最近做一个类似于桩土分析的面面接触，但是总是收敛不了，出现的错误信息主要有以下有几种：
*** WARNING *** SUPPRESSED MESSAGE CP = 1978.922 TIME= 15:32:12
There are 7327 small equation solver pivot terms.
*** ERROR *** SUPPRESSED MESSAGE CP = 1978.938 TIME= 15:32:12
The value of UX at node 204 is 1.89968808E+09. It is greater than the
current limit of 1000000. This generally indicates rigid body motion
as a result of an unconstrained model. Verify that your model is
properly constrained.
*** ERROR *** SUPPRESSED MESSAGE CP = 1978.938 TIME= 15:32:12
*** MESSAGE CONTINUATION ---- DIAGNOSTIC INFORMATION ***
If one or more parts of the model are held together only by contact
verify that the contact surfaces are closed. You can check contact
status in the SOLUTION module for the converged solutions using
CNCHECK.
*** ERROR *** SUPPRESSED MESSAGE CP = 1978.938 TIME= 15:32:12
*** MESSAGE CONTINUATION ---- DIAGNOSTIC INFORMATION ***
Rigid body motion can also occur when net section yielding has
occurred resulting in large displacements for small increments of load
or when buckling has occurred. You can plot the time history curve
for node 204 in the UX direction to check for stiffness (slope of the
curve) approaching zero.
*** WARNING *** SUPPRESSED MESSAGE CP = 1740.141 TIME= 15:26:03
Contact element 4948 (real ID 10) status changes abruptly from contact
(with target element 4894) -> no-contact.
*** ERROR *** SUPPRESSED MESSAGE CP = 1184.641 TIME= 15:07:15
One or more elements have become highly distorted. Excessive
distortion of elements is usually a symptom indicating the need for
corrective action elsewhere. Try incrementing the load more slowly
(increase the number of substeps or decrease the time step size). You
may need to improve your mesh to obtain elements with better aspect
ratios. Also consider the behavior of materials, contact pairs,
and/or constraint equations. If this message appears in the first
iteration of first substep, be sure to perform element shape checking.
原始的命令流文件如下：
FINISH
/CLEAR
/title,Endbeam
/replot
/COM, Structural
/units,si !国际单位制
/prep7
!---------------------------------------------------------------------------------
! Para.
!---------------------------------------------------------------------------------
!------扣件间距
s=0.600
!------道床板尺寸参数
TCL_L=5 !m
TCL_W=2.8
TCL_H=0.260
!------支承层尺寸参数
BL_L=5 !m
BL_W=TCL_W
BL_H=0.3
!------端梁尺寸参数
EB_L1=1.4 !mEB_L2=0.8
EB_W=TCL_W
EB_H1=1.3
EB_H2=1.0
!------土体尺寸参数
GR_L1=9*EB_L2 !m
GR_L2=10*EB_L2
GR_W=3*EB_W
GR_H1=4*EB_H2
!------混凝土参数
C40_E=3.4e10 !Pa
C15_E=2.2e10 !参照GB2002
C_prxy=0.2
C_dens=2500 !kg/m3
!------温度力
TCL_A=TCL_W*TCL_H
T=35 !最大温差
a=1e-5 !混凝土线膨胀系数
k=0.3 !折减系数
Pres0=k*C40_E*a*T
TCL_F=k*C40_E*a*T*TCL_A
Pres1=TCL_F/(TCL_A+BL_W*BL_H)
!---------------------------------------------------------------------------------
