壳单元和实体单元接触问题

godfather

我先建一个面，然后制定它为壳体单元，厚度只有0.004m，在壳单元上下有土体，设置为实体单元，想请问高手，壳单元（一个面）能否和上下两个面设置接触对？我做了一下，老是有错误出现，我的命令流如下
finish
/clear
/prep7
/unit,si
fk1=0.1                     !法向接触刚度
fk2=0.1                     !法向接触刚度
fk3=0.1                     !法向接触刚度
fk4=0.1                     !法向接触刚度
ftoln=0.05                   !初始渗透因子

et,1,solid45
et,2,shell41
KEYOPT,2,1,2  
r,1,0.002,0.002,0.002,0.002,0,2e5
mp,ex,1,1.5e7        !材料属性
mp,dens,1,1800
mp,nuxy,1,0.35
tb,dp,1
tbdata,1,2.5e4,22,0
mp,ex,2,2e9
mp,prxy,2,0.3

k,1,11,0
k,2,-11,0
k,3,9.5,1
k,4,-9.5,1
a,1,2,4,3
lsel,s,,,1,3,2
lesize,all,,,20
lsel,s,,,2,4,2
lesize,all,,,5
amesh,1
！拉伸成体
extopt,esize,20,0
extopt,aclear,1
type,1
mat,1
vext,1,,,,,10
allsel

k,40,9.5,1
k,41,-9.5,1
k,42,9.5,1,10
k,43,-9.5,1,10
a,40,41,43,42
AATT, 2, 1, 2, 0,   
LESIZE,ALL, , ,20, ,1, , ,1, !!!定义单元边界长度  
MSHAPE,0,2D  
MSHKEY,1  
AMESH,all !!!三角划分面单元  

k,9,9.5,1
k,10,-9.5,1
k,11,6.5,3
k,12,-6.5,3
a,9,10,12,11
lsel,s,,,17,19,2
lesize,all,,,20
lsel,s,,,18,20,2
lesize,all,,,10
amesh,8
！拉伸成体
extopt,esize,20,0
extopt,aclear,1
type,1
mat,1
vext,8,,,,,10
allsel

k,44,6.5,3
k,45,-6.5,3
k,46,6.5,3,10
k,47,-6.5,3,10
a,44,45,47,46
AATT, 2, 1, 2, 0,   
LESIZE,ALL, , ,20, ,1, , ,1, !!!定义单元边界长度  
MSHAPE,0,2D  
MSHKEY,1  
AMESH,all !!!三角划分面单元  

k,17,6.5,3
k,18,-6.5,3
k,19,5,4
k,20,-5,4
a,17,18,20,19
lsel,s,,,33,35,2
lesize,all,,,20
lsel,s,,,34,36,2
lesize,all,,,5
amesh,15
！拉伸成体
extopt,esize,20,0
extopt,aclear,1
type,1
mat,1
vext,15,,,,,10
allsel
/view,1,1,1,1
eplot


allsel
et,3,170
et,4,173
R,2,,,FK1,FTOLN,-0.002,0
RMORE,,,1e20,0,1.0,
RMORE,0.0,0,1.0,,1.0,0.5
RMORE,0,1.0,1.0,0.0,0,1.0  
R,3,,,FK2,FTOLN,-0.002,0
RMORE,,,1e20,0,1.0,
RMORE,0.0,0,1.0,,1.0,0.5
RMORE,0,1.0,1.0,0.0,0,1.0  
R,4,,,FK3,FTOLN,-0.002,0
RMORE,,,1e20,0,1.0,
RMORE,0.0,0,1.0,,1.0,0.5
RMORE,0,1.0,1.0,0.0,0,1.0  
R,5,,,FK4,FTOLN,-0.002,0
RMORE,,,1e20,0,1.0,
RMORE,0.0,0,1.0,,1.0,0.5
RMORE,0,1.0,1.0,0.0,0,1.0  


keyopt,4,4,1              !接触法向垂直于接触表面
keyopt,4,5,1            
keyopt,4,9,2            
keyopt,4,10,0            
keyopt,4,12,2

mp,mu,1,0.2               !动态摩擦系数

asel,s,,,7
aplot
cm,target1,area
type,3
real,2
nsla,s,1
esurf,all
esel,s,type,,3
eplot
/psymb,esys,1
allsel

allsel,all
vsel,s,,,1
aslv,s
asel,s,,,5
aplot
cm,contact1,area
type,4
real,2
nsla,s,1
esurf,all
esel,s,type,,4
eplot
/psymb,esys,1
allsel

asel,s,,,7
aplot
cm,target2,area
type,3
real,3
nsla,s,1
esurf,all
esel,s,type,,3
eplot
/psymb,esys,1
allsel

allsel,all
vsel,s,,,2
aslv,s
asel,s,,,10
aplot
cm,contact2,area
type,4
real,3
nsla,s,1
esurf,all,bottom
esel,s,type,,4
eplot
/psymb,esys,1
allsel

asel,s,,,14
aplot
cm,target3,area
type,3
real,4
nsla,s,1
esurf,all
esel,s,type,,3
eplot
/psymb,esys,1
allsel

allsel,all
vsel,s,,,2
aslv,s
asel,s,,,12
aplot
cm,contact3,area
type,4
real,4
nsla,s,1
esurf,all
esel,s,type,,4
eplot
/psymb,esys,1
allsel

asel,s,,,14
aplot
cm,target4,area
type,3
real,5
nsla,s,1
esurf,all
esel,s,type,,3
eplot
/psymb,esys,1
allsel

allsel,all
vsel,s,,,3
aslv,s
asel,s,,,17
aplot
cm,contact4,area
type,4
real,5
nsla,s,1
esurf,all,bottom
esel,s,type,,4
eplot
/psymb,esys,1
allsel
gplot
save
finish


