How can I make a strain energy distribution plot for a PSD analysis? We tried using an ETABLE item with (ETABLE,name,SENE), but we could not plot it.
Not all the usual result quantities are available after a psd analysis. Only the component displacements and stresses are available. Derived quantities like strain energy are not available because they cannot be computed from the unsigned one-sigma component results. An approximate method is to perform a /POST1 ETABLE combination of the modal results factored by the PSD modal coefficients. Here is an example. Since the variance retrieved with *GET is the square of the mode coefficient and the strain energy is a product of stress and strain, the *GET value can be used directly since the mode coefficient needs to be applied twice. /prep7 et,1,42 mp,ex,1,1e7 mp,nuxy,1,.3 mp,dens,1,.00025 rect,,20,,1.5 esize,1 amesh,1 nsel,s,loc,x,0 d,all,all nsel,all fini /solu antyp,modal modop,lanb,5 mxpand,5,,,yes solve fini /solu antyp,spectrum spopt,psd,,yes psdfrq,1,,1,1000 psdval,1,1,1 nsel,s,loc,x,0 d,all,uy,1 nsel,all pfact,1 psdcom solve fini /post1 *get,q11,mode,1,mcoef *get,q22,mode,2,mcoef *get,q33,mode,3,mcoef set,1,1 etab,sene_m1,sene etab,volu,volu sexp,send_m1,sene_m1,volu,1,-1 set,1,2 etab,sene_m2,sene sexp,send_m2,sene_m2,volu,1,-1 set,1,3 etab,sene_m3,sene sexp,send_m3,sene_m3,volu,1,-1 sadd,send_tot,send_m1,send_m2,q11,q22 ! add modes 1 and 2 sadd,send_tot,send_tot,send_m3,1,q33 ! add mode 3 to total pretab,send_tot |
||
|