高应变率下纯水冰和杂质冰的动态力学行为

Dynamic compression property of distill-water ice and impurity-water ice at high strain rates

通过采用大热惯性试件快速加载技术和波形整形技术,对3种冰材料在-18℃下的动态压缩性能进行测试,实验中试件达到了应力均衡和近似恒应变率加载等条件。通过实验波形对比分析,解释了反射波和透射波中的“双峰现象”。在700~2 700 s^-1的应变率范围内,纯冰试件的压缩强度为14.5~49.3 MPa,相比于准静态结果表现出明显的动态增强效应。含有杂质的冰试件总体峰值应力相比于纯水冰试件有较大提升,而峰值应力对应的平均应变在减小,这表明添加了杂质的冰试件动态模量增大,冰材料变得更硬,其抵抗变形的能力更强。b型试件所表现出的强度(41.3~51.6 MPa)较a、c型试件均有提高并且分散性较小,说明该试件中杂质与冰晶体之间的结合力较强,抑制了微裂纹的萌生、扩展、成核等过程。

The dynamic strength of three kinds of ice specimens at -18 ℃ were tested by the split Hopkinson pressure bar (SHPB) method. The pulse-shaping technology was used to achieve constant strain rate loading and stress equalization. The double-peak phenomena of reflection wave and transmission wave were explained by comparing with stress waveforms. The compression stress of distill-water ice in the strain rate range from 700 to 2 700 s^-1 is 14.5-49.3 MPa, and it is much higher than the static data. Generally, the dynamic compression stress of the impurity-water ice is higher than that of the distill-water ice, this indicate that the ice specimens become harder after adding impurities, and the capability to resist deformation is enhanced. Compared with a-type and c-type specimens, the crack stress of b-type specimens becomes higher and its dispersiveness is lower. This indicates that the adhesive forces between impurities and ice crystals become stronger, and the expending and nucleate process of cracks is restrained.