不同波形加载下[100]单晶铝层裂破坏的分子动力学模拟研究OA北大核心CSTPCD

In this study,molecular dynamics method was used to simulate the deformation and spallation behavior of[100]single crystal aluminum under the action of equivalent ramp waves and square waves.Accordingly,the correlation between loading waveform and spallation behavior was analyzed.The results showed that the synergistic effect of the pulse shape transition and the thermodynamic path affected the material spallation.The nucleation of non-uniform holes dominated by defects was not the decisive factor affecting the spallation strength of materials.The difference of spallation characteristics of materials under different loading waveforms was mainly determined by the difference of temperature rise under different thermodynamic paths,which led to uniform spallation at maximum velocity of 3.00 km/s,but the spall strength of ramp wave group was 56.6％higher than that of square wave group.Due to the gradual compression and slight temperature softening effect,the ramp wave loading made the material presented milder damage than the impact loading,which became more significant with the increase of loading speed.