!求解过程
/solu
asel,s,loc,y,0
da,all,all,0

asel,all
sfa,19,,pres,1000
alls
acel,0,9.8,0


!设置非线性选项
antype,static
nropt,full
time,1
auto,on
pred,on
lnsrch,on
outpr,all,all   !控制分析后的结果显示于输出窗口中
outres,all,all  !规定写入数据库的求解信息
nsubst,10,20,5

allsel,all
cncheck,detail  !检查接触状态
cncheck,summary

solve
!finish


*** NOTE ***                            CP=     19.000   TIME= 11:33:32
Smoothing on certain contact nodes (e.g.27) may have accuracy issue.   
Please verify element normal of connected contact elements              
(e.g.12001&12800).                                                      

*** NOTE ***                            CP=     19.016   TIME= 11:33:32
Smoothing on certain contact nodes (e.g.3550) may have accuracy issue.  
  Please verify element normal of connected contact elements            
(e.g.13201&13999).                                                      

*** NOTE ***                            CP=     19.031   TIME= 11:33:32
Smoothing on certain contact nodes (e.g.3119) may have accuracy issue.  
  Please verify element normal of connected contact elements            
(e.g.14401&15200).                                                      

*** NOTE ***                            CP=     21.984   TIME= 11:33:35
Deformable-deformable contact pair identified by real constant set 2   
and contact element type 4 has been set up.                             
Contact algorithm: Augmented Lagrange method
Contact detection at: nodal point (normal from contact nodes)

*** WARNING ***                         CP=     21.984   TIME= 11:33:35
Smoothing on certain contact/target nodes (e.g.27) may have an accuracy
issue.  You may switch contact and target sufaces, or split the         
current pair into multiple pairs, or use Gauss detection.               
Contact stiffness factor FKN                 0.10000   
The resulting contact stiffness              0.87888E+09
Penetration tolerance factor FTOLN           0.50000E-01
The resulting penetration tolerance          0.11387E-01
Opening contact stiffness factor KFOP         1.0000   
Max. initial friction coefficient MU         0.20000   
Default tangent stiffness factor FKT          1.0000   
Max. friction stress TAUMAX                  0.10000E+21
Average contact surface length               0.75911   
Average contact pair depth                   0.22773   
Default pinball region factor PINB            2.0000   
The resulting pinball region                 0.45547   
Default target edge extension factor TOLS     10.000   
User define initial closure ICONT            0.20000E-02
Auto contact offset used to close gap         0.0000   
Initial penetration will be ramped during the first load step.
No-separation contact is defined.

*** NOTE ***                            CP=     22.000   TIME= 11:33:35
No contact was detected for this contact pair.                          
****************************************
  

*** NOTE ***                            CP=     22.000   TIME= 11:33:35
Deformable-deformable contact pair identified by real constant set 3   
and contact element type 4 has been set up.                             
Contact algorithm: Augmented Lagrange method
Contact detection at: nodal point (normal from contact nodes)

*** WARNING ***                         CP=     22.000   TIME= 11:33:35
Smoothing on certain contact/target nodes (e.g.3550) may have an        
accuracy issue.  You may switch contact and target sufaces, or split   
the current pair into multiple pairs, or use Gauss detection.           
Contact stiffness factor FKN                 0.10000   
The resulting contact stiffness              0.87888E+09
Penetration tolerance factor FTOLN           0.50000E-01
The resulting penetration tolerance          0.11387E-01
Opening contact stiffness factor KFOP         1.0000   
Max. initial friction coefficient MU         0.20000   
Default tangent stiffness factor FKT          1.0000   
Max. friction stress TAUMAX                  0.10000E+21
Average contact surface length               0.75911   
Average contact pair depth                   0.22773   
Default pinball region factor PINB            2.0000   
The resulting pinball region                 0.45547   
Default target edge extension factor TOLS     10.000   
User define initial closure ICONT            0.20000E-02
Auto contact offset used to close gap         0.0000   
Initial penetration will be ramped during the first load step.
No-separation contact is defined.

