NONLINEAR DAMPED SEISMIC RESPONSE ANALYSIS OF PLANE SOLID STRUCTURES USING AN IMPLICIT DYNAMIC FINITE ELEMENT ALGORITHM

Abstract

An implicit dynamic finite element algorithm with decoupled equations is proposed to simulate the nonlinear damped behavior of plane solid structures subjected to strong earthquake excitations. The approach employs equivalent nodal secant stiffness and damping coefficients to decouple the dynamic equilibrium equations, thereby eliminating the need for triangular factorization of the coefficient matrix. Additionally, an efficient method is introduced to rapidly evaluate stiffness-proportional damping forces at the element level when the structure undergoes highly nonlinear dynamic responses. In this approach, the rigid body motion of the plane element is accurately identified, and the pure deformation velocity is then used to compute the nodal damping forces. Compared to conventional finite element dynamic analysis methods, the proposed algorithm demonstrates both high accuracy and computational efficiency in simulating nonlinear damped responses of plane solid structures under seismic loading.