Loads Moving on Beam Supported by Layered Elastic Foundation

Abstract

A finite element method is applied to analyze the dynamic response of a beam supported by layered inertial foundation and subjected to moving loads. The foundation is represented by the modified Pasternak model or by the Winkler model. The moving loads are simulated by a concentrated force, a point-mass or a spring-mass-damper system. The equations of motion are represented by a system of second-order ordinary differential equations with variable coefficients. Newmark’s method of constant average acceleration is used to integrate these equations. Two test cases are analyzed for numerical illustration. In the first case, the dynamic response of a beam supported by the modified Pasternak model and subjected to a moving concentrated force is analyzed. In the second, the dynamic response of a beam supported by the Winkler model and subjected to a moving spring-mass-damper system is analyzed. The results from these two cases are compared with those obtained by the transfer matrix method.