The complex multi-scale failure modes, damage evolution, and fragmentation resulting from high velocity contact- impact processes in solids and structures pose considerable di culties in simulations using nite element methods. J. S. Chen is one of the original developers of meshfree methods for modeling material damage in fragment- impact processes. The in-house Nonlinear Meshfree Analysis Program (NMAP) developed by Chen’s group has been successfully applied to the modeling of Behind Armor Debris as shown in the gure below, simulated using the newly developed stabilized nodal integration and natural kernel contact algorithm. The simulation results have been validated by the Army Engineer Research & Development Center (ERDC). NMAP has also been applied to landslide modeling as shown in the left bottom gure where the shearband localization and damage processes were properly captured by the proposed micro-crack informed damage model and implicit gradient regularization method.