Mechanical properties of snow using indentation tests: size effects

Abstract

ABSTRACT. An attempt is made to obtain and quantify the mechanical properties of two common types of seasonal snow on the ground. Different samples of natural snow whose metamorphism had stabilized (such as would remain on a road throughout winter in a cold, snowy area) were gathered and tested using mesoscale indentation tests (metrics on the order of mm to cm). Results from the stress vs displacement curves from indentation indicated that (1) first peak strength decreased, according to a power law, with increasing indenter size and was not affected by snow average grain size, (2) plateau strength decreased with increasing indenter size, and snow compaction strength might be calculated from these data, and (3) mean energy absorption density during indentation was independent of indenter size in some size ranges, and decreased with increasing indenter size in other size ranges.

Comparing measurements of snow mechanical properties relevant for slab avalanche release

“…Nonetheless, from the SMP signal analysis, we do not obtain a truely elastic modulus, but rather an effective modulus. This is partly, because we do not account for geometric scaling due to indenter size (Huang and Lee, 2013). Moreover, we neglect possible snow compaction near the SMP tip (van Herwijnen, 2013; LeBaron and others, 2014) which leads to an overestimation of the deformation energy in the initial phase of deformation.…”

“…Increasing the length of this crack the change in mechanical energy was determined. Fitting pairs of crack length and mechanical energy with a beam equation (Heierli, 2008), we obtained the SMP-derived elastic modulus of the slab, which corresponds to the modulus of a uniform slab showing the same displacement as the layered slab. This modulus is termed SMP-derived elastic modulus of the slab or just SMPderived slab modulus E slab SMP (cf.…”

“…Snow layer densities and thicknesses were available from an adjacent manual snow profile. From the obtained pairs of mechanical energy and corresponding crack length the effective modulus of the snow slab (E slab PTV ) was obtained by fitting an adjusted analytical expression for the mechanical strain energy provided by Heierli (2008).…”

Review of compressed snow mechanics: Testing methods

“…The testing of winter (specifically snow) performance of tires has primarily been outdoors. While snow properties are dependent on external factors, like temperature variation, snowfall, humidity change, etc., it is difficult to replicate the outdoor conditions in the laboratory, so fewer indoor studies exist ( (Huang and Lee, 2013;Lee and Huang, 2015;Peinke et al, 2020)). The usage of numerical methods for the analysis of tire-snow interaction has seen a rise due to a variety of reasons, one of which is the reduction in costs due to experimentation.…”