Mechanical APDL Structural Analysis Guide

Option Command GUI Path

Main Menu> Solution> Load Step Opts>

Other> Change Mat Props> Material Mod-

els> Structural> Damping

MP,DMPR,

TB,SDAMP

MP,ALPD, Not accessible from the GUI.

MP,BETD,

Output Control Options

Main Menu> Solution> Load Step Opts>

Output Ctrls> Solu Printout

Printed Output OUTPR

Main Menu> Solution> Load Step Opts>

Output Ctrls> DB/ Results File

Database and Results File OUTRES

Output

Main Menu> Solution> Load Step Opts>

Output Ctrls> Integration Pt

Extrapolation of Results ERESX

When specifying frequency dependent damping using TB,SDAMP you must specify the material property
using TB,ELAS.

4.4.3.4.1. General Options.

General options include the following:

• Number of Harmonic Solutions(NSUBST)

You can request any number of harmonic solutions to be calculated. The solutions (or substeps)

will be evenly spaced within the specified frequency range (HARFRQ). For example, if you specify

10 solutions in the range 30 to 40 Hz, the program will calculate the response at 31, 32, 33, ...,

39, and 40 Hz. No response is calculated at the lower end of the frequency range.

• Stepped or Ramped Loads (KBC)

The loads may be stepped or ramped. By default, they are ramped, that is, the load amplitude

is gradually increased with each substep. By stepping the loads (KBC,1), the same load amplitude

will be maintained for all substeps in the frequency range.

Note

Surface and body loads do not ramp from their previous load step values. They always

ramp from zero or from the value specified via BFUNIF.

4.4.3.4.2. Dynamics Options.

Dynamics options include the following:

• Forcing Frequency Range (HARFRQ)

The forcing frequency range must be defined (in cycles/time) for a harmonic analysis. Within this

range, you then specify the number of solutions to be calculated.

• Damping

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

Harmonic Analysis