蜂窝夹层板的模态分析,上下蒙皮和中间蜂窝芯的材料不同,apdl如下,不管如何修改边条都出现奇怪的频率(0.几或者数十万)或振型(不是板型整体横向摆动,而是会出现个别蜂窝上下跳窜),请高人指点迷津,我快废了
/CLEAR
/COM, Structural
/FILNAME,Modal,on
/TITLE, Modal analysis of a honeycomb sandwich panel.
/UNIT,SI
t=5.e-5 !* 蜂窝芯厚度t=0.05mm,边长L,芯高H,蒙皮厚度b
L=5.e-4
H=1.e-3
b=1.5e-4
/PREP7
et,1,shell91
et,2,shell91
r,1
rmodif,1,1,1 !* facesheet划分为1层
rmodif,1,13,1,0,b
r,2
rmodif,2,1,1 !* core划分为1层
rmodif,2,13,2,0,t
mp,ex,1,2.07e11 !* 镍基合金物性参数
mp,prxy,1,0.278
mp,dens,1,8414
mp,ex,2,4.95e9 !* 某合金物性参数
mp,prxy,2,0.278
mp,dens,2,190.71
k,1,0,L/2.
k,2,0,1.5*L
k,3,sqrt(3.)*L/2.,2.*L
k,4,sqrt(3.)*L,1.5*L
k,5,sqrt(3.)*L,L/2.
k,6,sqrt(3.)*L/2.
kgen,2,1,6,,,,H
*DO,i,1,5
l,i,i+1
*ENDDO
l,6,1
*DO,j,7,11
l,j,j+1
*ENDDO
l,12,7
*DO,k,1,6
l,k,k+6
*ENDDO
l,3,6
l,9,12
a,1,2,3,6
a,3,4,5,6
a,7,8,9,12
a,9,10,11,12
*DO,i,1,5
a,i,i+1,i+7,i+6
*ENDDO
a,6,1,7,12
/REPLOT
*DO,i,1,4
asel,all
agen,2,all,,,2**(i-1)*sqrt(3)*L
*ENDDO
*DO,j,1,2
asel,all
agen,2,all,,,2**(j-1)*sqrt(3)*L/2,2**(j-1)*1.5*L
*ENDDO
!* 手动裁剪所需胞元使得板型为长方形
/RGB,index,100,100,100,0
/RGB,index,80,80,80,13
/RGB,index,60,60,60,14
/RGB,index,0,0,0,15
allsel
lsel,s,loc,z,0 !* facesheet网格布点
lsel,a,loc,z,H
lplot
lesize,all,,,2
asel,s,loc,z,0 !* 映射分网facesheet
asel,a,loc,z,H
type,1
real,1
mat,1
mshkey,1
amesh,all
eplot
/IMAGE,save,mesh_facesheet,bmp
allsel
lsel,u,loc,z,0 !* core网格布点
lsel,u,loc,z,H
lplot
lesize,all,,,4
asel,u,loc,z,0
asel,u,loc,z,H
type,2 !* 映射分网core
real,2
mat,2
mshkey,1
amesh,all
allsel
eplot
/IMAGE,save,mesh_all,bmp
finish
/SOLU
antype,modal
modopt,lanb,10,0,10000,,off !* 提取前10阶模态,并以质量矩阵正则化模态
eqslv,spar
mxpand,10, , ,1
lumpm,0
pstres,0
!* 施加边条,一般为左侧简支或对称边条
!* lsel,s,line,,1,6
!* dl,all,,all,0
allsel
solve
finish
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