Impact and friction mechanisms and structural changes of snow and ice in snow avalanches, ice blasts and icy planetecimal impacts

冰-冰摩擦力的测量被扩展到最低的滑动速度，最初在该项目中的目标。为了进行实验，我们建造了一个新的非旋转型装置，并将其安装在冷室中，这使得我们能够在10 <-7>~ 10 μ <-3>m/s的速度和123 ~ 368 kPa的法向应力下进行摩擦实验。在10 μ m/s以下得到的结果<-4>与传统的粘附剪切机理所预期的结果不同。在此基础上，提出了一种新的考虑了滑动面上冰微凸体烧结结生长的粘附剪切机制模型，并对小行星、火星和其它冰体上风化层特征坑的形成机制进行了高速撞击实验研究。所用样品为H_2O冰、CO_2冰和岩石的混合物，弹丸由H_2O冰、金属或塑料制成，撞击速度为100 ~ 600 m/s。该项目是与华沙大学Leliwa-Kopystysnski教授合作进行的。研究了电场对冰摩擦力的影响。

Ice-ice friction measurements were extended to the lowest sliding velocities aimed originally in the project. For the experiment a new device of non-rotation type was constructed and installed in a cold room, which enabled us to carry out the friction experiment to the velocities of 10^<-7> to 10^<-3> m/s and normal stresses of 123 to 368 kPa. The obtained results below 10^<-4> m/s was different f rom what has been expected from the traditional adhesion shear mechanism. Based on the experiment al result a new model of adhesion shear mechanism was proposed taking account of junction growth d ue to sintering of ice asperities on the sliding surfaces.High speed impact experiments were conducted in relation to the formation mechanism of characteristic craters found on regolith layers on asteroids, Mars, and other icy bodies. Samples used are mixtures of H_2O ice, CO_2 ice and rocks, and projectiles, made of H_2O ice, metal or plastic, were impacted with a speed of 100 to 600 m/s. The project was conducted with cooperation of Prof. Leliwa-Kopystysnski of Warsaw University. Effects of electric field on ice friction were investigated.