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 extended to nonviscous damping system for modal parameter identification and relaxation parameter calculation. The state space formulation is used to express the equation of motion with nonviscous damping. The proposed method establishes a nonlinear relationship between the eigenvalues and the damping parameters of a nonviscous damping system. The accuracy of the method is verified through numerical examples.