A global-local approach to describe the damage propagation in composite laminated structures

In the last years meaningful improvements have been made in understanding failure mechanisms of composite materials.Delamination and other damage mechanisms, such as matrix cracks, fibre-matrix debonding and fiber failure, can appear as a consequence of impact events with foreign objects, under service conditions and maintenance operations. These phenomena are seldom analyzed together without discussing how the interferences between the different damage mechanisms can influence their evolution under different loading conditions. In the present work, the activities will be focused on the development of a specific numerical procedure, able to describe the failure modes of composite structures subject to a low velocity impact. A very fine mesh refinement is required in the impacted area, where the impact induced damage will onset. In order to reduce the computational cost without compromises on the accuracy of results, a global/local approach has been adopted: a very refined mesh has been used in the critical region, whereas a coarser mesh has been used in the rest of the domain. In the present work Multi-Point-Constraints (MPS) has been used to link the local domain to the global domain without using transition meshes. The implementation and the analyses have been performed in the ABAQUS® FE code