【摘要】 爆炸冲击荷载作用下温度和应变率对钢材动态力学性能的影响一直备受关注。Fe-C合金体系是钢材的基本组成部分;以Fe-C合金为基本研究对象,采用分子动力学方法模拟九种温度和四种应变率条件下Fe-C合金的单轴动态拉伸过程。结果表明:在所研究的温度和应变率范围内,Fe-C合金弹性模量对于应变率变化不敏感,对于温度变化非常敏感;随着温度的升高,弹性模量明显减小;相同温度条件下,屈服强度和峰值应变随应变率的增大而增大;相同应变率条件下,屈服强度和峰值应变随温度的升高而减小;温度和应变率对屈服强度的影响不具有相关性。基于分子动力学模拟,建立的纳米尺度下Fe-C合金动态拉伸力学性能计算公式能反映温度和应变率效应的共同影响,为钢材在爆炸冲击作用下动态拉伸力学性能描述提供依据。更多还原

【Abstract】 Dynamic mechanical properties of steel under the loading of blast and impact is always a concerned issue. Regarding Fe-C alloy,the basic composition of steel,as the research object,the uniaxial tensile deformation of Fe-C alloy at nine temperatures and four strain rates was analyzed using molecular dynamics( MD) simulations.In the research range,it was shown that the elastic modulus of Fe-C alloy is independent on strain rate,but sensitive to temperature,the elastic modulus decreases obviously with the increase of temperature; the yield strength and peak strain increase with the increase of the strain rate at the same temperature; the yield strength and peak strain decrease with the increase of temperature at the same strain rate; there is no interrelation between the temperature and strain rate effects of the yield strength. To provide evidence for the description of dynamic tensile mechanical properties of steel under the loading of blast and impact,the forecasting formula on dynamic tensile mechanical properties of Fe-C alloy affected by temperature and strain rate at nanometer scale was put forward based on the results of the simulation.更多还原