Inverse Solving for Nonlinear Static Structural Analyses
The basic difference between a traditional (forward) analysis and the use of the Inverse Option, is the
state of the initial geometry. For a forward solution process, the initial geometry is deformed under
loading conditions and results are evaluated on the deformed geometry. While using the Inverse
Option for your solution, you begin with a known input geometry that is already deformed under a
set of loads that produced the deformation. Therefore, the solution output generated by the solver
is the geometry (also referred to as solution geometry or reference geometry) that would have existed
without the application of the loads. However, the result values are always calculated on the input
geometry during the inverse stage of the solution.
For both solution processes, the basic concepts, solution approaches, and steps are the same.
Inverse solving is only supported for Static Structural nonlinear analyses with the
Large Deflection property set to On, that is, when the deformations may be large enough
to affect the solutions results.
To perform inverse solving, simply set the Inverse Option property to Yes in the Advanced cat-
egory of the Analysis Settings. Setting the property to Yes also displays the End Step property.
The End Step property specifies the step number in the analysis when the inverse solving routine
ends. The default value of End Step is 1 and is read-only (unless Beta Options options are enabled).
The steps in the analysis until the End Step of Inverse Option are referred to as inverse steps. The
steps in the analysis that occur after the End Step of the Inverse Option are referred as forward steps.