在实际做项目分析中，经常会遇到网格高度扭曲，让网格质量重新改进或者增加子步长，增加子步长可以解决一些变形不大的问题，改善网格是关键。
改善网格分两步：第一，对原始网格应该严格控制其长宽比在合适的范围，对于变形比较大的地方建议不要超过1:2，视实际情况网格数量而定可以适当增加或者降低。有时，对于网格变形比较大的情况，即便初始网格很好的比例，但是随着载荷的施加，局部的变形十分不协调，导致网格畸变。此时需要借助第二种网格改善方案，结合重启动技术和rezone重新画网格，重新画的网格是对变形后的区域进行的，所以能有效克服网格畸变的不收敛问题。
下面提供一个实例供大家参考：
/PREP7
H=169
H1=57.68
H2=1.6
H3=1.6
H4=5.6
H5=3.68
L=35
L1=25.8
L2=15.2
L3=29.8
L4=34.72
R1=8
R2=8
R3=8
R4=4
R5=4
ET,1,PLANE182
!*
KEYOPT,1,1,0
KEYOPT,1,3,1
KEYOPT,1,6,1
MP,EX,1,200E3
MP,PRXY,1,0.3
TB,NLIS,1,1,4,POWER
TBTEMP,0
TBDATA,,385.4,0.13,,,,
K,1,0,0,0
K,2,L,0,0
K,3,L,H,0
K,4,0,H,0
K,5,0,0,0
K,6,L,0,0
K,7,L,H3,0
K,8,L,H3+R3,0
K,9,L+R3+L3+R4,H3+R3,0
K,10,L+R3+L3+R4,-H5-R5,0
K,11,L+R1+L1+R2+L2,-H5-R5,0
K,12,L+R1+L1+R2+L2,H1-H5-R5,0
K,13,L+R1+L1+R2+L2+L4,H1-H5-R5,0
K,14,L+R1+L1+R2+L2,H,0
K,15,L+R1+L1+R2,H,0
K,16,L+R1+L1+R2,H-R2-H2,0
K,17,L,H-R1-H2,0
K,18,L,H-H2,0
K,19,L,H,0
K,20,0,H,0
A,1,2,3,4
L,5,6
L,6,7
L,7,8
L,8,9
L,9,10
L,10,11
L,11,12
L,12,13
L,14,15
L,15,16
L,16,17
L,17,18
L,18,19
L,19,20
LFILLT,16,15,R1, ,
LFILLT,15,14,R2, ,
LFILLT,7,8,R3, ,
LFILLT,8,9,R4, ,
LFILLT,9,10,R5, ,
KDELE,17
KDELE,16
KDELE,8
KDELE,9
KDELE,10
ESIZE,35/9,0,
AMESH,1
!*
CM,_NODECM,NODE
CM,_ELEMCM,ELEM
CM,_KPCM,KP
CM,_LINECM,LINE
CM,_AREACM,AREA
CM,_VOLUCM,VOLU
/GSAV,cwz,gsav,,temp
MP,MU,1,0
MAT,1
R,3
REAL,3
ET,2,169
ET,3,172
KEYOPT,3,9,0
KEYOPT,3,10,2
R,3,
RMORE,
RMORE,,0
RMORE,0
! Generate the target surface
LSEL,S,,,13
LSEL,A,,,14
LSEL,A,,,15
LSEL,A,,,16
LSEL,A,,,17
LSEL,A,,,18
LSEL,A,,,19
CM,_TARGET,LINE
TYPE,2
LATT,-1,3,2,-1
TYPE,2
LMESH,ALL
! Create a pilot node
KSEL,S,,,14
KATT,-1,3,2,-1
KMESH,14
! Generate the contact surface
LSEL,S,,,2
LSEL,A,,,3
CM,_CONTACT,LINE
TYPE,3
NSLL,S,1
ESLN,S,0
ESURF
*SET,_REALID,3
ALLSEL
ESEL,ALL
ESEL,S,TYPE,,2
ESEL,A,TYPE,,3
ESEL,R,REAL,,3
LSEL,S,REAL,,3
/PSYMB,ESYS,1
/PNUM,TYPE,1
/NUM,1
EPLOT
! Reverse target normals
FLST,5,5,4,ORDE,4
FITEM,5,13
FITEM,5,-15
FITEM,5,17
FITEM,5,-18
CM,_Y,LINE
LSEL, , , ,P51X
CM,_YEL,ELEM
CM,_YND,NODE
NSLL,S,1
ESLN,S,1
ESEL,R,REAL,,_REALID
ESURF,,REVERSE
CMSEL,S,_Y
CMSEL,S,_YEL
CMSEL,S,_YND
CMDELE,_Y
CMDELE,_YEL
CMDELE,_YND
/REPLOT
!*
ESEL,ALL
ESEL,S,TYPE,,2
ESEL,A,TYPE,,3
ESEL,R,REAL,,3
LSEL,S,REAL,,3
/PSYMB,ESYS,1
/PNUM,TYPE,1
/NUM,1
EPLOT
ESEL,ALL
ESEL,S,TYPE,,2
ESEL,A,TYPE,,3
ESEL,R,REAL,,3
LSEL,S,REAL,,3
CMSEL,A,_NODECM
CMDEL,_NODECM
CMSEL,A,_ELEMCM
CMDEL,_ELEMCM
CMSEL,S,_KPCM
CMDEL,_KPCM
CMSEL,S,_LINECM
CMDEL,_LINECM
CMSEL,S,_AREACM
CMDEL,_AREACM
CMSEL,S,_VOLUCM
CMDEL,_VOLUCM
/GRES,cwz,gsav
CMDEL,_TARGET
CMDEL,_CONTACT
)/GOP ! Resume printing after UNDO process
!!!!!!!!!!!!!!!!!!!!!!!!
