An Eigensystem Realization Algorithm for Identification of Modal Parameters of Nonviscous Damping Structure System

In this paper, a modified eigensystem realization algorithm for modal parameter identification and relaxation parameter is extended from a viscous damping system to a nonviscous damping system. The equation of motion with nonviscous damping in second-order form is expressed in the state space formulation. The eigenvalues of the second-order form equation are proved equal to the state space formulation. The extended method is based on the proposed nonlinear relationship between the eigenvalues and the damping parameters of a nonviscous damping system. The identified procedure of the proposed method is given in detail. Finally, the method is validated using three numerical examples for assessing its accuracy.

Automated summary

In this paper, a modified eigensystem realization algorithm is applied to identify modal parameters and relaxation parameters in nonviscous damping systems. The equation of motion with nonviscous damping is transformed into the state space formulation, and the equality between the eigenvalues of the second-order equation and the state space formulation is proved. The proposed method utilizes a nonlinear relationship between the eigenvalues and the damping parameters of the nonviscous damping system. The accuracy of the method is validated through three numerical examples.