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CNA Seminar/Colloquium/Joint Pitt-CNA Colloquium

Bo Li
Case Western Reserve University
Title: Predictive modeling and simulation of High Energy Density (HED) dynamic response of materials

Abstract: Numerical modeling of the dynamic response and failure of materials under extreme conditions (extremely high pressure, high temperature and strain rates) is a long-standing challenge in computational mechanics. It places exact demands on numerical solvers, physics-based material models and high performance computing. We present here a novel computational approach, the Optimal Transportation Meshfree (OTM) method, to address these challenges. The OTM method based on a combination of Optimal Transportation theory, material point sampling and Local Maximum Entropy interpolation, provides a robust and efficient solution for general fluid and solid dynamic flows, possibly involving multiple phases, viscosity and general equations of state, general inelastic and history dependent constitutive relations, arbitrary variable domains and boundary conditions. A variational material point failure algorithm (Eigenerosion) within the OTM framework is developed to predict the fracture and fragmentation in materials under extreme conditions. We take the conventional verification and validation (V&V) analysis to evaluate the performance of our approaches as well as model-based UQ analysis to determine the error and uncertainties of our models in the applications of terminal ballistics and hypervelocity impacts. The range and scope of the method is also demonstrated in our monolithic Lagrangian Fluid-Structure-Interaction (FSI) simulations. The second part of this presentation will focus on the multiscale modeling of materials strength and failure in extreme dynamic environment. A variational thermomechanical concurrent multiscale computational framework will be introduced that allows for direct numerical simulation of the polycrystalline structure coupled with void growth, single crystal plasticity, phase transformation, physics-based hardening and rate sensitivity laws, and First principles calculations of the Equation of State and material properties. Due to the complexity nature of these computations, I will also touch upon the development of the massively parallel implementation of the Optimal Transportation Meshfree (pOTM) method to take advantage of high performance computing systems.

Date: Tuesday, April 1, 2014
Time: 1:30 pm
Location: Wean Hall 7218
Submitted by:  David Kinderlehrer