Naval Undersea Warfare Center Division Newport United States
Fiber-reinforced polymers FRPs-composites consisting of a thermoset or thermoplastic polymer matrix reinforced by carbon, glass oraramid fibers-have been used as a substitute for more conventional materials in a wide range of applications, particularly in the aerospace,defense, and automobile industries. Because of the widespread availability of measurement techniques, experimental testing of composite materials has largely outpaced the computational modeling ability, forcing design of composite structures to follow a build-test-build cycle.The use of the extended finite-element method XFEM has revolutionized the computational design process it improves modeling efficiency and allows previously unfeasible analyses of complex failure mechanisms to be investigated.To establish confidence in any new computational technique, however, it is imperative that computational results be compared with experimental test results to validate the analytical models. The research documented in this report clearly demonstrates the ability of XFEM to model various modes of failure in composite materials while taking into account composite layer-orientation-dependent fracture properties. Comparisons between experimental and computational results show that XFEM successfully replicates the failure mechanisms of composite cylinders under lateral compression. With proper material property characterization, better confidence can be gained inutilizing efficient computational analysis tools such as XFEM in the design of previously untested composite arrangements, reducing costand time requirements.