各位帮我看看这段程序哪里有问题？（梁上移动质量弹簧单元瞬态分

yaoyaomao

fini$/cle$/config,nres,8000$/prep7 !初始参数设置 l=3$tf=0.272$bf=0.3$ff=0.5$b=1.2$b1=1$b2=1$h=0.3
el=0.2$ne=l/el$nd=ne+1
p=100000$v=20*1e3/3600$dt=el/v
kstif=1e20
!质量单元
et,1,mass21$r,1,,p/9.8 type,1$real,1
*do,i,1,nd$n,i,b2/2,h+0.02,(i-1)*el$e,i$*enddo !建立小箱梁模型 wprota,,90$blc4,,,b2,l$wpoffs,,,-h$wpoffs,-(b-b2)/2
blc4,,,b,l$blc4,,,-b1,l$agen,2,3,,,b+b1
nummrg,all$numcmp,all a,7,3,2,6$a,8,4,1,5
wpcsys
et,2,shell63
mp,ex,2,3.55e8$mp,prxy,2,0.2$mp,dens,2,2.6e3
r,2,tf$r,3,bf$r,4,ff
asel,s,loc,y,h$aatt,2,2,2 asel,s,loc,y,0$aatt,2,3,2
asel,a,loc,y,h$asel,inve$aatt,2,4,2
allsel,all
!加简支约束
lsel,s,loc,z,0$lsel,r,loc,y,0 dl,all,,ux$dl,all,,uy$dl,all,,uz$dl,all,,rotz
allsel,all
lsel,s,loc,z,l$lsel,r,loc,y,0 dl,all,,ux$dl,all,,uy$dl,all,,rotz allsel,all !划分网格 lesize,all,0.2 mshape,0$mshkey,1
amesh,all
*dim,br,,nd
*do,i,1,nd$br(i)=node(b2/2,h,(i-1)*el)$*enddo
！弹簧单元
et,3,14$r,5,kstif type,3$real,5
*do,i,1,nd$e,i,br(i)$*enddo
！瞬态分析
/solu$antype,4$nlgeom,off
nropt,full
nsel,s,,,1,nd$esln$ekill,all$d,all,all$allsel,all
timint,on
outres,all,none$outres,nsol,all deltim,dt/10$kbc,1$autots,on alphad,0.3361$betad,0.0047
ealive,1$ddele,1,all time,dt$solve
  *do,j,2,nd
  ekill,j-1$d,j-1,all$ealive,j$ddele,j,all   time,j*dt   solve   *enddo ekill,nd$d,nd,all$allsel,all time,nd*dt+0.02$solve
！后处理
/post26
nc=node(b2/2,h,l/3)
nsol,2,nc,u,y
plvar,2
出现很多下面的警告，结果也都是0：
*** WARNING ***   SUPPRESSED MESSAGE    CP =      54.734   TIME= 14:37:01
There are 2 small equation solver pivot terms.                          
*** WARNING ***   SUPPRESSED MESSAGE    CP =      54.812   TIME= 14:37:01
The calculated reference FORCE CONVERGENCE VALUE = 0 is less than 1E-2  
a threshold zero, A value of 1E-2 or specified MINREF is used.  Check   
results carefully.      
大家帮我看看这段小程序哪里有问题，怎么修正？