The High Fidelity Building Block and Validation Protocols for NextGen Composite Methods Program (N00014-21-C-1008) seeks to provide industry with the critical experimental data and supporting guidelines by which to evaluate, validate, and demonstrate the predictive capabilities of advanced computational analysis tools. Following from the successful development of a coupon level database (N00014-14-C-0128), the HiFi NextGen program focuses on the subelement and element levels of the design-test-certification building block wherein the greatest expense for design substantiation is incurred. Additionally, data is developed to provide improved understanding of fundamental material behavior for composite material models. Advanced inspection techniques such as digital image correlation and in-situ micro computed tomography are used to capture damage onset, damage propagation, and ultimate failure within representative composite structure test specimens. Where applicable, the test program includes relevant environmental conditions. Validation guidelines focus on the use of emerging progressive damage and failure analysis (PDFA) computational techniques and address modeling considerations such as length scale, material models, numeric implementation, mesh objectivity, modeling strategy, and computational scalability. All test articles are fabricated from IM7/5320-1 tape and fabric as well as FM309-1 structural adhesive to maintain a high degree of relevancy for future aircraft needs.
Techniques for Modelling and Optimizing the Mechanical Properties of Natural Fiber Composites: A Review
