Talks and presentations

Bayesian Calibration of Material Model Parameters for High-Velocity Impact Problems through Ensemble Kalman Inversion

July 23, 2025

Talk, 18th U.S. National Congress on Computational Mechanics, Chicago, Illinois, USA

In this work, we employ ensemble-based data assimilation (DA) to calibrate material model parameters under high-velocity impact conditions. DA integrates experimental observations with numerical models. By iteratively updating simulation inputs based on observational data, DA minimizes errors arising from both numerical approximations and experimental inaccuracies. Specifically, we use smoothed particle hydrodynamics (SPH) simulations as the dynamic system. The discrete-time nature of SPH simulations makes them particularly well-suited for sequential DA methods. We apply the ensemble Kalman filter (EnKF), a robust DA technique, to refine material model parameters by reconciling discrepancies between experimental observations and simulation results. This work signifies a substantial progression towards integrating DA techniques into high-strain-rate material modeling and demonstrates the potential of combining experimental data with advanced numerical methods to address challenges in high-velocity impact applications. The expected outcome is an improved methodology for calibrating material models and estimating model parameters, yielding more accurate and reliable high-velocity impact simulations.

Bayesian Calibration for High-Velocity Impact Problems through Ensemble-Based Data Assimilation

April 09, 2025

Talk, The 2025 Mach Conference, Annapolis, Maryland, USA

This presentation addressed the calibration challenges in high-velocity impact modeling by applying ensemble-based data assimilation (DA) to Smoothed Particle Hydrodynamics (SPH) simulations. Utilizing the ensemble Kalman filter (EnKF), we iteratively integrated experimental observations and simulation results to enhance accuracy of material model parameters. The resulting improved calibration framework significantly advances reliability and precision in high-strain-rate impact simulations.

Characterization of Energy Dissipation and Material Failure Mechanisms In High-Velocity Impact of Magnesium Alloys

November 17, 2024

Talk, ASME 2024 International Mechanical Engineering Congress and Exposition, Portland, Oregon, USA

This presentation investigated the mechanisms of material deformation, failure, and energy dissipation in high/hyper-velocity impacts on magnesium alloys impacted by steel projectiles (up to 3 km/s). A high-fidelity Smoothed Particle Hydrodynamics (SPH) model, calibrated with plasticity, fracture, and EOS models, was validated against experimental data. Parametric studies revealed critical insights into energy partitioning and failure mechanisms, guiding protective system design.

A Numerical Analysis of Energy Dissipation and Failure Mechanisms in Magnesium Alloys Subjected to High-Velocity Impact

November 01, 2024

Talk, Kentucky Academy of Science Annual Meeting, Frankfort, Kentucky, USA

The presentation performed a computational analysis of high-velocity impacts (1.2–2.4 km/s) between stainless steel projectiles and magnesium alloy targets using Smoothed Particle Hydrodynamics (SPH). Simulations reveal principal failure mechanisms, quantify energy dissipation into kinetic and internal energies, and demonstrate velocity-dependent energy partitioning. Results highlight peak kinetic energies at shock-wave arrival and evolving energy distributions during penetration.