论文标题
在高压坡道上的状态和强度方程
Equation of state and strength of diamond in high pressure ramp loading
论文作者
论文摘要
钻石被广泛用作高能密度实验的组成部分，但现有状态（EOS）模型的现有方程并未捕获其对动态载荷的响应。特别是，与第一原理理论EOS模型相反，未检测到固体相变的变化，并且没有通用的EOS模型与测量的环境等温线匹配。我们已经对钻石相进行了密度功能理论（DFT）计算，远远超出了其热力学稳定性范围，并将这些结果用作Mie-Greuneisen EOS的基础。我们还对弹性模量进行了DFT计算，并校准了用于模拟的代数弹性模型。然后，我们通过与在坡道加载实验中测得的应力密度关系进行比较来估计钻石的流动应力。所得的本构模型使我们能够对泰勒 - Quinney因子（转换为热量的塑料工作的比例）对钻石不会在坡道压缩上融化的观察结果。
Diamond is used extensively as a component in high energy density experiments, but existing equation of state (EOS) models do not capture its observed response to dynamic loading. In particular, in contrast with first principles theoretical EOS models, no solid-solid phase changes have been detected, and no general-purpose EOS models match the measured ambient isotherm. We have performed density functional theory (DFT) calculations of the diamond phase to ~10TPa, well beyond its predicted range of thermodynamic stability, and used these results as the basis of a Mie-Greuneisen EOS. We also performed DFT calculations of the elastic moduli, and calibrated an algebraic elasticity model for use in simulations. We then estimated the flow stress of diamond by comparison with the stress-density relation measured experimentally in ramp-loading experiments. The resulting constitutive model allows us to place a constraint on the Taylor-Quinney factor (the fraction of plastic work converted to heat) from the observation that diamond does not melt on ramp compression.
