再入气动环境类电池帆板材料微观响应变形行为分子动力学模拟研究

Molecular Dynamic Simulation of Microscopic Response Deform Behaviors of Battery-like Sailboard Material Under Re-entry Aerothermodynamic Environment

针对服役期满大型航天器无控飞行轨道衰降再入大气层解体过程及落区难以提前预测,再入解体后生成的碎片可能造成地面危害等问题,采用分子动力学模拟方法,选取MEAM势函数,构建了碳元素质量分数0.215%的含碳钢分子动力学模型,计算了不同温度下材料的平衡态晶格常数,并通过晶格常数与温度的关系,计算了模型的线膨胀系数,验证了MEAM势函数在所建立的仿真模拟系统合理性;使用经过验证的分子动力学模型与MEAM势函数,模拟了钢制平板在Ma∞=8.37,Kn∞=0.01,γ=1.4的高超声速再入气动环境中,通过结构动态热力响应变形行为有限元算法计算出的部分状态下材料微观演化行为,初步证明了分子动力学模拟方法在服役期满大型航天器再入大气层解体过程的分析仿真计算中的作用,为实现分子动力学方法同动态热力响应有限元算法的耦合奠定了基础。

It is difficult to predict the disintegration process and the reentry point of the large uncontrolled space vehicle after retirement,while the debris generated from reentry disintegration may cause ground damages.To solve this problem,the lattice constants of steel with 0.215%carbon content at different temperatures were calculated using the molecular dynamics simulation method on the basis of the choice of the MEAM potential.By analyzing the correlation of lattice constant with temperature,the linear expansion coefficient was calculated and the rationality of the model and the MEAM potential function was verified.For a steel plate in hypersonic re-entry environment(Ma∞=8.37,Kn∞=0.01,γ=1.4),the microscopic behaviors of the material under some states were calculated by thermodynamic coupling response of the structure.By applying the molecular dynamic simulation method in the analysis of the spacecraft re-entry process,the role of MD was proved.It lays a foundation for the coupling of the present molecular dynamic with the finite element algorithm for dynamic thermal response of structure.