概述

    在结构设计中,模态分析是结构动力学分析最重要的内容之一,也是考察结构抗风、抗震以及其他动载作用下结构稳定性必不可少的步骤。市面上,ANSYS、迈达斯、SAP等商业有限元软件可以完成结构的模态分析,但对设计者来说自编程序来实现依然很有意义。自编程序意义如下:1. 可以和商业软件互相作校核;2. 能从原理上更深入理解,避免看到一个计算结果没有概念,不知道对错。
    模态分析的核心是求出结构的总刚度矩阵和总质量矩阵,并作特征值分析,求出结构的频率和振型。前处理包括数据的准备,后处理为画振型图,方便查看。

原理

    模态分析的原理和一般有限元分析类型,即结构离散、计算单刚、生成总刚、支座处理,质量矩阵的生成和刚度矩阵类似。刚度矩阵和质量矩阵出来再作特征值分析,得到频率和振型。
    以梁式桥为例,单元刚度矩阵采用铁木辛柯单元:

质量矩阵:

如果存在集中质量块的,集中质量块的质量矩阵:


单元之间组合时,采用同一个整体坐标系,单元局部坐标系转换到整体坐标系时,坐标转换矩阵为:

其中


单刚和单元质量矩阵坐标转换公式如下:
    
集中质量块不涉及坐标转换。

单刚和单元质量矩阵按节点分块,并累加到总刚对应位置中,如下图:

支座处理采用划零置一法:如果位移矩阵中第j行被约束,位移为Cj,则总刚总第j行和第j列都赋值0,第j行第j列元素赋值为1,如下图。

如果单元与单元之间存在刚臂,则设置一个虚拟的刚臂单元,刚臂单元质量为零,弹模和剪模放大10^10倍。
结构自由振动,忽略阻尼时,动力学方程如下:



其中,⍵j为第j阶频率,Xj为j阶振型。上面的方程特征值求解,则有:

生成总刚流程图如下,总质量矩阵生成流程也类似:

