High strain-rate interfacial behavior of layered metallic composites

• New predictive framework for dynamic interfacial delamination relations of aluminum composite.
• A new fracture methodology that can be used to model dynamic crack nucleation and growth.
• Effects of precipitates, dispersed particles, and GB interfaces accounted in dynamic fracture.

The high strain-rate interfacial behavior of layered aluminum composite has been investigated. A dislocation-density based crystalline plasticity formulation, specialized finite-element techniques, rational crystallographic orientation relations, and a new fracture methodology for large scale plasticity been used. Two alloy layers, a high strength alloy, aluminum 2195, and an aluminum alloy 2139, with high toughness, were modeled with representative microstructures that included precipitates, dispersed particles, and different grain boundary (GB) distributions. The new fracture methodology, based on an overlapping element method and phantom nodes, along with a fracture criteria specialized for fracture on different cleavage planes is used to model interfacial delamination. Dislocation-density evolution significantly affects the delamination process, and this has a directly related to the strengthening, toughening, and failure of the layered composite. It is also shown that brittle alumina (Al2O3) platelets in the interface region played an important role in interfacial delamination and overall composite behavior.