Mechanical APDL Structural Analysis Guide

2. Choose the save option you want and click on OK.

You have completed this example analysis.

6.4. Example Spectrum Analysis (Command or Bat ch Method)

You can perform the example spectrum analysis using the Mechanical APDL commands shown below
instead of GUI choices. Items prefaced by an exclamation point (!) are comments.

6.4.1. Single Point Response Spectrum Analysis on a Beam Structure

/prep7

/title seismic response of a beam structure

et,1,beam188

keyopt,1,3,3

sectype,1,beam,rect

secdata,71.6,3.82

mp,ex,1,30e6

mp,prxy,1,0.30

mp,dens,1,73e-5

k,1

k,2,240

k,3,0,1,0! define orientation keypoint

l,1,2

esize,,8

latt,,,,,,3! use orientation keypoint

lmesh,1

nsel,s,loc,x,0

dsym,symm,z

d,all,uy

nsel,s,loc,x,240

d,all,ux,,,,,uy

nsel,all

finish

/solu

antype,modal! mode-frequency analysis

modopt,lanb,3! block lanczos, extract first 3 modes

mxpand,1,,,yes! expand first mode shape, calculate element stresses

outpr,basic,1

solve

finish

/solu

antype,spectr! spectrum analysis

spopt,sprs! single point spectrum

sed,,1! global y-axis as spectrum direction

svtyp,3! seismic displacement spectrum

freq,.1,10! frequency points for sv vs. freq. table

sv,,.44,.44! spectrum values associated with frequency points

srss,0.15,disp! square root of sum of squares mode combination

! with signif=0.15 and displacement solution requested

solve

finish

/post1

set,list

/inp,,mcom

prnsol,dof! print nodal solution

prrsol,f! print reaction solution

finish

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

Spectrum Analysis