构建垫片法兰接触单元时提示错误

myblessing

小弟在构建法兰垫片接触单元时，垫片上的接触面可以正常构建接触单元，但是垫片上的接触单元却提示错误，不知道哪里出了问题，请各位朋友帮忙看下，谢谢
warning:
no surface elements were generated because no exterior face of the selected element set has all of its nodes selected!

myblessing

下面是命令流，情歌问帮帮忙啊，要不毕设就完了啊
!!!!!!!!!创建垫片与法兰接触单元!!!!!!!!
Allsel
Csys,5  !!激活以y为旋转轴的柱坐标系
Cmsel,s,flang_upvolu
Aslv
Asel,r,loc,z,0
Cm,fup1,area  !!上法兰接触面组件
Allsel
cmsel,s,gasketv
aslv
Asel,r,loc,z,0
cm,gasketup,area  !!垫片上接触面组件
Allsel

Cmsel,s,flang_dvolu
Aslv
Asel,r,loc,z,-gt
Cm,fdown1,area  !!下法兰接触面组件
Allsel
cmsel,s,gasketv
aslv
Asel,r,loc,z,-gt
cm,gasketd,area  !!垫片下接触面组件


Allsel
Et,8,targe170
Et,9,conta174
Keyopt,9,9,0
R,3
Real,3
Cmsel,s,fup1
Type,8
Nsla,s,1
Esln,s,0
Esurf,all   
Cmsel,s,gasketup
Type,9
Nsla,s,1
Esln,s,0
Esurf