Table of Contents
Journal of Structures
Volume 2013 (2013), Article ID 492839, 6 pages
http://dx.doi.org/10.1155/2013/492839
Research Article

Parametric Instability of Square Laminated Plates in Hygrothermal Environment

Department of Civil Engineering, National Institute of Technology, Rourkela, Orissa 769008, India

Received 29 April 2013; Accepted 8 July 2013

Academic Editor: Mustafa Kemal Apalak

Copyright © 2013 Manoj Kumar Rath and Shishir Kumar Sahu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The present paper investigates the parametric instability of square laminated plates subjected to periodic dynamic loadings in hygrothermal environment. The effects of various parameters like the increase in static load factor and the degree of orthotropy of simply supported composite plates at elevated temperatures and moisture concentrations on the principal instability regions are investigated using finite element method. The effects of transverse shear deformation and rotary inertia are used to study the antisymmetric angle-ply square plates. A simple laminated plate model is developed for the parametric instability of square laminated plates subjected to hygrothermal loading. A computer program based on FEM in MATLAB environment is developed to perform all necessary computations. The results show that instability of square laminated plates occurs for different parameters with an increase in temperature and moisture environment. The onset of instability occurs earlier, and the width of dynamic instability regions increases with a rise in temperature and moisture for different parameters. The effect of damping shows that there is a finite critical value of dynamic load factor for each instability region below which the square laminated plates cannot become unstable.