Structural Dynamics

Structural Dynamics

Do you have any tests verifying force excitation PSD by comparison to the more common base excitation PSD?

    • SolutionSolution
      Participant

      SR 1323472733 Yes, the inputs below give the same solution for force and base excitation when one force is used. There’s no comparison possible when multiple forces are used. ! base excitation /prep7 et,1,188 mp,ex,1,1e7 mp,dens,1,.0003 mp,nuxy,1,.03 sectype,1,beam,rect secdata,.4,.2 et,2,21 r,2,1e6,1e6,1e6 n,1 n,11,20 fill e,1,2 *repe,10,1,1 d,1,all d,11,all fini /solu antype,modal modop,lanb,24 mxpand,all,,,yes solve fini /solu antype,spectrum spopt,psd,,yes d,1,uy,1 psdunit,1,acel psdres,disp,abs psdfrq,1,,1,10,100,1000 psdval,1,1000,1000,1000,1000 pfact,1 psdcom solve fini /post1 set,3,1 prdi prrsol etab,sbyt,smisc,32 etab,sbzt,smisc,34 pretab,sbyt,sbzt fini ! force excitation /prep7 et,1,188 mp,ex,1,1e7 mp,dens,1,.0003 mp,nuxy,1,.03 sectype,1,beam,rect secdata,.4,.2 et,2,21 r,2,1e6,1e6,1e6 n,1 n,11,20 fill e,1,2 *repe,10,1,1 type,2 real,2 e,1 d,1,all ddele,1,uy d,11,all fini /solu antype,modal modop,lanb,24 mxpand,all,,,yes solve fini /solu antype,spectrum spopt,psd,,yes f,1,fy,1e6 psdunit,1,forc psdfrq,1,,1,10,100,1000 psdval,1,1000,1000,1000,1000 pfact,1,node psdcom solve fini save /post1 set,3,1 prdi prrsol etab,sbzt,smisc,34 etab,sbyt,smisc,32 pretab,sbzt,sbyt

      Attachments:
      1. 2034964.zip