Innovative Approaches for Improving Progressive Damage Modeling and Structural Life Prediction of Airframes

An automatic software tool for 3D fatigue crack growth prognosis of structural systems under realistic complex loading will be developed by integrating a unified growth model with a mesh independent extended finite element toolkit in ABAQUS. The tool will be able to model arbitrary non-planer crack growth over multiple growth regimes with an arbitrary stress ratio without user intervention or remeshing. GEM has established the business partnership with SIMULIA (ABAQUS) and secured commitments for technical support from Bell Helicopter, who will provide supporting data, information, and expertise. In addition, our consultant, Professor Liu from Clarkson University, will aid in fatigue model development, and provide existing fatigue damage model for the toolkit integration. The multi-faceted feasibility study consists of developing an add-on ABAQUS toolkit that will enable the following: 1) a new unified fatigue crack growth modeling technique that captures the stress ratio effects under both uniaxial and multiaxial load; 2) arbitrary insertion of multiple 3D cracks that are independent of the finite element mesh; 3) characterization of a growing crack using the level set and fast marching method; and 4) demonstration of the applicability and computational efficiency of the developed toolkit at component and structural level.