代码实现

    首先编写生成总刚和总质量矩阵的函数,保存为Timoshenko.m

  function [Kzonggang,me,ke,ke1,Mzongzhiliang,Tzhuanhuan]=Timoshenko(danyuan,jiedian,jiemian,cailiao,gangbi,jizhongkuai)%%%%Timoshenko  铁木辛柯单元算总刚度矩阵和总质量矩阵% dangyuan  单元; jiedian  节点;jiemian  截面;cailiao  材料;gangbi  刚臂;jizhongkuai  集中质量块% Kzonggang  总刚度矩阵;Mzongzhiliang  总质量矩阵;Tzhuanhuan  转换矩阵;me  单元质量矩阵集;ke  单元刚度矩阵集;ke1  坐标转换后的单元刚度矩阵集c1=size(danyuan);
c2=size(jiedian);
c3=size(gangbi);
c4=size(jizhongkuai);
lenth=zeros(c1(1),1);%%%%%%%%%%%%%%%%%%%%%%%%%%%%%杆件长度
aaa=zeros(c1(1),1);
Ay=zeros(c1(1),1);
Az=zeros(c1(1),1);
Iz=zeros(c1(1),1);
Iy=zeros(c1(1),1);
J=zeros(c1(1),1);
ry=zeros(c1(1),1);
rz=zeros(c1(1),1);
e=zeros(c1(1),1);
G=zeros(c1(1),1);
By=zeros(c1(1),1);
Bz=zeros(c1(1),1);
rrou=zeros(c1(1),1);%密度
ke=zeros(12,12,c1(1));
ke1=zeros(12,12,c1(1));
me=zeros(12,12,c1(1));
Mzongzhiliang=zeros(6*c2(1));
Kzonggang=zeros(6*c2(1));
kee=zeros(12,12);
Tzhuanhuan=zeros(12,12,c1(1));%转换矩阵
fai=zeros(3,3,c1(1));%%%%%%%%%%%%%%%%%%%%%%%%%%%%单元转换矩阵
ll=zeros(3);
lll=zeros(12);for i=1:c1(1);a=danyuan(i,1);b=danyuan(i,2);a0=jiedian(a,4);b0=jiedian(b,4);a1=(jiedian(b,1)-jiedian(a,1));a2=(jiedian(b,2)-jiedian(a,2));a3=(jiedian(b,3)-jiedian(a,3));lenth(i)=sqrt(a1*a1+a2*a2+a3*a3);%杆件长度%%%%%%fai(1,1,i)=a1/lenth(i);fai(1,2,i)=a2/lenth(i);fai(1,3,i)=a3/lenth(i);alfa=fai(1,1,i);beita=danyuan(i,4);        x0=[1 0 0];y0=[0 1 0];z0=[0 0 1];x1=[fai(1,1,i) fai(1,2,i) fai(1,3,i)];if(alfa~=1)T0=cross(x0,x1);T=T0/norm(T0,2);dy1=cross(T,y0);if(norm(dy1)==0)y1=y0;elsedy1=dy1/norm(dy1);dy2=cross(dy1,T);dy2=dy2/norm(dy2);if(T(1)==dy2(1))s1=y0(2:3);s2=[T(2:3);dy2(2:3)];elseif(T(2)==dy2(2))s1=y0(1:3:2);s2=[T(1:3:2);dy2(1:3:2)];elses1=y0(2:3);s2=[T(2:3);dy2(2:3)];enday=s1/s2;dy3=cos(alfa)*dy2+sin(alfa)*dy1;y1=ay*[T;dy3];endz1=cross(x1,y1);elsey1=y0;z1=z0;endfai(2,:,i)=[cos(beita) sin(beita)]*[y1;z1];fai(3,:,i)=[-sin(beita) cos(beita)]*[y1;z1];%转换矩阵%%%%%%%Ay(i)=(jiemian(a0,2)+jiemian(b0,2))/2;Az(i)=(jiemian(a0,3)+jiemian(b0,3))/2;aaa(i)=(jiemian(a0,1)+jiemian(b0,1))/2;Iz(i)=(jiemian(a0,6)+jiemian(b0,6))/2;Iy(i)=(jiemian(a0,5)+jiemian(b0,5))/2;J(i)=(jiemian(a0,4)+jiemian(b0,4))/2;ry(i)=sqrt(Iy(i)/aaa(i));rz(i)=sqrt(Iz(i)/aaa(i));%ry(i)=0;%rz(i)=0;a0=danyuan(i,3);e(i)=cailiao(a0,1);%弹模G(i)=cailiao(a0,2);%剪模rrou(i)=cailiao(a0,3);ll(:,:)=fai(:,:,i);
endif(c3(2)>1)          %刚性单元刚度异常大,密度为0for i=1:c3(2)-1a0=gangbi(i+1);rrou(a0)=0;e(a0)=10000000000000000000;G(a0)=10000000000000000000;end
endfor i=1:c1(1);By(i)=12*e(i)*Iz(i)/(G(i)*Ay(i)*lenth(i)*lenth(i));Bz(i)=12*e(i)*Iy(i)/(G(i)*Az(i)*lenth(i)*lenth(i));
