Failure Analysis of Adhesively Bonded Composite Joints

Failure analysis of bonded composite joints is essential to the design of modern aerospace vehicles in which adhesive joints are widely used. Recently, methods for stress and failure analysis of composite bonded joints have been developed in a new HyperSizer® capability. The first part of the capability involves calculation of adhesive stresses, as well as detailed in-plane and out-of-plane stresses in the adherends, as described in ref. 1. This companion paper presents the second major part, which is the prediction of failure of bonded joints and validation of those predictions. Many leading bonded joint failure theories, summarized herein, were implemented, and then evaluated for accuracy against test data. Through comparison to 14 test cases with 3 different joint configurations, the ratios of predicted failure load divided by test average failure load vary from 0.77 to 0.95. These results show that HyperSizer is relatively accurate and consistent for predicting initial failure.