Imposed displacements

Imposed displacements can be assigned in the acting direction of any pipe support, link, or restraint. Imposed displacements do not have to have their own separate load pattern, they can be assigned to an existing load pattern such at T1, T2, etc. There are no limits to the number of imposed displacements which can be assigned, and imposed displacements can be applied as static or time history loading.

In this example we assign a 1" Z direction displacement to the selected anchor in the T2 thermal load pattern to account for thermal growth of attached equipment using Assign menu>Point loads>Ground displacement. Since the model was in feet units, typing 1" was automatically converted into feet units. 

Below we zoom into a skewed direction anchor with pipe support local axes graphically displayed. Anchors, guides, line stops, and distributed supports (soil) have local axes which by default align with the piping local axes. Local 1 is the red arrow, which is the longitudinal direction of the pipe, green arrow is local 2 and blue arrow is local 3. CSiPlant enables users to assign imposed displacement loads using local or global axes. In this example we defined an installation load pattern INSTALL and we assign imposed displacements using the Local coordinate system as shown below right in inch units.

Here we select the skewed anchor and generate an output result table for pipe support reactions in Local coordinate using Display menu>Show Tables.

Imposed Displacements at soil distributed supports

Imposed displacements are needed to account for soil subsidence and soil settlement.  Imposed displacements at distributed supports with examples