Triaxial tests on snow at low strain rate. Part I. Experimental device
Triaxial tests on snow at low strain rate. Part I. Experimental device
复制标题
低应变率下的雪三轴试验。
作者：
M. Moos;P. Bartelt;A. Zweidler;E. Bleiker
摘要为了研究高山雪的力学特性，研制了一种变形控制三轴仪。圆柱形试样（直径58 mm，高126 mm）可以通过施加2.4 × 10−7 s−1和2.4 × 10−2 s−1之间的拉伸或压缩应变速率进行轴向变形。压缩空气被用来横向加载的雪标本的压力高达40千帕。体积变形被发现通过仔细封装在一个密封的聚酯薄膜箔的雪样品和测量样品变形过程中排出的孔隙空气。因此，多维应力-应变行为可以确定，本构理论的雪先进。该设备位于瑞士联邦雪与雪崩研究所Weissfluhjoch研究站的冷藏室中。在过去的四个冬天里，已经进行了大约180次测试。雪样本的密度在190至435 kg m-3之间变化。这两部分论文的第一部分讨论了仪器的发展和应用的测试方法。提供了定性结果。在第二部分中，详细分析的结果和量化的雪的粘弹性。
Abstract A deformation-controlled triaxial apparatus has been developed in order to investigate the mechanical behaviour of alpine snow. Cylindrical specimens (58 mm in diameter, 126 mm in height) can be axially deformed by applying tensile or compressive strain rates between 2.4 × 10−7 s−1 and 2.4 × 10−2 s−1. Compressed air is used to laterally load the snow specimens with pressures of up to 40 k Pa.The volumetric deformation is found by carefully encapsulating the snow samples in an airtight Mylar foil and measuring the expelled pore air during sample deformation. The multidimensional stress–strain behaviour can therefore be determined, and constitutive theories of snow advanced. The device is located in the cold rooms of the Weissfluhjoch research station of the Swiss Federal Institute for Snow and Avalanche Research. Some 180 tests have been performed over the last four winters. The density of the snow specimens varied between 190 and 435 kg m−3. Part I of this two-part paper discusses the development of the apparatus and the applied testing methodology. Qualitative results are provided. In Part II, a detailed analysis of the results is presented and the viscoelastic properties of snow quantified.