Comparison of Bending Response of Laminated Composite Plates under Mechanical and Hygro-Thermal Loading

In recent years many researches in deformation and stress analysis of laminated composite plate subjected to moisture and temperature has been conducted but the study has focused mainly in the effect of the temperature on the composite plate. Temperature and moisture variation is always an important factor to be considered in designing any parts of an aircraft, which may sometimes lead to catastrophic effects if these are not given proper consideration while designing. Composites are subjected to varied environmental conditions during the service life. Moisture and temperature have an unfavorable effect on the performance of composites. Stiffness and strength are reduced in proportion to increase in moisture concentration and temperature. In the present investigation, the quadratic iso-parametric plate bending element is applied to study the effect of moisture and temperature on the bending behavior of laminated composite plates. A Matlab code is generated to first find the deflection and stress in a composite plate when the environmental effect is not considered and in second case the variation of moisture and temperature is taken into account and its deflection and moments are found out and compared with the open source research journals. Reduced lamina material properties at elevated moisture concentration and temperature are used in the analysis. Deflections and stress resultants are evaluated for angle-ply and anti-symmetric cross ply laminates at different moisture concentrations and temperatures for clamped and simply-supported boundary conditions and their distribution in the plate is studied. In case of anti-symmetric angle-ply laminates, fiber orientation is also considered.