The document describes Ge Wang's research using Hybrid Lattice Particle Modeling (HLPM) to simulate dynamic material behavior at the microscale. HLPM uses discrete particles to represent microstructural features and allow simulations of material failure from impacts, fractures and other high strain rate loads. Wang has published several journal articles applying HLPM to study crack propagation, wave propagation, material indentation and other dynamic phenomena.

1. Hybrid Lattice Particle Modeling (HLPM) of Dynamic Fragmentation of Solids Investigator: Ge Wang (gewang0419@gmail.com) Motivations Mechanical behavior of a solid material is controlled by its microstructure. Complex macroscopic behaviors, such as fracture and failure, arise from microstructure interactions. Thus, if the microstructure and the microstructural interactions within a numerical model could be correctly and accurately replicated, then that model should precisely reproduce the macroscopic behaviors. However, current computing power limits the size of the atomic ensemble to numbers of atoms that are too small to be useful for most engineering-scale systems. Hybrid Lattice Particle Modeling (HLPM) is developed to directly mimic microstructural features and can be executed in reasonable times on standard computers. Model Introduction HLPM is a dynamic simulation that uses small discrete solid physical particle (or quasi-molecular particles) as a representation of a given fluid or solid. Different particle interaction schemes and mesh structures can be adopted. Interactions of HLPM Linear Non-linear: (a) Polynomial (b) Lennard–Jones Validations of HLPM (a) Epoxy in tension Meshing structures Applications of HLPM High strain rate loading: Thermally induced fracture: (a) Temperature (b) Fracture Mixture of calcite and pyrite subject to a microwave Blasting: Crack propagation: Spallation of plate impact: Wave propagation: 3-D puncture and shock fracture: Acknowledgement NSERC, COREM (Canada), SERRI, ONR (USA) Material subject to heating: Random meshing (b) Indentation of polymeric materials Load Energy

2. Ge Wang’s other computational materials science related research work (gewang0419@gmail.com) Projectile penetration of material Helmet impact Bird impact on airplane wing Explosive in urban area

4. Ge Wang’s CFD and FSI related research work ( gewang0419@gmail.com) Atmospheric flow over a regional complex terrain and plume dispersion A 3D time-dependent mesoscale meteorological model, HOTMAC (Higher Order Turbulence Model for Atmospheric Circulations), is applied to study the complex terrain airshed. The outputs from HOTMAC are used as inputs for the ‘puff dispersion’ model, RAPTAD (Random Particle Transport And Diffusion), to capture details of the pollutant motions. Oscillatory flow Cavitating flow 2D shallow water equations are employed. Acknowledgement SERRI, SCERP, US Navy Velocity vectors Spatial plume trajectory A single fluid model of density-based sheet/cloud cavitation scheme is developed and incorporated into a weakly-compressible 3D FVM LES Navier-Stokes equations. Sheet cavitation Cloud cavitation 2D FEM-FDM LES technique is developed. Terrain Flood inundation due to dam and levee breach Prediction Scoring and erosion of the foundation soils Fluid-structure interaction Material erosion due to cavitating flow