Mechanical APDL Structural Analysis Guide

/com, ************************************************************

presol,cont,stat! Expected contact status: Sticking

esel,all

/cycexpand,,off

finish

Example 9.5: Prestressed QRDAMP Linear Perturbation MODAL Analysis

/filname,modal

pres1 = 500

k1 = 1.e+4

k2 = 1.e+2

/prep7

et,1,185,,2

mp,ex,1,3.0e5

mp,nuxy,1,.3

mp,dens,1,.05

mp,mu,1,.3! Make friction large

lp = 0.5

hp = 0.5

block,-lp,lp,-lp,lp, ,hp

block,-lp,lp,-lp,lp,hp,2*hp

esize,1.0

vmesh,1,2

!********** Allow sliding contact between blocks **********

et,2,174

et,3,170

keyopt,2,9,1

keyopt,2,10,1

r,3

type,2

real,3

vsel,s,,,1,,,1

nsel,r,loc,z,hp

esurf

type,3

vsel,s,,,2,,,1

nsel,r,loc,z,hp

esurf

alls

!********** Put springs on UX ***********

et,4,14

keyopt,4,2,1

r,4,k1

et,5,14

keyopt,5,2,1

r,5,k2

lsp = -hp/2

n,1000,-lp, lp,lsp

n,1001,-lp,-lp,lsp

n,1002, lp, lp,lsp

n,1003, lp,-lp,lsp

type,4

real,4

e,1000,node(-lp,lp,0)

e,1001,node(-lp,-lp,0)

e,1002,node(lp,lp,0)

type,5

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Example Inputs for Linear Perturbation Analysis