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%求单元长度及转换矩阵for j=1:c1(1)t=zeros(12);ke(1,1,j)=e(j)*aaa(j)/lenth(j);ke(7,1,j)=-e(j)*aaa(j)/lenth(j);ke(2,2,j)=G(j)*Ay(j)/lenth(j);ke(6,2,j)=0.5*G(j)*Ay(j);ke(8,2,j)=-G(j)*Ay(j)/lenth(j);ke(12,2,j)=0.5*G(j)*Ay(j);ke(3,3,j)=G(j)*Az(j)/lenth(j);ke(5,3,j)=-0.5*G(j)*Az(j);ke(9,3,j)=-G(j)*Az(j)/lenth(j);ke(11,3,j)=-0.5*G(j)*Az(j);ke(4,4,j)=G(j)*J(j)/lenth(j);ke(10,4,j)=-G(j)*J(j)/lenth(j);ke(5,5,j)=0.25*G(j)*Az(j)*lenth(j)+e(j)*Iy(j)/lenth(j);ke(9,5,j)=0.5*G(j)*Az(j);ke(11,5,j)=0.25*G(j)*Az(j)*lenth(j)-e(j)*Iy(j)/lenth(j);ke(6,6,j)=0.25*G(j)*Ay(j)*lenth(j)+e(j)*Iz(j)/lenth(j);ke(8,6,j)=-0.5*G(j)*Ay(j);ke(12,6,j)=0.25*G(j)*Ay(j)*lenth(j)-e(j)*Iz(j)/lenth(j);ke(7,7,j)=e(j)*aaa(j)/lenth(j);ke(8,8,j)=G(j)*Ay(j)/lenth(j);ke(12,8,j)=-0.5*G(j)*Ay(j);ke(9,9,j)=G(j)*Az(j)/lenth(j);ke(11,9,j)=0.5*G(j)*Az(j);ke(10,10,j)=G(j)*J(j)/lenth(j);ke(11,11,j)=0.25*G(j)*Az(j)*lenth(j)+e(j)*Iy(j)/lenth(j);ke(12,12,j)=0.25*G(j)*Ay(j)*lenth(j)+e(j)*Iz(j)/lenth(j);%%%%%%%%%%%%%%%%%%%%%%%%%%%%%me(1,1,j)=2*aaa(j);me(7,1,j)=aaa(j);me(2,2,j)=2*aaa(j);me(8,2,j)=aaa(j);me(3,3,j)=2*aaa(j);me(9,3,j)=aaa(j);me(4,4,j)=2*J(j);me(10,4,j)=J(j);me(5,5,j)=2/35*aaa(j)*lenth(j);me(11,5,j)=-3/70*aaa(j)*lenth(j);me(6,6,j)=2/35*aaa(j)*lenth(j);me(12,6,j)=-3/70*aaa(j)*lenth(j);me(7,7,j)=2*aaa(j);me(8,8,j)=2*aaa(j);me(9,9,j)=2*aaa(j);me(10,10,j)=2*J(j);me(11,11,j)=2/35*aaa(j)*lenth(j);me(12,12,j)=2/35*aaa(j)*lenth(j);for k1=1:11for k2=k1+1:12ke(k1,k2,j)=ke(k2,k1,j);me(k1,k2,j)=me(k2,k1,j);endendme(:,:,j)=(rrou(j)*lenth(j))*me(:,:,j)/6;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%输入局部坐标下单刚及一致质量矩阵for k1=1:3for k2=1:3t(k1,k2)=fai(k1,k2,j);t(k1+3,k2+3)=fai(k1,k2,j);t(k1+6,k2+6)=fai(k1,k2,j);t(k1+9,k2+9)=fai(k1,k2,j);endendTzhuanhuan(:,:,j)=t;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%输入转换矩阵kee(:,:)=ke(:,:,j);kee=t'*kee*t;%%%%%%%%%%%%%%%%%%%%%%%整体坐标下单刚ke1(:,:,j)=kee;lll(:,:)=me(:,:,j);lll=t'*lll*t;a=danyuan(j,1)-1;b=danyuan(j,2)-1;for k1=1:6for k2=1:6Kzonggang(6*a+k1,6*a+k2)= Kzonggang(6*a+k1,6*a+k2)+kee(k1,k2);Kzonggang(6*a+k1,6*b+k2)= Kzonggang(6*a+k1,6*b+k2)+kee(k1,k2+6); Kzonggang(6*b+k1,6*a+k2)= Kzonggang(6*b+k1,6*a+k2)+kee(k1+6,k2); Kzonggang(6*b+k1,6*b+k2)= Kzonggang(6*b+k1,6*b+k2)+kee(k1+6,k2+6);%%%%Mzongzhiliang(6*a+k1,6*a+k2)= Mzongzhiliang(6*a+k1,6*a+k2)+lll(k1,k2);Mzongzhiliang(6*a+k1,6*b+k2)= Mzongzhiliang(6*a+k1,6*b+k2)+lll(k1,k2+6); Mzongzhiliang(6*b+k1,6*a+k2)= Mzongzhiliang(6*b+k1,6*a+k2)+lll(k1+6,k2); Mzongzhiliang(6*b+k1,6*b+k2)= Mzongzhiliang(6*b+k1,6*b+k2)+lll(k1+6,k2+6);endend
end
if(c4(1)>1)for i=1:c4(1)-1a0=jizhongkuai(i+1,1);b0=jizhongkuai(i+1,2);Mzongzhiliang(6*a0-5,6*a0-5)=Mzongzhiliang(6*a0-5,6*a0-5)+b0;Mzongzhiliang(6*a0-4,6*a0-4)=Mzongzhiliang(6*a0-4,6*a0-4)+b0;Mzongzhiliang(6*a0-3,6*a0-3)=Mzongzhiliang(6*a0-3,6*a0-3)+b0;end
end