! E.Type, Real Const., Material model
!---------------------------------------------------------------------------------
/PREP7
!------E.Type
ET,1,plane42 !用于拉伸的单元
ET,2,solid45
!------Real Const !plane42及solid45单元不用设置
!------Material model
!道床板及端梁
MP,ex,1,C40_E
MP,PRXY,1,C_prxy !主泊松比
MP,DENS,1,C_dens
!支承层
MP,ex,2,C15_E
MP,PRXY,2,C_prxy
MP,DENS,2,C_dens
!土体
mp,ex,3,2.5e8
mp,nuxy,3,0.4 !小泊松比
mp,dens,3,2000
tb,dp,3 !土体本够模型为D-P材料
tbdate,1,19000,40,0 !粘聚力19kpa，内摩擦角40度，膨胀角设为0
!---------------------------------------------------------------------------------
! geom & Mesh
!---------------------------------------------------------------------------------
/prep7
TYPE,1
!----------------------------------创建端梁
!关键点
k,1,-EB_L1/2,EB_H1,0
k,2,-EB_L2/2,EB_H1,0
k,3,-EB_L2/2,EB_H2,0
k,4,0,EB_H1,0
k,5,0,EB_H2,0
k,6,EB_L2/2,EB_H1,0
k,7,EB_L2/2,EB_H2,0
k,8,EB_L1/2,EB_H1,0
k,9,EB_L2/2,0,0
k,10,-EB_L2/2,0,0
k,11,
!定义面
a,1,2,3
a,2,4,5,3
a,4,6,7,5
a,6,8,7
a,3,5,11,10
a,5,7,9,11
!定义每条线段划分的段数，并网格划分
lsel,s,line,,1,11,
lesize,all,,,1
lsel,s,line,,13,16,3
lesize,all,,,1
lsel,s,line,,12,14,2
lsel,a,line,,15
lesize,all,,,4
TYPE,1
amesh,all
!沿z轴方向拉伸面生成体单元
TYPE,2 !使用体单元类型
mat,1
extopt,esize,2 !拉伸单元的划分次数
extopt,aclear,0 !先不删除原始的面网格
vext,all,,,,,-EB_W/2,,,,
extopt,esize,2
extopt,aclear,1 !删除原始的面网格
vext,1,6,1,,,EB_W/2,,,,
allsel
!------------------------------------创建道床板
!关键点
TYPE,1
k,101,-TCL_L,EB_H1+TCL_H,0 !定义关键点编号从100起
k,102,-TCL_L+0.2,EB_H1+TCL_H,0 !200=5000-600*8
*do,i,103,108,1
k,i,-TCL_L+0.2+(i-102)*s,EB_H1+TCL_H,0
*enddo
k,109,-EB_L1/2,EB_H1+TCL_H,0
k,110,-EB_L2/2,EB_H1+TCL_H,0
k,111,0,EB_H1+TCL_H,0
k,112,EB_L2/2,EB_H1+TCL_H,0
k,113,EB_L1/2,EB_H1+TCL_H,0
k,114,-TCL_L,EB_H1,0 !下层
k,115,-TCL_L+0.2,EB_H1,0
*do,i,116,121,1
k,i,-TCL_L+0.2+(i-115)*s,EB_H1,0
*enddo
!定义面
TYPE,1
*do,i,0,6,1
a,101+i,102+i,115+i,114+i
*enddo
a,108,109,1,121
a,109,110,2,1
a,110,111,4,2
a,111,112,6,4
a,112,113,8,6
!定义每条线段划分的段数，并网格划分
TYPE,1
lsel,s,line,,71,73,2
lesize,all,,,1
lsel,s,line,,75,93,3
lesize,all,,,2
lsel,s,line,,77,95,3
lesize,all,,,2
lsel,s,line,,96,102,1
lesize,all,,,1
lsel,s,line,,1,10,3
lesize,all,,,1
lsel,s,line,,72,76,2
lesize,all,,,1
lsel,s,line,,79,97,3
lesize,all,,,1
lsel,s,line,,99,101,2
lesize,all,,,1
lsel,s,line,,103
lesize,all,,,1
TYPE,1
amesh,51,62,1 !从图上读到的面号
!沿z轴方向拉伸面生成体单元
TYPE,2
mat,1
extopt,esize,2
extopt,aclear,0 !先不删除原始的面网格
vext,51,62,1,,,-TCL_W/2,,,,
extopt,esize,2
extopt,aclear,1 !删除原始的面网格
vext,51,62,1,,,TCL_W/2,,,,
allsel
!------------------------------------创建支承层
!关键点(下层)
TYPE,1
k,201,-BL_L,EB_H2,0 !定义关键点编号从200起
k,202,-BL_L+0.2,EB_H2,0
*do,i,203,208,1
k,i,-BL_L+0.2+(i-202)*s,EB_H2,0
*enddo
k,209,-BL_L+0.2+6*s+0.5,EB_H2,0
!定义面
*do,i,0,6,1
a,114+i,115+i,202+i,201+i
*enddo
a,121,1,209,208
a,1,3,209
!定义每条线段划分的段数，并网格划分
TYPE,1
lsel,s,line,,230,232,1
