Dynamic response of plates on elastic foundation under eccentric impact load

Building and Construction Engineering Department, University of Technology, Baghdad, Iraq

^* Corresponding author: myf_1968@yahoo.com

Abstract

In this study, nonlinear three-dimensional finite element analysis has been used to conduct a numerical investigation of the effect of applied impact load on the foundation based on sandy soil using the finite element method by ANSYS (Version 11) computer program. The 8-node brick elements are used to model the concrete of foundation and the soil under the foundation which are denoted by Solid 65 for concrete and Solid 45 for the soil while the interface is modeled by using three-dimensional surface-to-surface (Target 170 and Contact 174) contact elements connected with concrete and soil. As a case study, a square concrete foundation with dimensions of 3×3×0.3 m placed on the foundation soil 15 m deep and 9 m away from the edge of plate is subjected to impact load. A parametric study is carried out to investigate the effect of several parameters including: foundation thickness, load eccentricity and amplitude of impact load. It was concluded that the load eccentricity increases the displacement and decreases the stress at the foundation center. This is attributed to non-uniformly distributed stresses on the loaded area, where the loads are concentrated locally within the loaded area. The presence of damping leads to a considerable decrease in the foundation displacements and stresses. The increase in the damping ratio reduces the vertical displacement of the foundation at the same time at all damping ratios.