接下来编写绘图的方法,保存为draw.m

function picture=draw(jiedian,danyuan,tzxlsjzg,index)
warning off;
c1=size(jiedian);
c2=size(danyuan);
Ndy=c2(1);
NN=c1(1);
ss=2/max(abs(tzxlsjzg(:,index)));
%%%%%%%%%%%%%%%%%%%%%%%%%%%%变形前
plot3(jiedian(:,1),jiedian(:,2),jiedian(:,3),'.r')%画节点
hold on
for j=1:Ndya1=danyuan(j,1);a2=danyuan(j,2);Xdx=[jiedian(a1,1);jiedian(a2,1)];Xdy=[jiedian(a1,2);jiedian(a2,2)];Xdz=[jiedian(a1,3);jiedian(a2,3)];plot3(Xdx,Xdy,Xdz,'-r')%画单元hold on
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%变形前%%%%%%%%%%%%%%%%%%%%%%%%%%%%变形后
ZXjiedian=zeros(NN,3);
for j=1:NNZXjiedian(j,1)=jiedian(j,1)+ss*tzxlsjzg(6*j-5,index);ZXjiedian(j,2)=jiedian(j,2)+ss*tzxlsjzg(6*j-4,index);ZXjiedian(j,3)=jiedian(j,3)+ss*tzxlsjzg(6*j-3,index);
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%plot3(ZXjiedian(:,1),ZXjiedian(:,2),ZXjiedian(:,3),'*b');%画节点
hold on
for j=1:Ndya1=danyuan(j,1);a2=danyuan(j,2);Xdx=[ZXjiedian(a1,1);ZXjiedian(a2,1)];Xdy=[ZXjiedian(a1,2);ZXjiedian(a2,2)];Xdz=[ZXjiedian(a1,3);ZXjiedian(a2,3)];plot3(Xdx,Xdy,Xdz,'-b')%画单元hold on
end
axis equal
grid on
hold off
fp=strcat('第',int2str(index),'阶振型图');
title(fp);