!*
CM,_NODECM,NODE
CM,_ELEMCM,ELEM
CM,_KPCM,KP
CM,_LINECM,LINE
CM,_AREACM,AREA
CM,_VOLUCM,VOLU
/GSAV,cwz,gsav,,temp
MP,MU,1,0
MAT,1
R,4
REAL,4
ET,4,169
ET,5,172
KEYOPT,5,9,0
KEYOPT,5,10,2
R,4,
RMOR
E,
RMORE,,0
RMORE,0
! Generate the target surf
ace
LSEL,S,,,5
LSEL,A,,,6
LSEL,A,,,7
LSEL,A,,,8
LSEL,A,,,9
LSEL,A,,,10
LSEL,A,,,11
LSEL,A,,,12
LSEL,A,,,20
LSEL,A,,,21
CM,_TARGET,LINE
TYPE,4
LATT,-1,4,4,-1
TYPE,4
LMESH,ALL
! Create a pilot node
KSEL,S,,,13
KATT,-1,4,4,-1
KMESH,13
! Generate the contact surface
LSEL,S,,,1
LSEL,A,,,2
CM,_CONTACT,LINE
TYPE,5
NSLL,S,1
ESLN,S,0
ESURF
*SET,_REALID,4
ALLSEL
ESEL,ALL
ESEL,S,TYPE,,4
ESEL,A,TYPE,,5
ESEL,R,REAL,,4
LSEL,S,REAL,,4
/PSYMB,ESYS,1
/PNUM,TYPE,1
/NUM,1
EPLOT
! Reverse target normals
FLST,5,10,4,ORDE,4
FITEM,5,5
FITEM,5,-12
FITEM,5,20
FITEM,5,-21
CM,_Y,LINE
LSEL, , , ,P51X
CM,_YEL,ELEM
CM,_YND,NODE
NSLL,S,1
ESLN,S,1
ESEL,R,REAL,,_REALID
ESURF,,REVERSE
CMSEL,S,_Y
CMSEL,S,_YEL
CMSEL,S,_YND
CMDELE,_Y
CMDELE,_YEL
CMDELE,_YND
/REPLOT
!*
ESEL,ALL
ESEL,S,TYPE,,4
ESEL,A,TYPE,,5
ESEL,R,REAL,,4
LSEL,S,REAL,,4
/PSYMB,ESYS,1
/PNUM,TYPE,1
/NUM,1
EPLOT
ESEL,ALL
ESEL,S,TYPE,,4
ESEL,A,TYPE,,5
ESEL,R,REAL,,4
LSEL,S,REAL,,4
CMSEL,A,_NODECM
CMDEL,_NODECM
CMSEL,A,_ELEMCM
CMDEL,_ELEMCM
CMSEL,S,_KPCM
CMDEL,_KPCM
CMSEL,S,_LINECM
CMDEL,_LINECM
CMSEL,S,_AREACM
CMDEL,_AREACM
CMSEL,S,_VOLUCM
CMDEL,_VOLUCM
/GRES,cwz,gsav
CMDEL,_TARGET
CMDEL,_CONTACT
/SOL
ANTYPE,0 !激活静力学求解
NLGEOM,1 !激活大变形
!定义边界条件
N1=NODE(L+R1+L1+R2+L2+L4,H1-H5-R5,0) !获取指定位置的节点号
D,N1, , , , , ,ALL, , , , , 约束节点N1所有方向的约束
DL,4, ,UX, !约束线4的X方向位移
!定义载荷
N2=NODE(L+R1+L1+R2+L2,H,0) !获取指定位置的节点号
D,N2, ,-138, , , ,UY, , , , , !施加节点N2的Y方向位移为-138
!定义载荷步
OUTRES,ALL,ALL, !输出所有子步
TIME,1 !定义求解结束时间为1
AUTOTS,1 !激活自动时间步
NSUBST,20,2000,10 !定义求解子步数
KBC,0 !设置载荷为斜坡载荷
RESCONTRL,DEFINE,ALL,ALL,-1 !设置重启动
SOLVE!开始求解
/SOL
!第一次重分网格
REZONE,MANUAL,1,26 !指定重分网格的子步为26
REMESH,START
!创建重分网格的面
/UI,COLL,0
CMDEL,REZONE_CM
AREMESH,0,30,
/UI,COLL,1
ESIZE,2.5,0, !设置总体尺寸为2.5
MSHAPE,0,2D !使用二维四边形网格
MSHKEY,0 !使用自由网格划分
AMESH,2 !划分面2
REMESH,FINISH
AREMESHCN
MAPSOLVE,50, !开始网格映射求解
FINISH
/SOLUTION
ANTYPE,,RESTART !激活重启动
SOLVE !开始求解
FINISH
!第二次重分网格
REZONE,MANUAL,1,48 !指定重分网格的子步为26
REMESH,START
!创建重分网格的面
/UI,COLL,0
CMDEL,REZONE_CM
AREMESH,0,30,
/UI,COLL,1
ESIZE,2.2,0, !设置总体尺寸为2.2
MSHAPE,0,2D !使用二维四边形网格
MSHKEY,0 !使用自由网格划分
AMESH,2 !划分面2
REMES
H,FINISH
AREMESHCN
MAPSOLVE,50, !开始网格映射求解
FINISH
/SOLUTION
ANTYPE,,
RESTART !激活重启动
SOLVE !开始求解
FINISH
技术文档
热门文章
155-2731-8020