6-dof系统的模型，质量/刚度/阻尼矩阵等，见下面日志：

Case II – Non-Proportional Damping (c1= 5.1 N/m/s; c2=7.5 N /m/s; c3=3.9 N/m/s; c4=4.3 N/m/s; 
c5=2.96 N/m/s; c6=4.32 N/m/s;c7=3.65 N/m/s; c8=0.58 N/m/s; c9=2.85 N/m/s; c10=0.37 N/m/s)

给出数值解：

lambda_1~6：

         -0.120461482039616 +      22.0277474238835i

         -0.340083552651792 +      34.5143994730703i

         -0.401742149194278 +      40.3810636308249i

         -0.448060400857154 +      47.4479807905313i

         -0.836825213304668 +      52.6954978324238i

          -1.66132720195092 +      79.4042635550371i

 

对应的6阶模态频率，模态阻尼为：

Order	Modal freq.   / Hz	Damping ratio   / %
1	3.50587730964481	0.546854285688703
2	5.49340393947853	0.985290342110243
3	6.4271639349108	0.994828349489089
4	7.55191737690531	0.944277115878282
5	8.38780640608438	1.58783909348167
6	12.6403467733154	2.09178150746386

 

对应的6阶模态振型为：

比例阻尼情形，见下面日记链接：