接下来编写主程序

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%数据读取
a10='G:\模态分析';
a11='最新数据1.txt';
a1=strcat(a10,'\',a11);
fid1=fopen(a1,'r');
shuju=fscanf(fid1,'%f %f',[9,1]);NN=fscanf(fid1,'%f %f',[1,1]);                                             %节点总数jiedian=fscanf(fid1,'%f %f',[5,NN]);                                       %节点信息
jiedian=jiedian';Nzljd=fscanf(fid1,'%f %f',[1,1]);                                          %主梁节点数Nqiaodun=fscanf(fid1,'%f %f',[1,1]);                                       %桥墩数Ngdjds=fscanf(fid1,'%f %f',[Nqiaodun,1]);                                  %各墩节点数Hgddm=fscanf(fid1,'%f %f',[Nqiaodun,1]);                                   %各墩墩地面处竖坐标 Ndy=fscanf(fid1,'%f %f',[1,1]);                                            %单元数danyuan=fscanf(fid1,'%f %f',[4,Ndy]);                                     %单元信息
danyuan=danyuan';Nldjiedian=fscanf(fid1,'%f %f',[1,1]);                                     %刚臂单元数ldjedangyuan=fscanf(fid1,'%f %f',[Nldjiedian,1]);                          %刚臂单元号
ldjedangyuan=ldjedangyuan';Nzhizuo=fscanf(fid1,'%f %f',[1,1]);                                        %支座数zhizuo=fscanf(fid1,'%f %f',[3,Nzhizuo]);                                   %支座信息
zhizuo=zhizuo';%%%%                                                                       %%%
Njiemian=fscanf(fid1,'%f %f',[1,1]);                                       %截面数jiemian=fscanf(fid1,'%f %f',[24,Njiemian]);                                %截面特性
jiemian=jiemian';sflxs=fscanf(fid1,'%f %f',[12,Njiemian]);                                   %三分力系数
sflxs=sflxs';Ncailiao=fscanf(fid1,'%f %f',[1,1]);                                       %材料数cailiao=fscanf(fid1,'%f %f',[3,Ncailiao]);                                 %材料特性E,G,rou
cailiao=cailiao';                                                 Njzm=fscanf(fid1,'%f %f',[1,1]);                                           %集中质量块数if(Njzm>0)jzm=fscanf(fid1,'%f %f',[2,Njzm]);                                      %集中块节点号及质量jzm=jzm';
end
fclose(fid1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%总刚及质量矩阵
Nldjiedian=ldjedangyuan(1,1);
jiedian1=jiedian(:,1:4);
for i=1:NNi1=jiedian(i,4);h1=jiemian(i1,9);if(jiedian(i,5)==0)jiedian1(i,3)=jiedian(i,3)-h1;end
end
[KK,me,Kke,Kke1,M,tt]=Timoshenko(danyuan,jiedian1,jiemian,cailiao,ldjedangyuan,jzm);
KK1=KK;
KK2=KK;
M1=M;
M2=M;
for i=1:Nzhizuok=6*(zhizuo(i,1)-1)+zhizuo(i,2);KK1(k,:)=zeros(1,6*NN);KK2(k,:)=zeros(1,6*NN);M1(k,:)=zeros(1,6*NN);M2(k,:)=zeros(1,6*NN);KK1(:,k)=zeros(6*NN,1);KK2(:,k)=zeros(6*NN,1);M1(:,k)=zeros(6*NN,1);M2(:,k)=zeros(6*NN,1);KK1(k,k)=-1;KK2(k,k)=1;M1(k,k)=0.00001;M2(k,k)=1;
end
[tzxlsjzg,tzzsjzg]=eig(KK1,M1);%%%%%%%特征向量-振型,特征值-频率平方
omiga=zeros(6*NN,1);
for i=1:6*NNomiga(i)=tzzsjzg(i,i);
end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%对振型和频率排序
omiga11=omiga;
omiga21=omiga;
t=max(omiga21);
s=zeros(6*NN,1);
for i=1:6*NNa=1;for j=1:6*NNif(omiga11(a)>omiga11(j))a=j;endends(i)=a;omiga11(a)=t+1;
end
tzxlsjzg2=tzxlsjzg;
for i=1:6*NNa=s(i);omiga(i)=omiga21(a);tzxlsjzg(:,i)=tzxlsjzg2(:,a);
end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%支座处奇异值处理
omiga0=omiga;
omiga=omiga(Nzhizuo+1:Nzhizuo+10);
omiga=sqrt(omiga);
for i=1:Nzhizuok=6*(zhizuo(i,1)-1)+zhizuo(i,2);tzxlsjzg(k,:)=zeros(1,6*NN);
end
tzxlsjzg1=tzxlsjzg(:,Nzhizuo+1:6*NN);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
draw(jiedian,dangyuan,tzxlsjzg1,1)%%第一阶振型图,调整最后一个实参可以得到其他阶振型。

