عنوان مقاله [English]
A fast and efficient numerical scheme is presented for time-history analysis of single-degree-of-freedom (SDOF) structural systems undergoing seismic excitation. The new method is called Newton-Cotes-4P-θ Method. It uses the most known 4-point Newton-Cotes quadrature in its body to solve the vibration equation. Nonlinear analysis is covered as well as linear analysis. Any arbitrary external loadings of type force or seismic signals are welcome. The significant advantageous of the new formulation is its great simplicity, running speed and appropriate precision level compared with its counterpart such as Duhamel integral and Newmark-β methods. The accuracy level of the Newton-Cotes-4P-θ is close to the semi-analytical method of Duhamel integration and its speed is similar to the Newmark-β algorithm. Notably, against nonlinear Newmark-β method, the new method does not require a standalone procedure to handle nonlinear analysis; instead, it simply triggers iteration of the same computation used in its first processing round. Moreover, Newmark-β method lose its performance dealing with stiff ("T" _"n" " < 0.15 sec" ) and near-conservative ("ζ < 0.02" ) systems; however, Newton-Cotes-4P-θ method does not loos its accuracy and keep its well-performed analysis in this cases. Numerical results reveal the superiority of Newton-Cotes- 4P-θ method against its counterparts such as Duhamel integral, Newmark-β and Wilson-θ methods.