GUI:
Main Menu> Solution> Define Loads> Apply> Structural> Displacement> On lines
3.4.3.3. Listing Loads
To list existing loads, follow this GUI path:
GUI:
Utility Menu> List>Loads> load type
3.4.4. Specify Load Step Options.
The only load step options available for a modal analysis are damping options.
Table 3.4: Load Step Options (Damping)
Option Command
Global Alpha (mass) Damping ALPHAD
Global Beta (stiffness) Damping BETAD
Material-Dependent Alpha (mass) Damping MP,ALPD
Material-Dependent Beta (stiffness) Damp- MP,BETD,
ing
Element Damping (applied via element real R,TB
constant or material tables)
Material-Dependent Constant Structural MP,DMPR
Damping RatioDamping is valid only for the damped and QR damped mode-extraction methods. Damping is ignored
for the other mode-extraction methods. Constant structural damping ratio (MP,DMPR) is not supported
in a damped modal analysis (MODOPT,DAMP).
If you include damping and specify the damped mode-extraction method, the calculated eigenvalues
and eigenvectors are complex. If you include damping and specify the QR damped mode-extraction
method, the eigenvalues are complex, but the eigenvectors can be real or complex (Cpxmod on the
MODOPT command). The real eigenvectors are used for the mode-superposition analysis. See Comparing
Mode-Extraction Methods (p. 61) for details.
For more information about different forms of damping, see Damping (p. 2).
Damping specified in a non-damped modal analysis Damping (MP,DMPR) can be specified in a
non-damped modal analysis if a spectrum or mode-superposition analysis is to follow the modal analysis.
Although the damping does not affect the eigenvalue solution, it is used to calculate an effective
damping ratio for each mode, which is then used in the subsequent analysis; see the Mechanical APDL
Theory Reference.
3.4.5. Solve
Before you solve, save (SAVE) a backup copy of the database to a named file. You can then retrieve
your model by reentering the program and issuing RESUME.
Now start the solution calculations.
Command(s):SOLVE
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