怎么解決，我是用beam188單元模擬梁和柱，shell181模擬剪力墻，并且將他們的節(jié)點(diǎn)建立在一起，是不是不用建立約束方程或者耦合，但是不建立系統(tǒng)就這樣報(bào)錯(cuò)，怎么解決

finish
/clear
/prep7et,1,beam188
et,2,shell181
keyopt,2,3,2SECTYPE,1,BEAM,RECT
SECDATE,0.5,0.5
SECTYPE,2,BEAM,RECT
SECDATE,0.6,0.4
secoffset,user,0.3,0
MP,NUXY,1,0.2
MP,DENS,1,3000
mp,ex,1,32680e6
MP,NUXY,2,0.2
MP,DENS,2,3000
mp,ex,2,32680e6
r,2,0.2,0.2,0.2,0.2k,1
k,2,5
k,3,5,4
k,4,0,4
l,1,4
l,4,3
l,3,2
l,1,2lsel,s,line,,2
latt,1,,1,,,,2
lesize,2,1allsel,all
lsel,s,line,,1
latt,1,,1,,,,1
lesize,1,1allsel,all
lsel,s,line,,3
lesize,3,1
latt,1,,1,,,,1
allsel,all
lmesh,1,3,1/eshape,1
al,all
asel,s,area,,1
aatt,2,2,2
lesize,4,1
amesh,1
d,1,all
d,15,all
d,16,all
d,17,all
d,18,all
d,11,all/solu
d,6,ux,0.1
/post1
pldisp,1