MD Simulation Data for Shock-Induced Spall in Aluminum Bicrystals Containing Symmetric Tilt and Twist Grain Boundaries

This contains molecular dynamics (MD) simulation data used to investigate shock-induced spall and dynamic failure in aluminum (Al) bicrystals containing symmetric tilt (STGB) and symmetric twist (STwGB) grain boundaries (GBs). The simulations were conducted to examine how GB character and misorientation influence the spall response under high strain-rate loading.

Ten bicrystal configurations, covering low to high misorientation angles, were modeled using a flyer-target setup at impact velocities between 1.0 and 3.5 km/s. The simulations were performed with the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) using the embedded-atom method (EAM) potential for Al. Periodic boundaries were applied laterally, while free surfaces were maintained along the shock direction. The shock propagation, free-surface velocity (FSV) profiles, and atomic-scale mechanisms were analyzed to extract spall-fracture parameters.

The dataset includes: (i) LAMMPS input scripts and parameter files for all simulations, (ii) Atomic configuration files representing initial bicrystal models for STGBs and STwGBs, (iii) Output files containing time-resolved FSV profiles, pressure histories, and thermodynamic data, (iv) Processed data used to determine spall strength and strain-rate dependence, (iv) Post-processing scripts (GnuPlot/Fortran) used for analysis of wave profiles and spall strength fitting.

The data support the study titled “Strain Rate Effects on Shock-Induced Fracture in Symmetric Grain Boundaries of Aluminum: Insights from Molecular Dynamics”. The results highlight that spall strength depends strongly on GB character and deviates from macroscopic experimental trends, revealing orientation sensitivity at atomic scales.

Average spall strengths were found to be 10.3 ± 0.9 GPa for STGBs and 9.35 ± 3.15 GPa for STwGBs, with higher scatter observed for twist boundaries. The variations stem from strain-rate sensitivity, elastic–plastic transitions, and defect activity.

This dataset can be used to reproduce simulations, compare spall behavior across GB types, or develop validation benchmarks for atomistic models of shock-induced fracture in metals. It provides a valuable resource for understanding GB-mediated spall processes and for designing materials with tailored dynamic response.