结合高压热弹性模拟数据的Hugoniot弹性极限实验解读OA

The Hugoniot elastic limit(HEL)serves as the critical stress threshold demarcating the transition from purely elastic to elastoplastic response under dynamic loading.Accurate determination of the HEL is essential for understanding dynamic mechanical behavior.Traditionally,the HEL is derived from the"double-wave"structure of free-surface velocity profiles.However,wavefront dispersion of the elastic precursor and non-steady-state effects in short-pulse laser-driven experiments introduce systematic deviations in longitudinal sound velocity measurements,thereby limiting precise HEL determination.To address these challenges,a self-consistent interpretation method integrating macroscopic conservation laws with microscopic thermoelastic simulations is established. Based on momentum conservation,this work establishes a self-consistent equation that relates axial stress to longitudinal sound velocity and particle velocity.This equation corresponds to the process in which high-stress perturbations catch up with low-stress wavefronts.Using the experimentally measured elastic-precursor particle velocity as the constraint,the HEL and the corresponding longitudinal sound velocity can be determined self-consistently by iteratively solving this equation,without relying on ambiguous wavefront arrival-time measurements.To support this procedure,a continuous sound velocity-pressure constitutive relationship is derived from a high-pressure thermoelastic dataset spanning 0-1000 GPa,constructed using density functional theory combined with the mean-field potential(MFP)method and the quasi-static approximation(QSA). The validity of this approach is verified using diamond as a benchmark material.The predicted elastic moduli agree with static compression data within 0.4％relative deviation up to 15 GPa.For gas-gun experiments with peak stresses reaching 1 TPa,the reinterpreted HEL values show less than 2％relative deviation from standard experimental benchmarks.These results quantitatively characterize the crystalline anisotropy,where the longitudinal sound velocity follows the sequence[111]＞[110]＞[100].For laser-driven experiments where non-steady-state attenuation previously caused systematic underestimation,the HEL values are corrected upward by 8％-13％,reconciling discrepancies between different loading platforms. This hybrid approach enables the retrospective correction of non-ideal experimental effects through solely through data reanalysis,thereby providing high-precision dynamic constitutive parameters under extreme conditions without requiring specialized experimental configurations.The datasets presented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00213.00274.