结果

输入文件为"最新数据1.txt",路径要与主程序中的路径匹配,内容如下

31.3      0.05    1024    11.6    8       21      6.28318 15      5
71
0   0   0   20  0
4   0   0   19  0
8   0   0   18  0
12  0   0   17  0
16  0   0   16  0
20  0   0   15  0
24  0   0   14  0
28  0   0   13  0
32  0   0   12  0
36  0   0   11  0
40  0   0   10  0
43.5    0   0   9   0
47  0   0   8   0
50.5    0   0   7   0
54  0   0   6   0
57.5    0   0   5   0
61  0   0   4   0
64.5    0   0   3   0
65.5    0   0   2   0
68  0   0   1   0
69  0   0   1   0
70  0   0   1   0
72  0   0   1   0
74  0   0   1   0
75  0   0   1   0
76  0   0   1   0
78.5    0   0   2   0
79.5    0   0   3   0
83  0   0   4   0
86.5    0   0   5   0
90  0   0   6   0
93.5    0   0   7   0
97  0   0   8   0
100.5   0   0   9   0
104 0   0   10  0
108 0   0   11  0
112 0   0   12  0
116 0   0   13  0
120 0   0   14  0
124 0   0   15  0
128 0   0   16  0
132 0   0   17  0
136 0   0   18  0
140 0   0   19  0
144 0   0   20  0
69  0   -8.8    21  1
69  0   -11.8   21  1
69  0   -14.8   21  1
69  0   -17.8   21  1
69  0   -21.8   21  1
69  0   -25.8   21  1
69  0   -27.8   21  1
69  0   -29.8   21  1
69  0   -31.8   21  1
69  0   -33.8   21  1
69  0   -37.8   21  1
75  0   -8.8    23  2
75  0   -11.8   23  2
75  0   -14.8   23  2
75  0   -17.8   23  2
75  0   -21.8   23  2
75  0   -25.8   23  2
75  0   -27.8   23  2
75  0   -29.8   23  2
75  0   -31.8   23  2
75  0   -33.8   23  2
75  0   -37.8   23  2
70  0   -17.8   22  -1
74  0   -17.8   22  -1
70  0   -27.8   22  -1
74  0   -27.8   22  -1
45
2
11  11
-29.8   -29.8
72
1   2   1   0
2   3   1   0
3   4   1   0
4   5   1   0
5   6   1   0
6   7   1   0
7   8   1   0
8   9   1   0
9   10  1   0
10  11  1   0
11  12  1   0
12  13  1   0
13  14  1   0
14  15  1   0
15  16  1   0
16  17  1   0
17  18  1   0
18  19  1   0
19  20  1   0
20  21  1   0
21  22  1   0
22  23  1   0
23  24  1   0
24  25  1   0
25  26  1   0
26  27  1   0
27  28  1   0
28  29  1   0
29  30  1   0
30  31  1   0
31  32  1   0
32  33  1   0
33  34  1   0
34  35  1   0
35  36  1   0
36  37  1   0
37  38  1   0
38  39  1   0
39  40  1   0
40  41  1   0
41  42  1   0
42  43  1   0
43  44  1   0
44  45  1   0
46  47  1   0
47  48  1   0
48  49  1   0
49  50  1   0
50  51  1   0
51  52  1   0
52  53  1   0
53  54  1   0
54  55  1   0
55  56  1   0
57  58  1   0
58  59  1   0
59  60  1   0
60  61  1   0
61  62  1   0
62  63  1   0
63  64  1   0
64  65  1   0
65  66  1   0
66  67  1   0
49  68  1   0
68  69  1   0
69  60  1   0
52  70  1   0
70  71  1   0
71  63  1   0
21  46  1   0
25  57  1   0
6
65      67      68      70      71      72
12
56  1   0
56  2   0
56  3   0
56  4   0
56  5   0
56  6   0
67  1   0
67  2   0
67  3   0
67  4   0
67  5   0
67  6   0
23
38.725  15.295  22.389  404.427 343.054 252.508 5.800   5.800   4.465   4.335   17.304  17.113  39.831  19.866  5.800   4.335   -5.800  4.465   5.800   4.465   3.500   -4.335  -3.500  -4.335
28.405  10.158  15.577  315.093 279.262 215.197 5.800   5.800   4.517   4.283   20.205  22.678  39.831  22.777  5.800   4.283   -5.800  4.517   5.800   4.517   3.500   -4.283  -3.500  -4.283
