{"id":241401,"date":"2022-11-19T12:00:38","date_gmt":"2022-11-19T12:00:38","guid":{"rendered":"\/forum\/forums\/topic\/no-mode-selected-for-combination-psd-analysis\/"},"modified":"2022-11-19T12:00:38","modified_gmt":"2022-11-19T12:00:38","slug":"no-mode-selected-for-combination-psd-analysis","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-mode-selected-for-combination-psd-analysis\/","title":{"rendered":"NO MODE SELECTED FOR COMBINATION – PSD ANALYSIS"},"content":{"rendered":"

Hello everyone. I’m having some difficulties performing a PSD analysis in Ansys APDL. I have a steel structure and a steel box, joined toghether with 4 brackets. This structure performed a vibrational test according to the MIL-STD-810. The PSD spectrum is the following (blue one) with 176lbs of weight on the box. After I perform the PSD analysis, I have to combine the extracted modes, but the software tells me that no mode were combined, because the partecipation factor must be calculated firts, but I used the command “pfact,1,base” on the code. Can someone help me?<\/p>\n

<\/p>\n

!Aree rinforzi cassetta<\/div>\n
a,25,42,43,21        !A14<\/div>\n
a,24,25,42,56,57,60,61,44    !A15<\/div>\n
a,24,44,45,20        !A16<\/div>\n
a,20,21,43,67,66,71,70,75,74,45    !A17<\/div>\n
 <\/div>\n
!Aree cerinere<\/div>\n
a,56,57,58,59  !A18 <\/div>\n
a,60,61,62,63  !A19<\/div>\n
a,64,65,66,67  !A20<\/div>\n
a,68,69,70,71  !A21<\/div>\n
a,72,73,74,75  !A22<\/div>\n
 <\/div>\n
!Area coperchio<\/div>\n
a,76,59,58,63,62,77,78,73,72,69,68,65,64,79  !A23<\/div>\n
!Aree rinforzo coperchio<\/div>\n
a,76,59,58,63,62,77,81,80      !A24<\/div>\n
a,77,81,82,78          !A25<\/div>\n
a,82,83,79,64,65,68,69,72,73,78      !A26<\/div>\n
a,76,79,83,80          !A27<\/div>\n
 <\/div>\n
!Tipologia elementi,materiali e sezioni<\/div>\n
et,1,beam188,,,3        !Beam 188 con f.f. cubica<\/div>\n
mp,ex,1,E          !Modulo Young material 1<\/div>\n
mp,nuxy,1,ni        !Coeff poisson material 1<\/div>\n
mp,dens,1,rho        !Densità material 1<\/div>\n
sectype,1,beam,hrec,tubquad    !Sezione tubolare quad<\/div>\n
secdata,wh1,wh1,th1,th1,th1,th1  !Dati sezione tubolare quad<\/div>\n
sectype,2,beam,chan,upn160    !Sezione upn160<\/div>\n
secdata,wu1,wu1,wu2,tu1,tu1,tu2  !Dati sezione upn 160<\/div>\n
sectype,3,beam,rect,staffa    !Sezione staffe<\/div>\n
secdata,bb,bh        !Dati sezione staffe<\/div>\n
et,2,shell63        !Shell63 cassetta<\/div>\n
mp,ex,2,E1          !Modulo Young material 2<\/div>\n
mp,nuxy,2,ni        !Coeff Poisson material 2<\/div>\n
mp,dens,2,rho1        !Densità material 2<\/div>\n
r,1,tc          !Spessore dello shell<\/div>\n
r,2,ws          !Spessore dello Shell delle staffe<\/div>\n
r,3,wcer          !Spessore cerniere<\/div>\n
mp,ex,3,E2          !Modulo di Young material 3 ABS<\/div>\n
mp,nuxy,3,ni2      !Coeff di Poisson material 3 ABS<\/div>\n
mp,dens,3,rho2        !Densità ABS<\/div>\n
r,4,tc,0,0,0,0,0,0,<\/div>\n
rmore,0,0,0,<\/div>\n
rmore<\/div>\n
rmore,mua<\/div>\n
 <\/div>\n
 <\/div>\n
!Meshing<\/div>\n
 <\/div>\n
!Mesh telaio<\/div>\n
esize,0.05<\/div>\n
lsel,r,line,,1,28<\/div>\n
latt,1,,1,,,,1  <\/div>\n
lmesh,all<\/div>\n
lsel,all<\/div>\n
 <\/div>\n
lsel,r,line,,30,32<\/div>\n
latt,1,,1,,,,1<\/div>\n
lmesh,all<\/div>\n
lsel,all<\/div>\n
 <\/div>\n
lsel,r,line,,29<\/div>\n
k,1000,,-1e+12<\/div>\n
latt,1,,1,,1000,,2<\/div>\n
