Thick Composite Crack Analysis Navy SBIR FY2013.2 Sol No.: Navy SBIR FY2013.2 Topic No.: N132-101 Topic Title: Thick Composite Crack Analysis Proposal No.: N132-101-0754 Firm: Global Engineering Research and Technologies 2845 E. 2nd Street Tucson, Arizona 85716-4108 Contact: Ali Boufelfel Phone: (520) 561-5724 Abstract: Advanced thick composites are increasingly used in components for defense applications as well as commercial structures. Component level structural testing and analysis of advanced composites is prohibitively expensive and time consuming. Instead, using robust and accurate computational tools complemented by experiments at key stages is a viable and cost-effective option. The proposed project will advance structural methods and material technologies that enable reliable assessment of capability and useful life of composite aircraft flight-critical components and structures. The physics-based peridynamics (PD) methodology overcomes the weaknesses of the existing methods, and it is capable of identifying all of the failure modes without simplifying assumptions. The PD methodology effectively predicts complex failure in composite structures under general dynamic and static loading conditions. Damage is inherently calculated in a PD analysis without special procedures, making progressive failure analysis more practical. This results in a more efficient and cost effective design that meets reliability goals. The proposed approach will also replace some of the coupon-level tests used in the material qualification with computational models (virtual tests) validated with empirical data (measurement.). Such techniques will advance our ability to predict material behavior and enable affordable qualification of composite materials for structural applications. Benefits: The proposed project will lead to a predictive capability for improving structural designs and life predictions of advanced thick composite parts in defense vehicles in particular with rotary wing applications. The predictive tool will consider multiple physical scales, include random variance of material and strength properties due to fiber waviness, wrinkles and porosity/voids associated with manufacturing, fiber directions, type of fibers and resins, number of layers, stacking sequence, environmental conditions and type of loading such as impact and cyclic. This tool will perform virtual tests to interpolate and extrapolate real test data. Also, it will enable virtual experiments to examine at scales that would be expensive or impossible during actual experiments. Specifically, it will enable to match fiber architecture to complex load configurations to achieve optimal design. Furthermore, it will reduce the number of reduce certification tests by at least an order of magnitude by providing the best possible prediction of residual strength or remaining life based on limited data and probability of failure. Return