做一个悬臂梁的振动仿真，为什么模态分析振型是错误的？

wang11120277

程序是这样的，谁能帮看一下吗？

FINISH  
/CLEAR,NOSTART  
/title,piezoelectric_vibration_analysis
/prep7
a1=0.010
a2=a1-0.002
a=0.010
b=0.003
c=0.00015
VEL=2
M=0.0002

et,1,solid5,2
MP,ex,1,9.8e10           !黄铜
MP,nuxy,1,.32
MP,dens,1,7500

et,2,solid5,3
mp,dens,2,7750            !PZT材料密度
mp,perx,2,916              !介电常数
mp,pery,2,916
mp,perz,2,830
tb,piez,2,,,0                 !压电常数           
tbdata,3,-5.4
tbdata,6,-5.4
tbdata,9,15.8
tbdata,14,12.3
tbdata,16,12.3
tb,anel,2,,,1,,           !弹性常数                       
tbdata,1,16.4e-12,-5.74e-12,-7.22e-12,0,0,0
tbdata,7,16.4e-12,0,0,0,0
tbdata,12,18.8e-12,0,0,0
tbdata,16,44.3e-12,0,0  
tbdata,19,47.5e-12,0   
tbdata,21,47.5e-12

ET,3,MASS21,0,0,2          !质量
R,1,M                      !锡块质量

!!!!!!!!!!!!!!!!!!!!     建模
/view,,1,1,1
/vup,,z
/DSCALE,,1
block,0,a,-b/2,b/2,0,c
block,0,a,-b/2,b/2,c,2*c
NUMMRG,ALL
NUMCMP,ALL
WPAVE,
ALLSEL,ALL
VGLUE,ALL
TYPE,1
MAT,1
LSEL,S,,,2,4,2
LSEL,A,,,5,7,2
LSEL,A,,,13,15,2
LESIZE,ALL,,,60
LSEL,S,,,1,3,2
LSEL,A,,,6,8,2
LSEL,A,,,14,16,2
LESIZE,ALL,,,30
LSEL,S,,,9,12,1
LSEL,A,,,17,20,1
LESIZE,ALL,,,1
VSEL,S,,,1
MSHAPE,0,3D
MSHKEY,1
VMESH,ALL

TYPE,2
MAT,2
VSEL,S,,,2
VMESH,ALL
ALLSEL,ALL

ASEL,S,,,5,10,5
DA,ALL,UX,0,1
DA,ALL,UY,0,1
DA,ALL,UZ,0,1

TYPE,3                   !!!质量载荷
NSEL,S,LOC,Y,-0.00007+0,0.00007+0
NSEL,R,LOC,X,-0.00007+0,0.00007+0
NSEL,R,LOC,Z,-0.00007+C,0.00007+C
*get,nodenum,node,0,num,min
E,nodenum
ALLSEL,ALL

!ACEL,,,-9.8
ALLSEL,ALL

NSEL,S,LOC,Z,C*2               !!!耦合载荷               
CP,1,VOLT,ALL
ALLSEL,ALL
NSEL,S,LOC,Z,C
D,ALL,VOLT,0,
CP,2,VOLT,ALL
ALLSEL,ALL
FINISH

/SOLU
ANTYPE,MODAL
MODOPT,LANB,5,
ALLSEL,ALL
SOLVE
FINISH

/POST1  
SET,LIST,999算出来的阵型如下，明显是错误的，究竟是什么问题呢？

亲爱的伽利略

初学者，我也不会。