Stress Resultant and Moment Around Holes in Unsymmetrical Laminated Composite Plates Subjected to Remote Uniform Loading

Abstract

In the modern era of technology, for aircrafts, space vehicles, under water transporta- tion and many other lightweight applications, composite laminates are widely used. The key feature of these laminates are that their strength and sti ness properties can be tailored to meet the design requirements. Holes and cut-outs are bound to be present in many engineering structures, which cause serious problems of stress concentrations. These hole/opening works as stress raisers and may lead to the failure of the structure/machine component. In present work a general solution for bending of laminates with circular, elliptical and square hole is presented using Muskhelisvili's stress function. The e ect of hole geometry, loading condition, ber orientation, stacking sequence, material parameters on stress concentration is studied through numerical results obtained for materials like Graphite/epoxy, Boron/epoxy, Glass/epoxy and Graphite/BMI. The behavior of unsymmetric laminate is di erent from symmetric laminates. The generalized solution for unsymmetric plate subjected to bending at in nity is ob- tained. The stress concentration around circular and elliptic holes on di erent condi- tion is reported. Signi cant bending extensional coupling is evident which e ects the stress eld.