To perform frequency analysis:
Create a frequency study. Right-click the top icon in the COSMOS AnalysisManager tree and select Study to access the Study dialog. Define the Properties of the study to set the number of frequencies. The program calculates the lowest five modes by default in addition to any rigid body modes.
Define material for each solid, shell, and beam. To define a material for a solid, shell, or beam, right-click its icon in the COSMOS AnalysisManager tree and select Apply/Edit Material. Note that density is a required material property.
Define restraints if desired. The FFEPlus solver detects rigid body modes automatically and. If you set the solver option to FFEPlus or Automatic, you do not have to define any restraints. Rigid body modes are not counted among the requested number of modes. For example, if you ask for five modes for an unsupported solid model, FFEPlus extracts six rigid body modes in addition to the five requested modes. If you use the Direct Sparse solver, you must apply adequate restraints to stabilize your model or activate the Use soft spring to stabilize model option. However, note that restraints have a direct effect on the modes.
Define loads if desired. Loads are not required but are used if defined. The Direct Sparse solver is required to solve frequency problems with defined loads. Note that you can define thermal and fluid loading by right-clicking the study icon, selecting Properties, and clicking the Flow/Thermal Effects tab.
For assemblies and multibody
parts make sure to define the proper contact settings. Contact conditions
other than free and bonded are not allowed in frequency studies.
Mesh the model and run the study. Before running the study, you can use the Result Options to request generating plots for all mode shapes automatically.
If you run a study before
meshing it, the program meshes the study automatically before running
it. You can also request to run the study by checking Run
analysis after meshing in the Mesh
PropertyManager.
View the results:
Double-click an icon in a results folder to display the associated plot.
Right-click the Results folder and select List Resonant Frequencies to list the requested number of resonant frequencies in addition to any rigid body modes.
Right-click the Results folder and select List Mass Participation to list the mass participation of the calculated modes.
To define a new displacement plot, right-click the Results folder and select Define Displacement Plot .
To define a new deformation plot, right-click the Results folder and select Define Deformation Plot .
To animate an active plot, right-click its icon or right-click in the graphics area and select Animate.
To generate a report, right-click the Report folder and select Define.
Click here for more result viewing options.
When you run a study that
does not have any result folders, the software creates the folders and
plots specified in the result options for the study type. If result folders
are present, the software updates the existing plots.