Professor J. S. Chen and his students are working with the U.S. Army Engineer Research and Development Center to develop a micro-crack informed damage model and multiscale reproducing kernel particle method (RKPM) formulation to model impact and penetration into brittle materials. By developing a semi-Lagrangian stabilized nodal integration formulation, key phenomena such as multi-body contact, material fragmentation, and large material flow are accurately modeled. The multiscale formulation provides a critical link between microstructure failure and macroscale damage (Fig. 1), leading to improved modeling of material softening and failure, which is crucial in penetration events (Fig. 2). Similar numerical techniques have also been applied to metal forming and earth-moving simulations that are difficult to be modeled by the mesh based finite element methods.
Figure 1. Micro-crack informed damage model
Figure 2. Meshfree multiscale modeling of bullet penetration through concrete walls