Modeling and Simulation of Hybrid Materials/Structures for Sustainment Applications

A software tool for residual strength and life prediction of advanced hybrid structures will be developed by enhancing and integrating an existing mesh independent 3D X-FEM solid element with a partially bonded cohesive interface element in Abaqus. The tool will be able to model arbitrary location, size of damage, and geometric configuration of fiber metal laminates with the coexistence of metal layer cracking and interface delamination. High computational efficiency and modeling fidelity is achieved via the level set description of crack geometry without remeshing, characterization of a curvilinear crack growth and the evolution of its nearby delamination zone without user intervention, and extraction of the crack growth driving force in the presence of its wake bridging. Global Engineering and Materials, Inc. (GEM) has secured strong commitments for technical support from Alcoa Technical Center, who will provide the use of their existing tool, supporting data, and expertise. In addition, Dr. Heinmann at Alcoa will provide GEM with his user experience and advice on desired functionalities of the final integrated Abaqus toolkit. The multi-faceted feasibility study consists of developing a method that will enable the prediction of multi-site, multi-mode damage initiation, propagation, and interaction in AHSs subjected to monotonic and fatigue loading. BENEFIT: The end product from this research will have significant benefits and commercial application in the Air Force, aerospace, DoD Labs, and commercial industries. It will result in: 1) a commercially viable, accurate, computationally efficient, and user-friendly residual strength and life assessment tool for tailoring and optimal design of advanced hybrid structures; and 2) a virtual testing tool to reduce current certification and qualification costs which are heavily driven by experimental testing under various design configurations and loading conditions. The tool can be used by government agencies and private industries as follows: 1) to accelerate residual strength and fatigue damage assessment, assist in decision making for effective maintenance and repairs, and design reliable AHSs to ensure airworthiness; 2) to specify fatigue performance limits and safety standards for structural certification and design agencies; and 3) to provide optimal designs through the effective use of new analysis tools, risk evaluation methods, and health management procedures for aircraft manufacturers.