28.028  10.116  15.31   306.713 267.434 212.508 5.8 5.8 4.436   4.228   19.647  22.68   39.559  22.547  5.8 4.228   -5.8    4.436   5.8 4.436   3.5 -4.228  -3.5    -4.228
26.75   9.96    14.423  278.857 229.828 203.419 5.8 5.8 4.162   4.043   17.812  22.7    38.641  21.773  5.8 4.043   -5.8    4.162   5.8 4.162   3.5 -4.043  -3.5    -4.043
25.555  9.803   13.584  253.223 197.825 194.91  5.8 5.8 3.907   3.868   16.169  22.715  37.781  21.047  5.8 3.868   -5.8    3.907   5.8 3.907   3.5 -3.868  -3.5    -3.868
24.439  9.638   12.797  229.612 170.559 186.943 5.8 5.8 3.669   3.703   14.697  22.719  36.975  20.365  5.8 3.703   -5.8    3.669   5.8 3.669   3.5 -3.703  -3.5    -3.703
23.397  9.462   12.056  208.058 147.369 179.508 5.8 5.8 3.448   3.548   13.38   22.726  36.223  19.729  5.8 3.548   -5.8    3.448   5.8 3.448   3.5 -3.548  -3.5    -3.548
19.79   9.099   8.709   173.62  121.611 155.516 5.8 5.8 3.251   3.397   15.115  20.098  35.527  20.141  5.8 3.397   -5.8    3.251   5.8 3.251   3.5 -3.397  -3.5    -3.397
19.035  8.894   8.218   157.754 105.993 150.112 5.8 5.8 3.057   3.271   13.848  20.152  34.887  19.601  5.8 3.271   -5.8    3.057   5.8 3.057   3.5 -3.271  -3.5    -3.271
18.348  8.725   7.764   143.753 92.858  145.176 5.8 5.8 2.882   3.153   12.732  20.195  34.301  19.105  5.8 3.153   -5.8    2.882   5.8 2.882   3.5 -3.153  -3.5    -3.153
17.637  8.56    7.335   130.125 80.4    140.079 5.8 5.8 2.702   3.031   11.618  20.251  33.697  18.595  5.8 3.031   -5.8    2.702   5.8 2.702   3.5 -3.031  -3.5    -3.031
17.012  8.4 6.933   118.169 70.334  135.595 5.8 5.8 2.544   2.923   10.673  20.299  33.165  18.145  5.8 2.923   -5.8    2.544   5.8 2.544   3.5 -2.923  -3.5    -2.923
16.475  8.246   6.571   107.939 62.296  131.725 5.8 5.8 2.41    2.827   9.884   20.337  32.705  17.755  5.8 2.827   -5.8    2.41    5.8 2.41    3.5 -2.827  -3.5    -2.827
16.017  8.113   6.288   99.609  55.935  128.439 5.8 5.8 2.296   2.746   9.232   20.376  32.315  17.425  5.8 2.746   -5.8    2.296   5.8 2.296   3.5 -2.746  -3.5    -2.746
13.752  7.856   4.236   83.764  48.674  111.326 5.8 5.8 2.171   2.712   12.139  17.787  31.997  18.155  5.8 2.712   -5.8    2.171   5.8 2.171   3.5 -2.712  -3.5    -2.712
13.508  7.763   4.108   79.388  45.197  109.654 5.8 5.8 2.097   2.662   11.581  17.853  31.749  17.947  5.8 2.662   -5.8    2.097   5.8 2.097   3.5 -2.662  -3.5    -2.662
13.342  7.701   4.019   76.364  42.852  108.488 5.8 5.8 2.046   2.626   11.2    17.885  31.573  17.797  5.8 2.626   -5.8    2.046   5.8 2.046   3.5 -2.626  -3.5    -2.626
13.241  7.663   3.965   74.548  41.472  107.783 5.8 5.8 2.015   2.604   10.971  17.907  31.467  17.707  5.8 2.604   -5.8    2.015   5.8 2.015   3.5 -2.604  -3.5    -2.604
13.205  7.653   3.946   73.963  41.002  107.539 5.8 5.8 2.004   2.596   10.891  17.919  31.431  17.677  5.8 2.596   -5.8    2.004   5.8 2.004   3.5 -2.596  -3.5    -2.596
13.205  7.653   3.946   73.963  41.002  107.539 5.8 5.8 2.004   2.596   10.891  17.919  31.431  17.677  5.8 2.596   -5.8    2.004   5.8 2.004   3.5 -2.596  -3.5    -2.596
