Performing Frequency Analysis
To perform frequency analysis:
Create a frequency study. Right-click the top
icon in the Simulation study tree and select Properties.
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 Simulation study 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.
Related Topics
Frequency
Analysis
Mass
Participation
Output
of Frequency Analysis
Thermal Effects for Frequency
Studies