Application of the Cubic Polynomial Strength Criterion to the Failure Analysis of Composite Materials

Abstract

A comparative failure analysis is presented based on the application of quadratic and cubic forms of the tensor polynomial lamina strength cri terion to various composite structural configurations in a plane stress state. Failure loads have been predicted for off-angle laminates under simple loading conditions and for symmetric-balanced laminates subject to varying degrees of biaxial tension, including configurations subject to multimode failures. Some experimental data are also provided to support these calcula tions. From these results, the necessity of employing a cubic strength criterion to accurately predict the failure of composite laminae is demon strated.