Buckling Analysis of Laminar Composite Plates with Holes

Abstract

Laminated composite plates are made up of plates consisting of layers bonded together and made up of materials chemically different from each other but combined macroscopically. These have an application in aircrafts, railway coaches, bridges et cetera because they are easy to handle, have got improved properties and the cost of their fabrication is low. But their failure can lead to catastrophic disasters. And generally the failure of these structures is due to the combined effect of excessive stresses on it and buckling. Hence the buckling behavior of these kinds of plates should be analyzed properly. Buckling behavior of laminated composite plates subjected to in-plane loads is an important aspect in the preliminary design of aircraft and launch vehicle components. Holes are provided either in the center or elsewhere in the laminar plates for the purpose of pipes for electric cables or other purposes. Due to the presence of holes in the plates, the stress concentration is near to the holes and the stiffness of the plates is reduced. Hence the study is important in order to know the buckling behavior of such plates. In this study, the effect of cut-out, its shape, different boundary conditions, length/thickness ratio, stacking sequence, and ply orientation has been studied. Analysis was carried out with laminated composite plates with circular, square and triangular cut-outs. Results show the effect of different cut-out shapes, different boundary conditions, orientation of layers and length/thickness ratio on the buckling load.