The Frequency-Domain Perturbation (
) study step is used for studying small oscillations about a biased solution (small-signal analysis).
When this study step is added to the Model Builder as part of a two-step study, the first step is usually a Stationary study step that computes the stationary (or bias) solution. The second step is the
Frequency-Domain Perturbation step, which computes a perturbed solution of the linearized problem around the linearization point (or bias point) computed in the first step.
To add harmonic perturbation, see Harmonic Perturbation — Exclusive and Contributing Nodes. See also
linper for information about the
linper operator for indicating load terms that should be used by stationary solvers setting for harmonic linear perturbation. If your license include the Structural Mechanics Module, then also see
Harmonic Perturbation in the
Structural Mechanics Module User’s Guide.
From the Settings list, choose
Physics controlled (the default) to use linearization point settings controlled by the physics interfaces. Choose
User defined to specify the linearization point using the
Method list. Select:
Use the Study list to specify which solution to use from the available studies. Select: