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

A hybrid damage initiation and propagation toolkit for Abaqus will be developed for residual strength and life prediction of adhesively bonded composite structures. This tool will for the first time be able to simulate concurrently both the continuum and discrete damage based progressive failure within the mesh independent computational framework for the solution domain away and near the bondline, respectively. To capture the highly nonlinear material response and the process and environment driven mechanical properties along the bondline, the adhesive layer will be characterized explicitly without introducing a smearing procedure. Given the thin thickness of both the adhesive layer and individual plies above and below the bondline, a continuum shell element along with its phantom pair will be developed to capture the discrete matrix cracking without remeshing. An adaptive fracture process zone model will be developed for an accurate extraction of fracture parameters along the moving crack front within individual plies and at their interface. A unified damage initiation and propagation model will be implemented for both the composite laminate and adhesive to perform the total life prediction under the thermal/mechanical/environmental loading. GEM has secured commitments for technical support from LM, Sikorsky, and Air Force Research Lab.