Fracture Evaluation and Design Tool for Welded Aluminum Ship Structures Subjected to Impulsive Dynamic Loading

A software toolkit for Abaqus (XSHELL) will be developed for fracture evaluation and load deflection prediction of welded aluminum ship structures subjected to impulsive loading. The mesh independent crack description and fracture energy dissipation will be achieved in XSHELL through the implementation of two overlay elements with an embedded cohesive interaction along an arbitrary crack segment without in conformation to the existing finite element mesh. In addition to the implemented Belytschko-Tsay shell elements, new XFEM shell elements will be developed in their triangular and quadrilateral formats that better capture the kinematics of warped elements and curvature. Modified Mohr-Coulomb and a Johnson Cook models coupled with a nonlocal failure theory will be implemented to capture the nonlinear fracture initiation in aluminum alloys. A mixed mode cohesive and crack growth direction law will be used to drive the subsequent crack propagation and its associated energy dissipation. Global Engineering and Materials, Inc. (GEM) has commitments for technical support from Professor Jack Chessa at The University of Texas at El Paso, Professor Ted Belytschko from Northwestern University, and Professor Robert Dodds from University of Illinois at Urbana-Champaign. To help commercialize the XSHELL technology, GEM has also secured endorsement and support from Alcoa and NOV (National Oilwell Varco).