Mechanical APDL Structural Analysis Guide

Damping in some form should be specified; otherwise, the response will be infinity at the resonant

frequencies.ALPHAD and BETAD result in a frequency-dependent damping ratio, whereas

DMPSTR specifies a constant structural damping coefficient.

Damping can also be specified for individual materials using MP,BETD,MP,ALPD, and MP,DMPR

or by using a viscoelastic material model. See Damping (p. 2) for more information.

If no damping is specified in a direct harmonic analysis (full harmonic), the program uses zero

damping by default.

• Alpha (Mass) Damping (ALPHAD)


• Beta (Stiffness) Damping (BETAD)


• Constant Structural Damping Coefficient (DMPSTR)


• Material Dependent (Mass) Damping Multiplier (MP,ALPD)


• Material Dependent (Stiffness) Damping Multiplier (MP,BETD)


• Constant Structural Material Damping Coefficient (MP,DMPR)


• Material Structural Damping Coefficient (TB,SDAMP)


• Viscoelastic Material Damping (TB,PRONY )

4.4.3.4.3. Output Controls

Output control options include the following:

• Printed Output(OUTPR)

Use this option to include any results data on the output file (Jobname.OUT).

• Database and Results File Output (OUTRES)

This option controls the data on the results file (Jobname.RST).

• Extrapolation of Results(ERESX)

Use this option to review element integration point results by copying them to the nodes instead

of extrapolating them (default).

4.4.3.5. Save a Backup Copy of the Database to a Named File

You can then retrieve your model by reentering the ANSYS program and issuing RESUME.

Command(s):SAVE
GUI: Utility Menu> File> Save as

4.4.3.6. Start Solution Calculations

Command(s):SOLVE
GUI: Main Menu> Solution> Solve> Current LS

Release 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information

Performing a Harmonic Analysis