Polymer Design for Impact Induced Shock-Wave Mitigation
 | Polyurea has been shown to possess good dissipative properties and thus has been used as a shock-resistant material, especially to prevent the traumatic brain injury (TBI) resulting from impacts and blasts. Our research is focusing on to understand how this superior energy redirection and dissipation process achieved by the polyurea-like elastomers using atomistic-level simulations. The role of multiblock architecture of polyurea on the microstructure, viscoleastic properties, and shock response is investigated by using coarse-grained models. This study is important for the design of next-generation elastomeric materials for blast mitigation and also presents first detailed computational investigation of the viscoelastic and shock response of block copolymers.
|
Dynamic Response of Phenolic Resin and Its Carbon-Nanotube Composites to Shock Wave Loadings
 | Polymer-based composites have long been investigated for wide range of engineering applications including high strain rate loading (shock wave). However deformation and phase change mechanisms upon shock loading is still not clearly understood due to complexity of polymer materials. Additionally using direct MD shock simulations of polymers and its composites are rare. As a first attempt on direct MD simulations of shock response of polymers and polymer composites, we have chosen phenolic resin and its carbon-nanotube (CNT) composite. Shock loading are applied to CNT-resin composites parallel or perpendicular to the CNT axis and the anisotropy in wave propagation is examined. |
Plasticity in Cu/CuZr Glass Nanolaminates Under Uniaxial Compression
Large-scale (~ 3 mil atoms) molecular dynamics simulation is performed to investigate the plasticity in Cu/Cu46Zr54 glass nanolaminates under uniaxial compression. It is observed that the shear band is oriented at angles dictated by the crystallography of the crystal phase of Cu unlike pure glass whose dominant shear band is oriented at 45 degrees with the loading direction. Shear banding in the glass layer of the nanolaminates is induced by dislocations formed in the Cu layer. |  |
Dynamic response of Cu46Zr54 metallic glass to high-strain-rate shock loading: Plasticity, spall, and atomic-level structures
 | Metallic glasses are a subject of enormous experimental and theoretical efforts due to their superior mechanical and deformation mechanisms. My research is interested in dynamic properties of metallic glasses under shock loadings using MD. Cu46Zr54 is chosen as the model and Hugoniot shock states, shock-induced plasticity and spallation analysis are performed. Short-range structure and shear deformation features are characterized by Voronoi tesselation and von Mises shear strain analysis. Void nucleation and growth under various shock loadings are also investigated. |
9500 Gilman Drive, |
