the current building codes provide limited prescriptive guidance on design for protection of buildings due to progressive collapse. progressive collapse is a situation in which a localized failure in a structure, caused by an abnormal load, such as explosions or other happenings. three procedures, often employed for determination of the structural response during progressive collapse i.e. linea...

In this paper, a new stage structured prey-predator model with linear functional response is proposed and studied. The stages for prey have been considered. The proposed mathematical model consists of three nonlinear ordinary differential equations to describe the interaction among juvenile prey, adult prey and predator populations. The model is analyzed by using linear stability analysis to ob...

In this paper, the nonlinear vibration of functionally graded (FGM) cylindrical shells subjected to radial harmonic excitation is investigated. The nonlinear formulation is based on a Donnell’s nonlinear shallow-shell theory, in which the geometric nonlinearity takes the form of von Karman strains. The Lagrange equations of motion were obtained by an energy approach. In order to reduce the syst...

Nonlinear Time History (NTH) analysis is currently the most reliable method for estimating structural behavior. Considerable computational demand and complexity of this method may cause difficulty for its routine practical application. Based on the Methodology of Endurance Time (ET) method, it can estimate the nonlinear response of structures with a much lower computational cost. In this resear...

Irregular buildings make up a large portion of  urban infrastructure. Presence of irregularities can be due to architectural and  user changes in building stories. Main objective of this article is evaluate seismic performance of structures with vertical irregularities. Seismic responses are obtained by enveloping peak inelastic responses resulting from pushover analyses according to provided p...