跪求主轴模态分析出现这样的问题，如何解决
finish/clear
!相关参数建立如下所示
pi=2*asin(1)
a=0.14480
b=0.100
c=0.120
d=0.59820!d=0.604
*DIM,y,array,12
*DIM,z,array,12
*DIM,yy,array,12
*DIM,zz,array,12
*DO,i,1,12 !循环命令
y(i)=b*sin(i*pi/6)
z(i)=b*cos(i*pi/6)
yy(i)=c*sin(i*pi/6)
zz(i)=c*cos(i*pi/6)
*ENDDO
r1=0.045
l1=0.034
r2=0.115
l2=0.109
r3=0.100
l3=0.634
r4=0.075
l4=0.734
r5=0.065
l5=0.862
r6=0.045
l6=0.905
/prep7
!创建关键点
k,1,0,0
k,2,0,r1
k,3,l1,r1
k,4,l1,r2
k,5,l2,r2
k,6,l2,r3
k,7,l3,r3
k,8,l3,r4
k,9,l4,r4
k,10,l4,r5
k,11,l5,r5
k,12,l5,r6
k,13,l6,r6
k,14,l6,0
k,15,l1,0
k,16,l2,0
k,17,l3,0
k,18,l4,0
k,19,l5,0
!创建直线
l,1,2
l,2,3
l,3,4
l,4,5
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,13,14
l,14,19
l,15,3
l,16,6
l,17,8
l,18,10
l,19,12
l,19,18 !20
l,18,17 !21
l,17,16!22
l,16,15 !23
l,15,1 !24
l,4,15 !25
l,5,16
l,7,17
l,9,18
l,11,19 !29
!关键线创建面
al,1,2,15,24
al,4,25,26,23
al,6,16,27,22
al,8,17,28,21
al,10,18,29,20
al,12,13,19,14
!a,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
!定义材料属性
mp, ex,1,1.45e11
mp,dens,1,7.8e3
mp,prxy,1,0.3
!定义单元类型
et,1,plane42
et,2,solid45
et,3,14
!keyopt,3,2,2!y向
!keyopt,4,2,3 !z向
!keyopt,5,2,1 !x向
!弹簧刚度参数
r,1,3e8!定义K,uy!r,4,8e7!定义K,uz
r,2,2.5e7!定义K,ux
mat,1
type,1
!面1的网格划分
FLST,5,2,4,ORDE,2
FITEM,5,1
FITEM,5,15
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.005, , , , , , ,1
FLST,5,2,4,ORDE,2
FITEM,5,2
FITEM,5,24
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.012, , , , , , ,1
MSHAPE,0,2D
MSHKEY,0
CM,_Y,AREA
ASEL, , , , 1
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!面2的网格划分
FLST,5,2,4,ORDE,2
FITEM,5,25
FITEM,5,26
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.005, , , , , , ,1
FLST,5,2,4,ORDE,2
FITEM,5,4
FITEM,5,23
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.012, , , , , , ,1
MSHAPE,0,2D
MSHKEY,0
CM,_Y,AREA
ASEL, , , , 2
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!面3的网格划分
FLST,5,2,4,ORDE,2
FITEM,5,16
FITEM,5,27
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.005, , , , , , ,1
FLST,5,2,4,ORDE,2
FITEM,5,6
FITEM,5,22
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.012, , , , , , ,1
MSHAPE,0,2D
MSHKEY,0
CM,_Y,AREA
ASEL, , , , 3
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!面4的网格划分
FLST,5,2,4,ORDE,2
FITEM,5,17
FITEM,5,28
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.005, , , , , , ,1
FLST,5,2,4,ORDE,2
FITEM,5,8
FITEM,5,21
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.012, , , , , , ,1
MSHAPE,0,2D
MSHKEY,0
CM,_Y,AREA
ASEL, , , , 4
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!面5的网格划分