*** NOTE ***                            CP=     22.047   TIME= 11:33:35
No contact was detected for this contact pair.                          
****************************************
  

*** NOTE ***                            CP=     22.062   TIME= 11:33:35
Deformable-deformable contact pair identified by real constant set 4   
and contact element type 4 has been set up.                             
Contact algorithm: Augmented Lagrange method
Contact detection at: nodal point (normal from contact nodes)

*** WARNING ***                         CP=     22.062   TIME= 11:33:35
Smoothing on certain contact/target nodes (e.g.3119) may have an        
accuracy issue.  You may switch contact and target sufaces, or split   
the current pair into multiple pairs, or use Gauss detection.           
Contact stiffness factor FKN                 0.10000   
The resulting contact stiffness              0.10574E+10
Penetration tolerance factor FTOLN           0.50000E-01
The resulting penetration tolerance          0.94644E-02
Opening contact stiffness factor KFOP         1.0000   
Max. initial friction coefficient MU         0.20000   
Default tangent stiffness factor FKT          1.0000   
Max. friction stress TAUMAX                  0.10000E+21
Average contact surface length               0.57987   
Average contact pair depth                   0.18929   
Default pinball region factor PINB            2.0000   
The resulting pinball region                 0.37858   
Default target edge extension factor TOLS     10.000   
User define initial closure ICONT            0.20000E-02
Auto contact offset used to close gap         0.0000   
Initial penetration will be ramped during the first load step.
No-separation contact is defined.

*** NOTE ***                            CP=     22.109   TIME= 11:33:35
No contact was detected for this contact pair.                          
****************************************
  

*** NOTE ***                            CP=     22.109   TIME= 11:33:35
Deformable-deformable contact pair identified by real constant set 5   
and contact element type 4 has been set up.                             
Contact algorithm: Augmented Lagrange method
Contact detection at: nodal point (normal from contact nodes)
Contact stiffness factor FKN                 0.10000   
The resulting contact stiffness              0.15354E+07
Penetration tolerance factor FTOLN           0.50000E-01
The resulting penetration tolerance          0.97692E-02
Opening contact stiffness factor KFOP         1.0000   
Max. initial friction coefficient MU         0.20000   
Default tangent stiffness factor FKT          1.0000   
Max. friction stress TAUMAX                  0.10000E+21
Average contact surface length               0.57987   
Average contact pair depth                   0.19538   
Default pinball region factor PINB            2.0000   
The resulting pinball region                 0.39077   
Default target edge extension factor TOLS     10.000   
User define initial closure ICONT            0.20000E-02
Auto contact offset used to close gap         0.0000   
Initial penetration will be ramped during the first load step.
No-separation contact is defined.

*** NOTE ***                            CP=     22.125   TIME= 11:33:35
Max.  Initial penetration 2.664535259E-15 was detected between contact  
element 15824 and target element 15272.                                 
****************************************
  

       4 CONTACT PAIRS ARE SELECTED
     CONTACT PAIR HAVING REAL ID =     2 IS INITIALLY OPEN
      BUT MAY BE AUTOMATICALLY CLOSED
     CONTACT PAIR HAVING REAL ID =     3 IS INITIALLY OPEN
      BUT MAY BE AUTOMATICALLY CLOSED
     CONTACT PAIR HAVING REAL ID =     4 IS INITIALLY OPEN
      BUT MAY BE AUTOMATICALLY CLOSED
     CONTACT PAIR HAVING REAL ID =     5 IS INITIALLY CLOSED

还有就是不收敛

godfather

想请高手帮我看一下，错在哪里？我搞了很久了，就是改不出来，心里很急，谢谢了

zhi217

I think it is the problem of contact pair, one surface only has one normal direction, it can not detect two target surfaces. I have met the same problem like you, I have no idea to do it, at the end, i change the shell element to solid element. this is what i can do.

babecheer

同问高手，壳单元（一个面）能否同时和上下两个面设置接触对？

sh_lin30

顶一下！

windsun.typ

版主怎么顶了一下呢？
据我所知，壳单元和梁单元好像都只能在一个面上设置接触对的。因为记得在壳单元中设置接触对是要指定是壳的内法线还是外法线方向的，如果两边都可以设置接触对的话应该是不存在这个指定方向的问题的。（例如在实体单元中指定接触方向时是“对2─D接触问题，当沿着目标线从第一个结点移向第二个结点时，变形体的接触单元必须位于目标面的右边。”，“对3─D接触问题，目标三角形单元号应该使刚性面的外法线方向指向接触面，外法线通过右手原则来义”）。请各位大虾或者版主现身证明一下小弟说得是否正确吧！谢谢！

windsun.typ

另外，我在使用梁单元的时候也出现了类似问题。我也是采用了类似zhi217兄台的处理方法，就是用实体单元。尚未有更好的解决办法。呵呵！

huanghui01

不是很清楚壳和实体单元之间的关系,是否能用耦合来解决你的问题,如果只考虑力的传递的话,我觉得可以用耦合

yangwenliang_24

用耦合太麻烦了，还是用接触好！用接触中的 绑定接触！

windsun.typ

楼主所问的是能否同时在壳单元的两个面同时设置接触单元。答案估计是否定的。
至于实体单元与壳单元之间的联系，要用耦合的方法了。

20052110

壳单元夹在实体网格中间，怎么处理呢？

原野05071515

同问，壳单元夹在实体网格中间~

monster_murphy

我遇到的是壳单元一面与壳单元接触
另一面与实体单元接触
不知道怎么模拟哦