ABSTRACT

Rayleigh damping model, which is still adopted by many general finite element programs and widely used in analysis of engineering, leads to the inconformity of the calculating modal damping ratio with the actual modal damping ratios. The appropriate Rayleigh damping matrix is significant for accurate dynamic response analysis of complicated field. This paper establishes a
dual parameter optimization theory for calculation of Rayleigh damping coefficients. The functional relation between the relative error of dynamic response and Rayleigh damping coefficients is established based on CQC method. By taking the square sum of the errors of peak value of displacement and the error of peak value of acceleration at the multiple points (DOF) of the surface of the complex site as the control objective, the equations for solving Rayleigh damping coefficients are obtained based on the principle of minimizing the control objective. Then, as an example, the seismic response of a valley under the excitation of 28 representative seismic waves which are randomly selected is calculated and the error due to Rayleigh damping model is analysed. The numerical result verifies the accuracy and applicability of the proposed method.