Translation of support

A node of the structure may be subject to a prescribed displacement. In such a case, the user defines the direction and magnitude of the known displacement.

Parameters have the following meaning

Name

The name Is used for identification of the entity - translation of a support.

Direction

The direction specifies the direction in which the support "settles".

Reference

Absolute: The value (below) is input in absolute value related to the origin of the global coordinate system.

Relative:  The value (below) is input in relative value related to the position of the support.

See also the example later in this chapter.

Value - U

Specifies the value by which the support is translated.

System

(informative) The direction is always defined by the local coordinate system of the support.

 

The translation of support can be defined ONLY in fixed supports, it cannot be defined in flexible and non-linear supports.

Example

This example demonstrates the difference of absolute and relative reference.

Let us assume a simple three-span frame with supports as shown in the picture.

We have two identical frames: the left one for the absolute translation of the support, the right one for the relative translation. The global Z-coordinate of the lower supports is equal to zero, i.e. the supports are located in the global XY-plane.

The translation of a support is assigned to the support located in the middle of the middle-span beam.

The translation in the left frame is input with the following values:

The right variant with the following parameters:

The difference between the absolute andrelativereference can be clearly seen in the last picture (the height of the frame is 4 metres).