Probe into Dynamic Condensation Technique for Computing Several Low Order Modal Pairs 

Author  WangZhengGuo 
Tutor  WangXiaoHong 
School  Nanjing University of Aeronautics and Astronautics 
Course  Computational Mathematics 
Keywords  structural finite element model generalized eigenvalue dynamic condensation method subspace iteration method matrix equation 
CLC  O302 
Type  Master's thesis 
Year  2006 
Downloads  99 
Quotes  0 
Reducing the order of a large structural finite element model is important in improving the efficiency of finite element analysis in the field of structural dynamics and vibration. This has been broadly applied to many fields such as structural damage detection, parameter identification, testanalysis model correlation, modal testing, dynamic substructure technique and so on.In 1965,static reduction was proposed by Guyan and Irons(reduction method).After that,a lot of work have been done in this area and many efficient static and dynamic condensation methods have been proposed., The dynamic condensation method, started in early 1990’s, is a widelyadopted effective method for order reduction.dynamic condensation technique has been improved and consummated in the following areas.1. A study was presents on the convergence property of computing the few lowest eigenpairs in large finite element models using dynamic condensation method. Using the power series expansion of the matrix. And two numerical examples have demonstrated that influence the calculating precision if the master and slave DOFs are not separated appropriately.2 This paper studies the convergence property of the dynamic condensation method on computing the few lowest eigenpairs in large finite element models. And a sufficient condition of the method is derived by the theoretical part solving matrix equation.3.The key characteristics and effectiveness of the dynamic condensation method are further illustrated by comparing with the subspace iteration method.