Mechanical APDL Structural Analysis Guide

Example input to perform perturbed modal solve in a rotating reference frame:

/solution

antype, static! Static analysis

nlgeom, on! Non-linear analysis

rescontrol, define, all, 1! Define restart files

f,...! Define loads (for example nodal force)

omega,...! Define the rotational velocity

solve

finish

/solution

antype, static, restart, last, last, perturb! Do a linear perturbation analysis

perturb, modal,,, inerkeep! Perturbation modal (keep the inertial loads)

coriolis, on! Coriolis in a rotating reference frame

solve, elform! First Perturbation solve (form the stiffness matrix)

modopt, damp,...! Choose the eigensolver (for example DAMP)

mxpand, ...! Expand the solutions

solve! Second Perturbation solve (solve the eigenproblem)

finish

9.6. Example Inputs for Linear Perturbation Analysis

This section contains input listings for the following linear perturbation analysis examples:

Linear Perturbation Static Analysis

Simple Example of a Linear Perturbation Modal Analysis

Linear Perturbation Modal Analysis with Large Rotation Effects

Contact Status Control in a Linear Perturbation Modal Analysis

Prestressed QRDAMP Linear Perturbation Modal Analysis

Using Linear Perturbation to Predict a Buckling Load

Linear Perturbation (Prestressed) Harmonic Analysis

Example 9.1: Linear Perturbation Static Analysis

/prep7

et,1,solid185

mp,ex,1,11.5e8

mp,nuxy,1,.3

mp,dens,1,1000

! ********** Creating geometry ***********

block,0,1,0,-0.1,-1,1

esize,0.2

type,1

vmesh,1

block,1,2,0,-0.1,-1,1

esize,0.2

type,1

vmesh,2

allsel,all

! ********** Creating Bonded Contact Pair **********

*set,tid,4

*set,cid,3

et,cid,conta175

et,tid,targe170

keyo,cid,12,5! Bonded Contact

vsel,s,volu,,1

allsel,below,volu

type,3

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Linear Perturbation Analysis