Can you limit the expansion of modes to only those modes with a high participation factors by using the MXPAND,,,,,,.01,,MODM command to ignore modes below a certain modal mass fraction?
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June 6, 2022 at 9:58 am
FAQ
ParticipantYes, but you have to do the modal expansion is a separate solution pass as shown in the following input.
/prep7
et,1,185,,2
mp,ex,1,1e7
mp,nuxy,1,.3
mp,dens,1,.0003block,,20,,2,,1
esize,1
vmesh,1
nsel,s,loc,x,0
d,all,all
nsel,all
fini
! Obtain the Modal Solution
/solu
antype, MODAL
modopt, LANB,12 ! Block Lanczos
solve
finish! Perform the modal selection and expansion
/solu
antype, MODAL, RESTART
mxpand,,,, yes,,, MODM ! Mode selection is based on the modal effective mass, and element
! results are requested
modseloption,no, no,0.90, no,no,no ! Only direction X is selected, a minimum of 90% of the total
! mass is requested in this direction
solve
finish
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