单跨井字梁计算结果跟井字梁计算手册对不上呢

finish
/clear
/prep7
et,1,beam188
mp,ex,1,30000
MP,PRXY,1,0.3
mp,dens,1,2.5e-9
r,1
et,2,shell63
mp,ex,2,30000
MP,PRXY,2,0.3
mp,dens,2,2.5e-9
r,2,120

sectype,1,beam,rectng
secdata,250,400
secoffset,user,0,260
sectype,2,beam,rectng
secdata,400,400

rectng,0,10000,0,7500
wprota,,,90
csys,4
wpoffs,,,2500
asbw,all
wpoffs,,,2500
asbw,all
wpoffs,,,2500
asbw,all

kwpave,1
wpoffs,,2500
wprota,,90
asbw,all
wpoffs,,,-2500
asbw,all

ksel,s,,,1,4
csys,0
KGEN,2,all,,,,,-3000

l,1,21
l,2,22
l,3,23
l,4,24

lsel,s,loc,z,0
LESIZE,all,100
LATT,1,,1,,,,1

allsel
lsel,u,loc,z,0
LESIZE,all,100
LATT,1,1,1,,,,2

allsel,all
asel,s,loc,z,0
aatt,2,2,2
amesh,all
lmesh,all

ksel,s,loc,z,-3000
dk,all,all

asel,s,loc,z,0
sfa,all,1,pres,-0.008

ACEL,,,9800
allsel,all

/solu
sbctran
solve
/post1
etable,mx,smisc,4,17
etable,my,smisc,2,15
etable,mz,smisc,3,16

plls,mx,mx,-1


弯矩相差很大 求大神指导下吧