16.000  13.333  13.333  17.974  5.333   85.333  4.000   4.000   1.000   1.000   0.500   8.000   20.000  0.000   4.000   1.000   -4.000  1.000   4.000   1.000   4.000   -1.000  -4.000  -1.000
4.800   4.000   4.000   0.938   0.256   14.400  3.000   3.000   0.400   0.400   0.080   4.500   13.600  0.000   3.000   0.400   -3.000  0.400   3.000   0.400   3.000   -0.400  -3.000  -0.400
16.000  13.333  13.333  17.974  5.333   85.333  4.000   4.000   1.000   1.000   0.500   8.000   20.000  0.000   4.000   1.000   -4.000  1.000   4.000   1.000   4.000   -1.000  -4.000  -1.000
2.174   -0.431  -0.334  2.253   -0.534  -0.330  2.327   -0.628  -0.324  -2.188  2.824   -0.141
2.174   -0.431  -0.334  2.253   -0.534  -0.330  2.327   -0.628  -0.324  -2.188  2.824   -0.141
2.174   -0.431  -0.334  2.253   -0.534  -0.330  2.327   -0.628  -0.324  -2.188  2.824   -0.141
2.028   -0.384  -0.311  2.101   -0.479  -0.304  2.174   -0.582  -0.298  -2.083  2.833   -0.185
1.921   -0.397  -0.295  1.986   -0.496  -0.287  2.045   -0.591  -0.279  -1.772  2.780   -0.227
1.802   -0.381  -0.286  1.864   -0.473  -0.273  1.915   -0.583  -0.264  -1.614  2.893   -0.320
1.700   -0.393  -0.277  1.754   -0.502  -0.266  1.801   -0.595  -0.258  -1.449  2.899   -0.276
1.612   -0.393  -0.262  1.661   -0.492  -0.251  1.710   -0.595  -0.239  -1.404  2.892   -0.334
1.538   -0.390  -0.265  1.586   -0.494  -0.251  1.633   -0.601  -0.239  -1.365  3.014   -0.365
1.437   -0.404  -0.252  1.480   -0.511  -0.239  1.521   -0.613  -0.225  -1.210  2.996   -0.395
1.394   -0.410  -0.240  1.434   -0.514  -0.226  1.475   -0.610  -0.212  -1.160  2.867   -0.402
1.339   -0.392  -0.232  1.375   -0.496  -0.218  1.410   -0.592  -0.204  -1.013  2.866   -0.411
1.288   -0.371  -0.235  1.322   -0.473  -0.220  1.357   -0.568  -0.205  -0.986  2.826   -0.425
1.231   -0.367  -0.242  1.262   -0.468  -0.228  1.297   -0.571  -0.214  -0.945  2.918   -0.407
1.217   -0.370  -0.228  1.250   -0.472  -0.213  1.283   -0.569  -0.197  -0.958  2.856   -0.441
1.192   -0.355  -0.230  1.226   -0.459  -0.213  1.261   -0.560  -0.198  -0.986  2.928   -0.459
1.177   -0.378  -0.228  1.209   -0.480  -0.212  1.239   -0.573  -0.196  -0.891  2.807   -0.457
1.164   -0.377  -0.225  1.195   -0.479  -0.208  1.224   -0.573  -0.192  -0.858  2.816   -0.467
1.108   -0.401  -0.226  1.131   -0.496  -0.211  1.160   -0.594  -0.195  -0.752  2.769   -0.449
1.108   -0.401  -0.226  1.131   -0.496  -0.211  1.160   -0.594  -0.195  -0.752  2.769   -0.449
0.245   -0.016  0.252   0.257   0.111   0.208   0.266   0.168   0.166   0.309   2.639   -1.232
0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000   0.000
0.261   -0.147  0.038   0.254   -0.074  -0.007  0.239   0.064   -0.058  -0.313  3.027   -1.375
1
36000000000  15430000000   2650
2
21      90000
25      90000

运行结果如下图示:


还可以查看其他振型,以及频率。


前十阶频率为:
1.98871609035383
4.42377330320088
6.14903626324008
8.79482569837443
9.72747024277138
14.7595719825660
28.5067851469935
31.1482902649112
36.3710508358691
54.6773606580982

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