lmesh,all<\/div>\n
lsel,all<\/div>\n
 <\/div>\n
!Mesh staffe<\/div>\n
esize,0.02<\/div>\n
lsel,r,line,,33,40<\/div>\n
latt,1,,1,,,,3<\/div>\n
lmesh,all<\/div>\n
lsel,all<\/div>\n
 <\/div>\n
!Mesh cassetta<\/div>\n
 <\/div>\n
asel,r,area,,7<\/div>\n
type,2<\/div>\n
real,4<\/div>\n
mat,2<\/div>\n
amesh,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
 <\/div>\n
asel,s,area,,1,6<\/div>\n
type,2<\/div>\n
real,1<\/div>\n
mat,2<\/div>\n
amesh,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
asel,s,area,,6,17<\/div>\n
type,2<\/div>\n
real,1<\/div>\n
mat,2<\/div>\n
amesh,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
asel,s,area,,23,27<\/div>\n
type,2<\/div>\n
real,1<\/div>\n
mat,2<\/div>\n
amesh,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
!Mesh chiusure<\/div>\n
asel,s,area,,18,19<\/div>\n
type,2<\/div>\n
real,3<\/div>\n
mat,3<\/div>\n
amesh,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
!Mesh cerniere in alluminio<\/div>\n
asel,s,area,,20,22<\/div>\n
type,2<\/div>\n
mat,2<\/div>\n
real,3<\/div>\n
amesh,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
 <\/div>\n
\/eshape,1,1<\/div>\n
eplo<\/div>\n
 <\/div>\n
 <\/div>\n
!vincoli<\/div>\n
ksel,r,kp,,1,4,1<\/div>\n
nslk,r,n,all<\/div>\n
d,all,all<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
!Carichi<\/div>\n
allsel,all<\/div>\n
 <\/div>\n
 <\/div>\n
!ANALISI SPETTRALE<\/div>\n
 <\/div>\n
\/solu<\/div>\n
antype,modal,new<\/div>\n
modopt,lanb,all,10,500<\/div>\n
mxpand,,,,yes,,,<\/div>\n
allsel,all<\/div>\n
outres,all,all<\/div>\n
outpr,all,all<\/div>\n
save<\/div>\n
solve<\/div>\n
finish<\/div>\n
 <\/div>\n
\/solu<\/div>\n
antype,spectrum,new<\/div>\n
spopt,psd,alles,no<\/div>\n
!EFINIZIONE SPETTRO DI RISPOSTA DELLA STRUTTURA<\/div>\n
PSDUNIT,1,accg,9.81<\/div>\n
psdfrq,1,,10,40,500<\/div>\n
psdval,1,0.078,0.078,0.0078<\/div>\n
sed,0.0,1.0,0.0<\/div>\n
allsel,all<\/div>\n
pfact,1,base<\/div>\n
psdres,disp,abs<\/div>\n
psdres,velo,abs<\/div>\n
psdres,acel,abs<\/div>\n
allsel,all<\/div>\n
outres,all,all<\/div>\n
outpr,all,all<\/div>\n
save<\/div>\n
solve<\/div>\n
finish<\/div>\n
 <\/div>\n
! ANALISI MODALE PER ESPANDERE I MODI ESTRATTI<\/div>\n
\/solu<\/div>\n
antype,spectr<\/div>\n
psdcom,,,,total<\/div>\n
solve<\/div>\n
 <\/div>\n
 <\/div>\n
\/post1<\/div>\n
set,last<\/div>\n
plnsol,s,eqv<\/div>\n
 <\/div>\n
 <\/div>\n
path,plot,25<\/div>\n
ppath,1,509<\/div>\n
*do,i,2,24<\/div>\n
ppath,i,550+i<\/div>\n
*enddo<\/div>\n
ppath,25,551<\/div>\n
pdef,sigma,s,eqv<\/div>\n
plpath,sigma<\/div>\n","protected":false},"template":"","class_list":["post-241401","topic","type-topic","status-closed","hentry","topic-tag-psd"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["249415","23687"],"_bbp_author_ip":["96.7.74.191"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["825"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["241401"],"_bbp_forum_id":["27791"],"_bbp_engagement":["23687","249415"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["241524"],"_bbp_last_active_id":["241524"],"_bbp_last_active_time":["2022-11-21 13:47:30"]},"test":"v-giordano3studenti-poliba-it"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/241401","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/241401\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=241401"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}