Buckling Analysis of Woven Glass Epoxy Laminated Composite Plate

Abstract

There have been numerous studies on the composite laminated structures which find many applications in many engineering fields namely aerospace, biomedical, civil, marine and mechanical engineering because of their ease of handling, good mechanical properties and low fabrication cost. They also possess excellent damage tolerance and impact resistance. The mechanical behaviour of composite structures is of particular interest to engineers in modern technology. Buckling of plates is a well-established branch of research in composite structures stability. It has a wide range of applications in engineering science and technology. Buckling behaviour of laminated composite plates subjected to in-plane loads is an important consideration in the preliminary design of aircraft and launch vehicle components. The sizing of many structural subcomponents of these vehicles is often determined by stability constraints. Plates with circular holes and other openings are extensively used as structural members in aircraft design. The buckling behaviour of such plates has always received much attention by researchers. These holes can be access holes, holes for hardware to pass through, or in the case of fuselage, windows and doors. In some cases holes are used to reduce the weight of the structure. In aerospace and many other applications these structural components are also made up of composite material to further reduce the weight of the structure. The outstanding mechanical properties of composite structures, such as durability and corrosion-resistance characteristics combined with low density, make it more attractive compared to conventional materials.

In this study, the influence of cut-out shape, length/thickness ratio, and ply orientation and aspect ratio on the buckling of woven glass epoxy laminated composite plate is examined experimentally. Clamped –free -Clamped-free boundary condition is considered for all case. Experiments have been carried out on laminated composites with circular, square and rectangular cut-outs. The thickness of the plate was changed by increasing the number of layers. After the buckling experiments micro electroscopic scanning was performed for the failed specimens. Comparisons are made between the test results, by using two different approach. The results shows effect of various cut-out shapes, orientation of fiber, aspect ratio and length to thickness ratio on the buckling load.