How can I find the peak result of a combination of two harmonic analyses?


The most rigorous way to obtain the peak value of the combined result
is to check every possible phase angle combination between the two excitations.
That would require a lot of expansion passes, but they tend to run quickly.

The input below shows how you could do this. To be accurate you would need to
check at closer intervals than the 30 degrees used in this input file. The number
of solutions is (360/interval)^2, which could be prohibitive. You could assume that
the maximum combined result is the sum of the maximums in which case you only
need to solve 2*(360/interval) times.

/prep7
et,1,42
mp,ex,1,1e7
mp,nuxy,1,.3
mp,dens,1,.00025
rect,,20,,1
esize,.5
amesh,1
nsel,s,loc,x,0
d,all,all
nsel,all
fini

/solu
antype,modal
modop,lanb,10
mxpand,10
solve
fini

/solu
antyp,harm
hropt,msup
dmprat,.02
harf,,90
nsub,1
nsel,s,loc,x,20
f,all,fx,100
nsel,all
solve
harf,,100
fdele,all,all
nsel,s,loc,x,20
f,all,fy,20
nsel,all
solve
fini

/solu
expass,on
numexp,all
solve
fini

/post1
set,list
*do,iii,30,360,30
*do,jjj,30,360,30
/gopr

hrcplx,1,1,iii
lcwrite,99,ls1,lc99
hrcplx,1,2,jjj
lcfile,99,ls1,lc99
lcoper,add,99

! Retrieve max displacement
nsort,u,sum
*get,U_max,sort,,max
*get,Node_max,sort,,imax
*enddo
*enddo





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