本帖最后由 zchao 于 2011-7-31 14:21 编辑
问题背景:切刀向下运动切割塑性材料,采用plane162单元,切刀设置为刚体,接触类型为单面自动接触。负体积在计算一开始就出现,总是在左下角的约束单元上出现负体积,不管怎么约束都是那个单元出现负体积,请高手指点。错误信息如下:
*** Error negative volume in 2D solid element # 71 cycle 0
*** Warning negative volume in 2D solid element # 72 cycle 0
*** Warning negative volume in 2D solid element # 73 cycle 0
*** Warning negative volume in 2D solid element # 74 cycle 0
*** Warning negative volume in 2D solid element # 75 cycle 0
命令流文件如下:
finish
/clear
/filename,thermalcut
/title,thermalcut
/prep7
!*定义单元类型
et,1,plane162
keyopt,1,3,1 !平面应变类型
!*定义切刀材料模型
edmp,rigi,1,4,7 !只有向下的平动自由度
mp,dens,1,10e-3
mp,ex,1,800e9
mp,nuxy,1,0.3
!*定义生瓷的材料模型
mp,dens,2,3.7e-3
mp,ex,2,150e9
mp,nuxy,2,0.3
tb,biso,2
tbdata,1,160e6
tbdata,2,60e9
!*建立切刀实体模型
k,2,0.002,0
k,3,-0.002,0
k,4,0.05,2
k,5,-0.05,2
k,6,0.09,6
k,7,-0.09,6
l,2,3
l,2,4
l,3,5
l,4,5
l,4,6
l,5,7
l,6,7
/pnum,line,1
lplot
al,1,2,3,4
al,4,5,6,7
allsel,all
aglue,all
allsel,all
agen,,all,,,,1,,,,1
!*建立生瓷实体模型
rectng,-10,3,-3,0
!*控制单元尺寸
/pnum,line,1
lplot
lesize,1,,,1
lesize,2,,,40,20
lesize,3,,,40,20
lesize,5,,,30,10
lesize,6,,,30,10
lesize,4,,,1
!lesize,10,,,100
!lesize,9,,,40
!*切刀网格划分
mat,1
type,1
mshkey,1 !映射
amesh,1
amesh,2
mat,2
type,1
esize,0.05
mshkey,1 !映射
amesh,3
allsel,all
edpart,create !产生part
edasmp,add,5,1,2 !定义assembly
!*定义接触
edcgen,ass2d,5,, !定义接触类型,2d单面接触
edcontact,0.1,0,2,0,1,1,1,4,0 !接触控制参数?
!*定义约束
nsel,s,loc,x,-10
d,all,ux,0
d,all,uy,0
!nsel,s,loc,y,-3
!d,all,uy,0
allsel,all
!*定义初始速度
edpvel,velo,1,0,-10
finish
!*求解控制
/solu
allsel,all
edenergy,1,1,1,1 !能量控制
edbvis,1.5,0.06 !粘塑性系数,默认
edhgls,0.1
time,0.04
edcts,0,0.9 !时间步控制
edopt,add,blank,both !既可以在post1中也可以在ls-prepost中查看结果
edrst,20
edhtime,20 !结果输出间隔
eddump,1 !输出频率
solve
K文件见附件: |