Frequency Domain
The Frequency Domain () study and study step are used to compute the response of a linear or linearized model subjected to harmonic excitation for one or several frequencies.
For example, in solid mechanics, it is used to compute the frequency response of a mechanical structure with respect to particular load distributions and frequencies. In acoustics and electromagnetics, it is used to compute the transmission and reflection versus frequency. A Frequency Domain study step accounts for the effects of all eigenmodes that are properly resolved by the mesh and how they couple with the applied loads or excitations. The output of a Frequency Domain study step is typically displayed as a transfer function, for example, magnitude or phase of deformation, sound pressure, impedance, or scattering parameters versus frequency.
It is also possible to add an auxiliary sweep to this study step, which creates a multiparameter sweep (Parametric solver) over both the frequency and the given parameters, and optionally with continuation in the frequency or in one of the given parameters. It corresponds to a stationary parametric solver that is preset to linearize the equations (Stationary Solver with a Parametric attribute).
Alternatively, select the Use asymptotic waveform evaluation check box to use an AWE Solver instead of the Parametric solver.
The Include geometric nonlinearity check box, Results While Solving, Mesh Selection, Adaptation and Error Estimates, and Auxiliary Sweep are described in Common Study Step Settings. There is also detailed information in the Physics and Variables Selection and Values of Dependent Variables sections.
Study Settings
Select a Frequency/parameter list method. This option only appears if there are active least-squares objective functions defined in the model. The default is Manual, which means that the frequency list defined in the Frequencies field is used. The other possibility is From least-squares objective, which means that the frequency list defined by least-squares objectives is used.
Specify the frequencies to use for the frequency sweep. Select the unit to use from the Frequency unit list (default: Hz). Type the frequencies in the Frequencies field using space-separated numbers or the range function.
Use the Load parameter values field to select a file with parameter values. You can browse your file system for files by clicking the Browse button. After selecting a file, click the Read File button to load the parameter values into the Frequencies field.
For information about the Reuse solution from previous step list, see Reuse Solution from Previous Step List.
Study Extensions
Also see Auxiliary Sweep.
Asymptotic Waveform Evaluation
Select the Use asymptotic waveform evaluation check box to enable the asymptotic waveform evaluation (AWE) solver. The Frequency Domain study generates a solver configuration that is used to solve a stationary parametric problem or an asymptotic waveform evaluation problem. By selecting this check box, this study step corresponds to an AWE Solver.
Distribute Parametric Solver
If you are running a parametric sweep and want to distribute it by sending one parameter value to each compute node, select the Distribute parametric solver check box. This requires that your study includes a parametric sweep. To enable this option, click the Show button () and select Advanced Study Options.