Structural Engineering and Mechanics
Volume 39, Number 5, 2011, pages 703-716
DOI: 10.12989/sem.2011.39.5.703
Dynamic analysis of structures in frequency domain by a new set of Ritz vectors
S. Aliasghar Arjmandi and Vahid Lotfi
Abstract
The accurate dynamic analysis of structures is usually performed by a fine finite element discretization with very large number of degrees of freedom. Apart from modal analysis, one can reduce the number of final equations by assuming the deformed shape of the structure as a linear combination of independent Ritz vectors. The efficiency of this method relies heavily on the vectors selected. In this
paper, a new set of Ritz vectors is proposed. It is primarily proved that these vectors are linearly independent. Subsequently, various two and three-dimensional examples are analyzed based on the proposed method. In each case, the results are compared with the ones obtained based on usual Ritz and modal analysis methods. It is finally concluded that the proposed method is very effective and efficient method for dynamic analysis of structures in frequency domain.
Key Words
Ritz vectors; structural dynamics; frequency domain analysis; DOF reduction methods; linearly independent vectors; convergence of Ritz method
Address
S. Aliasghar Arjmandi and Vahid Lotfi: Civil Engineering Department, Amirkabir University of Technology, Tehran, Iran