Development of Fatigue Life Prediction of Rotor Spars by Using Discrete Damage Modeling

This notice is provided for information purposes only. NASA Langley Research Center (LaRC) awarded a firm-fixed price contract to the University of Texas at Arlington, for the effort entitled "Development of Fatigue Life Prediction of Rotor Spars by Using Discrete Damage Modeling". This award results from a competitive selection under the NASA Headquarters released NASA Research Announcement (NRA) NNH15ZEA001N for foundational research in support of the Aeronautics Research Mission Directorate (ARMD), entitled "Research Opportunities in Aeronautics (ROA) 2015", Appendix A.5 Advanced Composites Project (ACP1), Subtopic 5.2.1.3 Fatigue Life Prediction of Rotor Spars via Progressive Damage Analysis.

NASA's Advanced Composites Project, as a part of the ARMD Advanced Air Vehicles Program, is seeking to reduce the timeline for development and certification of state-of-the-art composite materials and structures, which will help make advanced composite components more competitive in the commercial aircraft market. ACP will accomplish this goal by infusing leading-edge, physics-based tools to improve composite structures characterization and simulations, develop standardized procedures, and optimize fabrication processes to enable the reduction of the existing 10 year development and certification timeline for aircraft structures by 30%.

This effort will extend the Discrete Damage Modeling (DDM) framework to predict damage modes and fatigue life of composites. DDM represents an approach to progressive failure modeling in composites when multiple individual damage events, such as matrix cracks and delamination, are explicitly introduced into the model via the displacement discontinuities which they create. The proposed effort will utilize a Regularized extended Finite Element (Rx-FEM) technique, which is a part of a broader analysis software known as B-Spline Analysis Method (BSAM), and will be enhanced to predict damage modes due to cyclic loading and fatigue life. The BSAM software will then be incorporated in a commercial finite element code that would allow U.S. industry to utilize these improvements.