3.2.5.1. Linear Algorithm

This command is used to construct a Linear algorithm object which takes one iteration to solve the system of equations.

algorithm Linear <-initial> <-factorOnce>

Argument	Type	Description
-initial	string	optional flag to indicate to use initial stiffness
-factorOnce	string	optional flag to indicate to only set up and factor matrix once

Note

As the tangent matrix typically will not change during the analysis in case of an elastic system it is highly advantageous to use the -factorOnce option. Do not use this option if you have a nonlinear system and you want the tangent used to be actual tangent at time of the analysis step.

The Linear algorithm REQUIRES NO test Command and will complain if one is provided. This means that convergence is not checked.

Certain transient explicit integration schemes require a Linear algorithm.

Example:

The following examples demonstrate the command to create a Linear solution algorithm.

1. Tcl Code

algorithm Linear

2. Python Code

algorithm('Linear')

Code Developed by: fmk