High-Fidelity Residual Strength and Life Prediction Tool for Adhesively Bonded Composite Structures

Global Engineering and Materials, Inc. (GEM) along with its team members (National Institute for Aviation Research (NIAR) at Wichita State University, Carnegie Mellon University, and Air Force Research Lab (AFRL)) will develop an add-on toolkit for Abaqus with high fidelity prediction of residual strength and life of bonded composite structures. A coupled continuum and discrete damage analysis will be developed for Abaqus to capture the entire failure sequence under monotonic and fatigue loading. To accurately capture the effect of fabrication induced initial defect and the mechanism driven bondline failure, a novel macro-micro bridging model will be developed to determine the cohesive model parameters. A unified cohesive interaction for crack initiation and propagation will be developed for the macro-level fatigue damage prediction with a local strain based delamination initiation criterion. The validated static and fatigue analysis toolkit will then be enhanced during the 2nd year program through its integration with a thermal and moisture diffusion model to study the environmental aging on the residual strength and life of a bonded composite structure. An integrated CAD and FEM demonstration and a validation study of the developed toolkit will be performed using the test data from NAVAIR, NIAR and AFRL.