动力学模态问题

zglecsi

我建立了一个开裂梁（裂缝宽度为0.4mm）的有限元模型，对其进行模态分析，结果是算出来了，但是与无损伤梁比较，各阶频率都稍大，按道理，损伤梁的频率应该比无损梁的频率小才对啊？不知道问题出在哪里，还请各位高手指教！

希望哪位高手能帮忙运行一下，求解很快，不到30秒！

/prep7
!定义单元类型
et,1,solid65
et,2,plane42

!定义实常数
r,1,2,0.02792               !受拉钢筋直径16mm,面积201.1e-6mm
                             
!定义材料属性
mp,ex,1,2.55e10      !混凝土 C20
mp,prxy,1,0
mp,dens,1,2.5e3
tb,conc,1,1,9
tbdata,,0.4,1,1.10e6,-1


mp,ex,2,2e11        !受拉钢筋
mp,prxy,2,0.3
mp,dens,2,7.83e3    !考虑钢筋质量


/pnum,node,1
/pnum,elem,1

!产生所有的节点

n,1
n,81,1.2
fill,1,81
ngen,11,81,1,81,1,,0.015

type,2
k,1,
k,2,0,0.15
k,3,1.2,0.15
k,4,1.2
k,5,0.615
k,6,0.615,0.015
k,7,0.6,0.015
k,8,0.585,0.015
k,9,0.585
                              !建立裂缝区结点,裂缝宽度为0.4mm
k,10,0.5998
k,11,0.6002
k,12,0.5948,0.005  
k,13,0.5998,0.005
k,14,0.6002,0.005
k,15,0.6052,0.005
k,16,0.5948,0.010  
k,17,0.5998,0.010
k,18,0.6002,0.010
k,19,0.6052,0.010


a,1,2,3,4,5,6,7,8,9

lsel,s,length,,0.15
lesize,all,0.015
lsel,all
lsel,s,length,,1.2
lesize,all,0.015
lsel,all
lsel,s,length,,0.585
lesize,all,0.015
lsel,all
lsel,s,length,,0.015
lesize,all,0.015
lsel,all
amesh,all


type,2
a,7,8,16,17
a,7,6,19,18
a,8,9,12,16
a,6,5,15,19
a,16,17,13,12
a,18,19,15,14
a,9,10,13,12
a,5,11,14,15

lsel,s,line,,5
lsel,a,line,,6
lsel,a,line,,7
lsel,a,line,,8
lsel,a,line,,10
lsel,a,line,,11
lsel,a,line,,12
lsel,a,line,,13
lsel,a,line,,14
lsel,a,line,,15
lsel,a,line,,16
lsel,a,line,,17
lsel,a,line,,18
lsel,a,line,,19
lsel,a,line,,20
lsel,a,line,,21
lsel,a,line,,22
lsel,a,line,,23
lsel,a,line,,24
lsel,a,line,,25
lsel,a,line,,26
lsel,a,line,,27


lesize,all,,,1
amesh,all



allsel,all,all
type,1
real,1
mat,1
extopt,esize,4
extopt,aclear,1
vext,all,,,,,-0.12
allsel，all
nummrg,all
numcmp,all

/sol
antype,modal
allsel,all
modopt,subsp,10
nsel,s,loc,y,0
nsel,r,loc,x,0.06
d,all,uy
d,all,ux


nsel,s,loc,y,0
nsel,r,loc,x,1.14
d,all,uy

ALLSEL,ALL
MXPAND,10
SOLVE
FINISH

zglecsi

等待大侠指教！