多孔铁冲击温度的分子动力学模拟

Shock Temperatures of Porous Iron from MD Simulations

采用Matsui和Anderson提出的Morse型有效原子对势及导带电子热激发能贡献 ,通过分子动力学方法 (MD)对多孔铁的冲击温度进行了数值模拟。计算时 ,采用了在一定冲击压力下多孔铁样品已转变为均匀介质的近似。多孔铁冲击温度的模拟结果与经合理修正后的热力学计算结果相一致。这个结果表明 :在一定的冲击压力下 ,多孔材料样品确实存在一个热力学平衡状态下的温度值。以上结论可能也适用于更高孔隙率的样品 ,当然这一观点还需要更多的实验结果给予证实。

According to the assumption that porous iron sample has transformed to homogeneous medium under a given shock pressure, a Morse-type potential is used to simulate Hugoniot curve and shock temperatures of porous iron by MD method. The Morse potential has three adjustable parameters, which are determined from experimental data of iron's thermo-elastic properties by Matsui and Anderson. The simulation results are in good agreement with thermodynamic data for porous iron with a porosity of 12.1%, which implies that porous sample of a given porosity has a thermodynamic equilibrium temperature under a given shock pressure. However, whether the conclusion could be applicable to porous samples with large porosities needs to be further verified by experiments.