FLST,5,2,4,ORDE,2
FITEM,5,18
FITEM,5,29
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.005, , , , , , ,1
FLST,5,2,4,ORDE,2
FITEM,5,10
FITEM,5,20
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.012, , , , , , ,1
MSHAPE,0,2D
MSHKEY,0
CM,_Y,AREA
ASEL, , , , 5
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!面6的网格划分
FLST,5,2,4,ORDE,2
FITEM,5,19
FITEM,5,13
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.005, , , , , , ,1
FLST,5,2,4,ORDE,2
FITEM,5,12
FITEM,5,14
CM,_Y,LINE
LSEL, , , ,P51X
CM,_Y1,LINE
CMSEL,,_Y
LESIZE,_Y1,0.012, , , , , , ,1
MSHAPE,0,2D
MSHKEY,0
CM,_Y,AREA
ASEL, , , , 6
CM,_Y1,AREA
CHKMSH,'AREA'
CMSEL,S,_Y
AMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
!aglue,all
!nummrg,all
!面旋转为体
TYPE, 2
EXTOPT,ESIZE,6,0,
MAT,1
VROTAT,1, , , , , ,14,0,360, ,
VROTAT,2, , , , , ,14,0,360, ,
VROTAT,3, , , , , ,14,0,360, ,
VROTAT,4, , , , , ,14,0,360, ,
VROTAT,5, , , , , ,14,0,360, ,
VROTAT,6, , , , , ,14,0,360, ,
EPLOT
nummrg,all
!vglue,all
!创建新的节点坐标
*DO,i,1,12 !循环命令
n,60000+i,a,yy(i),zz(i)
n,60000+12+i,a+0.1,y(i),z(i)
n,60000+24+i,d,yy(i),zz(i)
n,60000+36+i,d-0.1,y(i),z(i)
*ENDDO
!通过坐标得到与其重合结点编号
*DIM,node_domn,array,24
*DIM,node_up,array,24
*DIM,node_md,array,24
*DO,i,1,12 !循环命令
*set,node_domn(i),node(a,y(i),z(i))
*set,node_domn(i+12),node(d,y(i),z(i))
*set,node_up(i),node(a,yy(i),zz(i))
*set,node_up(i+12),node(d,yy(i),zz(i))
*set,node_md(i),node(a+0.1,y(i),z(i))
*set,node_md(i+12),node(d-0.1,y(i),z(i))
*ENDDO
!建立弹簧单元
type,3
*DO,i,1,12 !循环命令
real,1
e,node_domn(i),node_up(i)
e,node_domn(i+12),node_up(i+12)
*ENDDO
type,3
*DO,i,1,12 !循环命令
real,2
e,node_domn(i),node_md(i)
e,node_domn(i+12),node_md(i+12)
*ENDDO
eplot
save
!求解过程
/solu
ANTYPE,2
*do,i,1,24
d,node_up(i),all,0
d,node_md(i),all,0
*enddo
MODOPT,LANB,12,0,0, ,OFF
EQSLV,SPARSE
MXPAND,12, , ,0
LUMPM,0
PSTRES,0
solve
save
固有频率1 0.46100E-03 1 1 1
2135.07 1 2 2
3264.15 1 3 3
4324.79 1 4 4
5565.42 1 5 5
6641.83 1 6 6
7753.04 1 7 7
81019.8 1 8 8
91568.0 1 9 9
101842.0 1 10 10
112040.3 1 11 11
122579.6 1 12 12
从求解结果可看出，此主轴的固有频率没有出现重根，应该有重根呀？
采用自底向上建模，建立主轴截面，划分映射网格，旋转，加约束求解，为什么求解的不对呀？是不是旋转需要特殊处理呀？ 求高手赐教!! 回复 2 # 1353963615 的帖子
好悲剧呀，竟然没有人帮下忙解决下呀！呼唤高手呀 {:{19}:} 约束应该有问题，没有出现对称模态，约束是否对称？第一阶频率等于0了····· 本帖最后由 niej2008 于 2012-8-29 15:45 编辑
我在导入LZ的命令时会报警，中断运行。。。是我的版本原因吗，我用的10.0
回复 5 # yyxt007 的帖子
我采用的是径向弹簧，和轴向弹簧约束，径向对称。第一阶刚体模态扭转为零，乐意接受，第二阶，轴向振动，没问题，关键是三阶和四阶不对称，五阶和六阶不对称。我自认为径向约束是对称的，谢谢啊，我在检查下（将弹簧个数设置少些试试）。 回复 6 # niej2008 的帖子
可能是网格过密，内存不足吧 回复 6 # niej2008 的帖子
我用的是11.0
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