lesize,all,,,1
lsel,s,line,,233,247,2
lesize,all,,,1
lsel,s,line,,234,246,2
lesize,all,,,2
TYPE,1
amesh,161,169
!沿z轴方向拉伸面生成体单元
TYPE,2
mat,2
extopt,esize,2
extopt,aclear,0
vext,161,169,1,,,-TCL_W/2,,,,
extopt,esize,2
extopt,aclear,1
vext,161,169,1,,,TCL_W/2,,,,
!粘结体，将重合的节点，单元合并，重编号
allsel
vsel,s,,,all,
vplot
eslv,s
nslv,s,1
eplot
nummrg,all
numcmp,all
allsel
/pnum,area,1
/view,1,1,1,1
/ang,1
eplot
save
!-------------------------------------创建土体
!断面
TYPE,1
k,1001,EB_L2/2,EB_H2,0
k,1002,GR_L1+EB_L2/2,EB_H2,0
k,1003,GR_L1+EB_L2/2,0,0
k,1004,EB_L2/2,0,0
k,1005,GR_L1+EB_L2/2,-GR_H1,0
k,1006,EB_L2/2,-GR_H1,0
k,1007,0,-GR_H1,0
k,1008,0,0,0
k,1009,-EB_L2/2,-GR_H1,0
k,1010,-EB_L2/2,0,0
a,1001,1002,1003,1004
a,1004,1003,1005,1006
a,1004,1006,1007,1008
a,1008,1007,1009,1010
!网格
lsel,s,,,284,286,2
lesize,all,EB_L2/2
lsel,s,,,289,293,2
lesize,all,EB_L2/2
lsel,s,,,294,296,2
lesize,all,EB_L2/2
lsel,s,,,285,287,2
lesize,all,EB_H2/4
lsel,s,,,288,292,2
lesize,all,EB_H2/4
lsel,s,,,295
lesize,all,EB_H2/4
TYPE,1
amesh,216,219,1
!拉伸
TYPE,2
mat,3
extopt,esize,6
extopt,aclear,0
vext,216,219,1,,,-3*EB_W/2,,,,
extopt,esize,6
extopt,aclear,1
vext,216,219,1,,,3*EB_W/2,,,,
allsel
!设置接触单元
allsel !目标面
et,3,170
et,4,173
keyopt,4,9,0
keyopt,4,12,2
r,10 !r 10 表示定义10号实常数，这里实常数均为0
real,10 !real 10 表示一下单元的实常数为10号
mp,mu,3,0.2 !库伦摩擦系数
vsel,s,mat,,1
vplot
asel,s,,,27,28,
asel,a,,,49,50,
asel,a,,,24,46,22
aplot
cm,target,area
type,3
real,10
!mat,1
nsla,s,1
esurf,all
esel,s,type,,3
eplot
/psymb,esys,1
allsel
vsel,s,,,55,62,1 !接触面
vplot
asel,s,,,224,232,8
asel,a,,,241,249,8
asel,a,,,236,253,17
aplot
cm,contact,area
type,4
real,10
!mat,3
nsla,s,1
esurf,all
esel,s,type,,4
eplot
/psymb,esys,1
allsel
gplot
finish
!---------------------------------------------------------------------------------
! solu
!---------------------------------------------------------------------------------
!设置边界条件
/solu
asel,s,loc,x,GR_L1+EB_L2/2
aplot
da,all,all
asel,s,loc,z,3*EB_W/2
aplot
da,all,all
asel,s,loc,z,-3*EB_W/2
aplot
da,all,all
asel,s,loc,y,-GR_H1
aplot
da,all,all
allsel
asel,s,loc,x,-EB_L2/2
asel,r,loc,y,-GR_H1,0
aplot
da,all,all
allsel
asel,s,loc,y,1
asel,r,loc,x,-TCL_L,-EB_L2/2
aplot
da,all,UY
allsel
!施加重力加速度
acel,0,9.8,0
!在节点施加面荷载
nsel,s,loc,x,-TCL_L
sf,all,pres,Pres1
allsel
!设置分析/非线性选项求解
antype,static
nlgeom,on !包括几何非线性，及大变形效应
time,1 !指定荷载步结束时间 time,1
!DELTIM,0.1
nsubst,10,100,1 !指定此荷载步的子步数 ！nsubst 1的时候可算 !nsubst,10
neqit,50 !在非线性分析中指定平衡迭代的最大次数,在每个子步中允许平衡迭代的最大次数
!cnvtol,f,,0.05,2,0.01 !定义收敛条件,使用缺省的VALUE
outres,all,all !输出每一子步的结果
autots,on !使用自动时间步长
lnsrch,on !打开线性搜索
pred,on !打开预测器
!求解
allsel
solve
模型简图见附件
谢谢指教！
[ 本帖最后由 zhangyamin1984 于 2008-8-29 15:52 编辑 ] |
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发表于 2008-8-29 11:27:17
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