冰球冲击试验的近场动力学方法数值模拟

为了研究近场动力学方法在模拟冰体高应变率破坏行为的可靠性,基于近场动力学理论通过自编程实现对冰球高速冲击力学行为的数值模拟,将计算结果和试验结果进行对比。结果发现:近场动力学方法能准确模拟冰球冲击过程下高应变率破坏的完整过程,对球体表面裂纹扩散以及冰球整体裂解的细节模拟十分到位,且在20~60 m/s速度范围内对冲击载荷预报的幅值最大误差18.2%,均值最大误差18.4%;同时,发现在20~60 ms/中低速冲击过程中,冰球破坏以半球切面为界限,靠近冲击面的下半球体呈粉碎性破坏,上半球体呈碎片状破坏,当冲击速度大于60 m/s后,继续增大速度会使上半球体破坏程度剧烈增大;当冲击速度大于100 m/s,上下半球都呈粉碎状破坏。

Numerical simulation of ice sphere impact test by peridynamics method

In order to study the reliability of peridynamics method in simulating the failure behavior of ice at high strain rate, the numerical simulation of high-speed impact mechanical behavior of ice sphere was realized by self-programming based on the theory of peridynamics, and the calculated results were compared with the experimental results. The results show that the peridynamics method can accurately simulate the complete process of high strain rate failure during the impact process of the ice sphere, and the details of the surface crack diffusion of the sphere and the overall cracking of the ice sphere are well simulated, and the maximum amplitude error of the impact load prediction within the velocity range of 20-60 m/s is 18.2%, and the maximum mean error is 18.4%. At the same time, it is found that in the process of medium and low speed impact of 20-60 m/s, the destruction of the ice sphere takes the hemispheric section as the boundary, the lower hemisphere near the impact surface is crushed, and the upper hemisphere is fragmented, when the impact velocity is greater than 60 m/s, the damage degree of the upper hemisphere will increase sharply as the impact velocity increse; when the impact speed is greater than 100m, both the upper and lower hemispheres are crushed.