Applied Displacements

An applied displacement allows a fixed displacement to be applied to a node in the structure and calculates the deformation of the structure which results in the specified displacement at the specified degree of freedom. Thus applied displacements may be used to investigate the stiffness of a structure by constraining certain degrees of freedom to move by a fixed amount and noting the forces involved.

Applied displacements are different to the other load types and are also distinct from settlements.

Applied displacements apply to a particular load case and the node is free in all other load cases. Warning – applied displacements should not be used in conjunction with other loading in the same analysis case.

Applied displacements are handled by using Lagrange multipliers.

Applied displacements can be applied in local (i.e. node constraint axis), global or user defined axis directions. User axes can be Cartesian, cylindrical or spherical.

Definition

Name

The name is only used as a convenient way of identifying a load. Optional.

Node List

This specifies a list of nodes to be displaced using any one of the forms detailed in “Lists”. The list may be a single item.

In sculpt: The node list is set to the current selection set. The node list cannot be edited in the dialog.

Load case

This is the load case in which the displacement applies. The load case gives a way of grouping load effects together.

Axis

The axis in which the displacement is applied (global by default).

Direction

The direction of the loading, in the specified axis direction.

Value

The magnitude of the displacement or rotation.