Superposition Method for Analysis of Free-Edge Stresses

Abstract

Superposition techniques were used to transform the edge stress problem for com posite laminates into a more lucid form. By eliminating loads and stresses not con tributing to interlaminar stresses, the essential aspects of the edge stress problem are easily recognized. Transformed problem statements were developed for both mechan ical and thermal loads. Also, a technique for approximate analysis using a two- dimensional plane strain analysis was developed. Conventional quasi-three-dimensional analysis was used to evaluate the accuracy of the transformed problems and the ap proximate two-dimensional analysis. The transformed problems were shown to be ex actly equivalent to the original problems. The approximate two-dimensional analysis was found to predict the interlaminar normal and shear stresses reasonably well.