Modeling and Simulation of Hybrid Materials/Structures for Sustainment Applications

ABSTRACT: A Hybrid Structure Evaluation and Fatigue Damage Assessment (HYSEFDA) toolkit for Abaqus will be developed for advanced hybrid structures under multi-axial and variable amplitude cyclic loading. The tool will be able to characterize arbitrary geometric configurations of fiber metal laminates with the coexistence of multiple metal ply and delamination cracks. High computational efficiency and modeling fidelity will be achieved via the development of a mesh independent discrete crack network model for co-simulation of a curvilinear fatigue crack growth in a metal ply and propagation of a delamination with its arbitrary front. A Moment Schema Finite Element coupled with XFEM will be developed to efficiently simulate the crack growth in a thin laminated structure. A mesh independent adaptive fracture process zone model will also be developed in HYSEFDA for accurate extraction of fracture parameters along the delamination crack front that is not in conformation to the existing FEM mesh. An advanced fatigue damage accumulation model coupled with a cycle-by-cycle numerical integration will be developed to capture the load sequence effects. GEM has secured commitments for technical support and commercialization assistance from Alcoa for module development, toolkit verification and validation at component and structural level. BENEFIT: The Phase II research will develop a versatile, user-friendly, and computationally efficient toolkit for Abaqus (HYSEFDA) that is capable of prediction of fracture pattern and fatigue life of non-traditional hybrid materials/structures under variable amplitude loading. The end product from this research will have significant benefits and commercial application in the Air Force, DoD Labs, and other commercial industries for optimal hybrid system design and performance of virtual testing of the selected hybrid material/structure system. The tool can be used by government agencies and private industries as follows: 1) to accelerate fatigue damage and residual strength 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.