我现在想分析一下地下箱涵，我用的是beam3单元和combin14单元
但是我不知道如何在侧面施加梯形荷载 请高手指教一下
我的初步命令模型如下：
/prep7
et,1,beam3
et,2,combin14
r,1,0.5,0.0104666,0.5
r,2,100000000
mp,ex,1,3e10
mp,prxy,1,0.2
mp,dens,1,2500
k,1
k,2,4.7
k,3,4.7,5
k,4,,5
*do,i,1,3,1
l,i,i+1
*enddo
l,4,1
/pnum,line,1
lplot
esize,,10
mat,1
real,1
lmesh,all
nsel,s,loc,y,0
/pnum,node,1
nplot
NGEN,2,100,all,,,,-1,,1
ALLSEL,ALL
nsel,s,loc,y,5
ngen,2,100,all,,,,1,,1
allsel,all
/pnum,node,1
nplot
nsel,s,loc,x,0
ngen,2,100,all,,,-1,,,1
allsel,all
/pnum,node,1
nplot
nsel,s,loc,x,4.7
ngen,2,100,all,,,1,,,1
allsel,all
/pnum,node,1
nplot
n,200,0,-1
n,201,-1,-1
n,202,0,6
n,203,-1,6
n,204,4.7,-1
n,205,5.7,-1
n,206,4.7,6
n,207,5.7,6
nummrg,all
numcmp,all
type,2
mat,1
real,2
*do,i,3,11,1
e,i,i+40
*enddo
*do,i,13,21,1
e,i,i+40
*enddo
*do,i,23,31,1
e,i,i+40
*enddo
*do,i,32,40,1
e,i,i+40
*enddo
e,2,85
e,2,86
e,2,42
e,12,52
e,12,88
e,12,87
e,22,83
e,22,84
e,22,62
e,1,41
e,1,82
e,1,81
/SOL
nsel,s,loc,y,-1
/pnum,node,1
nplot
nsel,a,loc,x,-1
/pnum,node,1
nplot
nsel,a,loc,y,6
/pnum,node,1
nplot
nsel,a,loc,x,5.7
/pnum,node,1
nplot
D,all, , , , , ,UX,UY
allsel,all
eplot
*do,i,23,31,1
F,i,Fy,-164500
*enddo
*do,i,3,11,1
F,i,Fy,164500
*enddo
*do,i,32,40,1
F,i,Fx,70800
*enddo
*do,i,13,21,1
F,i,Fx,-70800
*enddo
SOLVE
/post1
etable,fx_i,smisc,1
etable,fx_j,smisc,7
etable,fy_i,smisc,2
etable,fy_j,smisc,8
etable,mz_i,smisc,6
etable,mz_j,smisc,12
plls,mz_i,mz_j,-1 !显示弯矩（1为显示比例)
plls,fx_i,fx_j,0.2 !显示轴力
plls,fy_i,fy_j,0.2 !显示剪力

里面的荷载没按真实的加，我想在两侧加梯形荷载，但是不知道这么加 请指教...谢谢