An investigation of failure criterion with stress concentrations for orthotropic composite materials

The purpose of this thesis is to further develop the Yeh-Stratton (Y-S) failure criterion for the application to composite laminates. In this study, the failure analysis of notched orthogonal composite laminates under uniaxial tensile loading is examined with the Yeh-Stratton criterion. The Yeh-Stratton failure predictions are compared to several other fracture criteria such as; Tsai-Hill, Tsai-Wu, Cowin, Hoffman, Fischer, Chang and Chang, Hashin and Rotem Criterion, and finally Hashin.; The materials being examined are fiber-reinforced orthotropic composites, each with a central crack. The first material in this study is a ceramic matrix composite (CMC) of interest in the aerospace industry. The second material in this study is a graphite/epoxy AS4/3502 [0/902/0].; Testing of both fiber reinforced CMC [0/90] and AS4/3502 [0/902 /0] laminates containing central cracks and under tensile loading conditions were analytically investigated by the failure criteria and evaluated against the experimental results.; In this thesis, the Yeh-Stratton criterion was employed and compared with several other popular failure theories. The Yeh-Stratton criterion proved, in this study, to be an accurate means of predicting the fracture stress of a notched orthogonal composite laminate.