Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Elastic Foundation

Behavior of Plate on Elastic Foundation under Impact Load

Mohammed Y. Fattah; Mohammed J. Hamood; Sura A. Abbas

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 1007-1027

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 represent the concrete of foundation and the soil under the foundation which are denoted by Solid 65 for concrete and Solid 45 for the soil and 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 concrete foundation with dimensions (3×3×0.3) m placed on the soil 15 m deep and 9 m away from the edge of foundation is subjected to impact load. A parametric study is carried out to investigate the effect of several parameters including: foundation dimensions (geometry) and amplitude of impact load.
It was concluded that as the foundation thickness increases, the time for maximum displacement to take place increases due to geometrical damping induced by the foundation. When the length of foundation increases, the oscillation of vertical displacement decreases, which means that the foundation becomes more stable.

Simulation of Behavior of Plate on Elastic Foundation under Impact Load by the Finite Element Method

Mohammed Y. Fattah; Mohammed J. Hamood; Sura Amoori Abbas

Engineering and Technology Journal, 2013, Volume 31, Issue 19, Pages 44-58

Transient response and vibrations of an elastic plate resting on sandy soil are presented. Plates are commonly used structural elements and are subjected to wide variety of static and dynamic loads. Such studies are of particular interest in analytical investigations related to structural foundation on soil media. The influence of impact induced high strain-rates within the structure, which causes property changes in all used materials, has to be regarded according to experimental results.
The main objective of the present paper, using the finite element approach through ANSYS program is the simulation of the dynamic response of the foundation under impact load. As a case study, previous experimental work included application of a dynamic load generated by dropping a steel ball (38.1 mm in diameter, 2.22 N in weight) from a height of 609.6 mm onto an aluminum target plate (203.2 mm in diameter, 12.7 mm thick) placed on top of a sand medium. The impact load is defined as a product of the loading magnitude and a time varying function which is assumed to be a Hanning's function for a monopeak, smooth-shaped curve. The problem is discretised by using four types of elements; Solid 45 to model the soil, Shell 63 to model the aluminum plate and Target 170 and Contact 174 are used to model the contact between the plate and soil. Shell 63 (elastic shell) has both bending and membrane capabilities.
It is noticed that the finite element analysis agrees well with the experimental results throughout the entire range of behavior, and the difference in the ultimate displacement is about 6.2%. It can be concluded that ANSYS program is well suited for impact analyses of soil and structural dynamics problems in the non-linear range.