GEM has expertise in several research areas of engineering importance.
Advanced Materials & Structures
GEM’s Structure Engineering and Failure Analysis Group has expertise and ample experience in performing virtual testing, response and failure prediction, and design support for advanced materials and structures. GEM has developed a structure integrity and durability analysis model for a composite wing box with multiple delamination cracks between the skin and stiffeners. A cohesive zone model is used to simulate the growth of multiple delamination cracks under static and fatigue loading. The growth and coalescence of these multiple delamination cracks have been observed under both the monotonic and fatigue loading.
Under the sponsorship of the Office of Naval Research (ONR), GEM’s Structural Engineering and Failure Analysis Group has developed a dynamic response model for a representative ship hull subjected to extreme loading. A fluid-structure interaction model has been developed by embedding the ship hull in its surrounding fluid. A suite of user-defined material models has been developed and combined with Abaqus’ existing models to capture the rate dependent material behavior, material softening, and debonding and delamination. A compared analysis has been performed for both a conventional steel hull and its equivalent hybrid hull consisting of a steel frame bonded with sandwich composite panels.
To quantify the local failure mechanism associated with a dynamic event, a refined local analysis model is developed and embedded into the global hull model via Abaqus’ submodeling technique. The developed analysis toolkit along with the coupling technique is applied to evaluate the dynamic response and failure progression in a representative hybrid and its equivalent steel hull.