another 3D solid part. Shell edge to solid face: Couples an edge (or edges) of a 2D shell part to a face (or faces) of a 3D solid part. This option lets you transition from shell element modeling to solid (continuum) element modeling in a three-dimensional simulation. It is most useful when a particular region needs full 3D simulation modeling but other regions of the structure can be modeled as 2D shells. |
| Coupling type | If you are coupling a face to another face, edge, or vertex, two couplings are created with a zero-length connector in between. You can choose different coupling types for the coupling at each support. Kinematic: Directly couples the motion of the edges or faces to the rigid body motion of the reference point. Continuum distributing: Couples the motion of the edges/faces to the motion of the reference point, but the coupling is averaged with weight factors controlling the transmission of forces from the reference point to the other supports. A continuum distributing coupling couples the translation and rotation of the reference point to the average translation of the coupling nodes. No moments are distributed at the coupling nodes. Structural distributing: Couples the motion of the edges/faces to the motion of the reference point, but the coupling is averaged with weight factors controlling the transmission of forces from the reference point to the other supports. A structural distributing coupling couples the translation and rotation of the reference point to the translation and rotation of the coupling nodes. |
| Constrained degrees of freedom | If the supports are a vertex and either a face or edge, you can choose specific degrees of freedom to fix at the face or edge. For a distributing coupling, the translational degrees of freedom (Tx, Ty, Tz) are constrained automatically and cannot be deselected. |
| Axis system definition | Global: Aligns the local feature
triad with the global coordinate system. Local: Aligns the local feature triad with
a selected axis system in the model. |
| Axis system type |
Cartesian: Selected axis system uses Cartesian
coordinates.
Cylindrical: Selected axis system uses cylindrical
coordinates. The Z-direction is used as the reference axis.
|
| Use spring | Use a spring instead of a rigid coupling. |
| Spring type | Linear axial: Defined by a single spring constant. Linear general: Defined by constants in each primary direction and rotation. Nonlinear axial: Defined by force-displacement data in a single direction. Nonlinear general: Defined by force-displacement data in each linear and rotational direction. |
| Axis system definition | Choose Global or
Local
axis system for the spring orientation. |
Coupling to Point Construct Options
The Influence radius specifies the radius within which the nodes are
included in the coupling.
For Kinematic couplings, when one or more degrees of freedom are
cleared, the following choices are available for the Release DOF(s)
at: option:
| Option |
Description |
| Reference Point |
For the cleared DOFs, prevents rotations or translations applied at the
reference point from being transmitted to the coupling nodes. |
| Coupling nodes |
For the cleared DOFs, prevents rotations or translations applied at the
coupling nodes from being constrained by the motion of the reference
point. |
For Continuum distributing and Structural
distributing couplings, the following weighting options are available:
| Option |
Description |
| Uniform |
Maintains an equal weight factor on all nodes within the influence
radius. |
| Linear |
Decreases the weight factor linearly with the distance from the fastening
point. |
| Quadratic |
Decreases the weight factor by a quadratic polynomial function of the
distance from the fastening point. |
| Cubic |
Decreases the weight factor by a cubic polynomial monotonic function of the
distance from the fastening point. |
Shell Edge to Solid Face Construct Options
| Position tolerance | Set this tolerance to the distance within which nodes on the edge-based surface must lie from the solid surface to be included in the coupling. The default tolerance is 5% of the length of a typical facet on the shell edge. |
| Influence distance | Set this parameter to the perpendicular distance from the edge-based surface within which all nodes or element facets on the solid surface must lie to be included in the coupling. The default value is half the thickness of the shell used to define the edge-based surface. |
Note:
To fully define shell edge to solid face couplings for export, you must include the
involved 2D meshes in an element assignment. This completes the coupling by defining the
coupled surfaces.
Linear Axial Spring Options
Elasticity
| Stiffness 1
|
Spring constant (force per relative
displacement).
|
Reference Length
Reference lengths define the constitutive response for connector elements
generated by this feature. You can define the translational position at which
constitutive forces are zero by specifying the reference length. The default
value for the reference length is calculated automatically from the initial
geometry.
| Length associated with
Tx
|
Reference length associated with the
connector's first component of relative motion.
|
Linear General Spring Options
Elasticity
| Stiffness 1
|
Spring constant, X-direction (force per
relative displacement).
|
| Stiffness 2
|
Spring constant, Y-direction.
|
| Stiffness 3
|
Spring constant, Z-direction.
|
| Stiffness 4
|
Spring constant, X-rotation.
|
| Stiffness 5
|
Spring constant, Y-rotation.
|
| Stiffness 6
|
Spring constant, Z-rotation.
|
Reference Length
Reference lengths and angles define the constitutive response for
connector elements generated by this feature. You can define the translational
or angular positions at which constitutive forces and moments are zero by
specifying up to six reference values (one per component of relative motion):
three lengths and three angles. The default values for reference lengths and
angles are calculated automatically from the initial geometry.
| Length associated with
Tx
|
Reference length associated with the
connector's first component of relative motion.
|
| Length associated with
Ty
|
Reference length associated with the
connector's second component of relative motion.
|
| Length associated with
Tz
|
Reference length associated with the
connector's third component of relative motion.
|
| Angle associated with Rx
|
Reference angle associated with the connector's
fourth component of relative motion.
|
| Angle associated with Ry
|
Reference angle associated with the connector's
fifth component of relative motion.
|
| Angle associated with Rz
|
Reference angle associated with the connector's
sixth component of relative motion.
|
Nonlinear Axial Spring Options
Elasticity
| Data table
|
Force-displacement data along the spring axis.
You can enter tabular data manually or import the data from a file.
|
Reference Length
Reference lengths define the constitutive response for connector elements
generated by this feature. You can define the translational position at which
constitutive forces are zero by specifying the reference length. The default
value for the reference length is calculated automatically from the initial
geometry.
| Length associated with
Tx
|
Reference length associated with the
connector's first component of relative motion.
|
Nonlinear General Spring Options
Elasticity
The elasticity force-displacement data for a nonlinear
general spring are defined using a set of six data tables. Each table
corresponds to a directional or rotational component. Table 1 is for X-axis
data, and table 6 is for rotational data about the Z-axis.
| Data tables
Fx,
Fy,
Fz,
Mx,
My, and
Mz
|
Force-displacement data. You can enter tabular
data manually or import the data from a file.
|
Reference Length
Reference lengths and angles define the constitutive response for
connector elements generated by this feature. You can define the translational
or angular positions at which constitutive forces and moments are zero by
specifying up to six reference values (one per component of relative motion):
three lengths and three angles. The default values for reference lengths and
angles are calculated automatically from the initial geometry.
| Length associated with
Tx
|
Reference length associated with the
connector's first component of relative motion.
|
| Length associated with
Ty
|
Reference length associated with the
connector's second component of relative motion.
|
| Length associated with
Tz
|
Reference length associated with the
connector's third component of relative motion.
|
| Angle associated with Rx
|
Reference angle associated with the connector's
fourth component of relative motion.
|
| Angle associated with Ry
|
Reference angle associated with the connector's
fifth component of relative motion.
|
| Angle associated with Rz
|
Reference angle associated with the connector's
sixth component of relative motion.
|