A Plate Constraint causes all of its constrained joints to move together as a planar plate that is rigid against bending (out-of-plane) deformation. This constraint can be used as follows:
Connect structural-type objects (frames and shells) to solid-type elements (planes, Asolids, and solids); the rotation in the structural object can be converted to a pair of equal and opposite translations in the solid object by the Constraint.
Enforce the assumption that “plane sections remain plane” in detailed models of beam bending.
The constraint must apply to at least two joints to have any effect on the model. It is intended to be used on a set of joints that lie in a flat plane. However, even if the joints are not co-planar, this constraint will not have any adverse restraining effect on the model.
Use the following areas on the Plate Constraints form to make the appropriate entries:
Constraint Name. Use the default or enter a unique name for the constraint being defined.
Coordinate System. Choose the coordinate system in which the constraint axis is being defined. If the constraint axis is automatic (see the next bullet), the choice of coordinate system has no effect on the constraint.
Constraint Axis. The constraint equations will be written for a plate in a plane perpendicular to the selected axis. If the joints lie in a unique plane, it is usually best to choose Auto and let the program automatically determine the axis. This axis does not necessarily need to be parallel to a coordinate-system direction. If the joints are not coplanar, or to force a particular direction, choose the axis in the chosen coordinate system that is perpendicular to the plate. For example, if the Z axis is chosen, this constraint is equivalent to a body constraint in the same coordinate system with translation Z and rotations X and Y chosen.
If the Define menu > Joint Constraints command was used to access the Plate Constraints form, the defined constraint must be assigned to the joints.
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Access the Plate Constraints form as follows:
Click the Define menu > Joint Constraints command to display the Define Constraints form, or select a joint and click the Assign menu > Joint > Constraints command to display the Define/Assign Constraints form. Then do one of the following:
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