SHALLOW SNOW PERFORMANCE OF TRACKED VEHICLE

Abstract

Compression and shear deformation properties of dry fresh snow and dry age-hardened snow were investigated in a cold room. And those properties of fresh wet snow were tested in-situ using a portable loading plate, and vane or ring shear test apparatus. Then, a shallow snow performance of tracked vehicle was analysed by means of energy equilibrium equation.The experimantal and analytical results obtained here are as follows : (1) Modulus of elasticity and coefficient of propagation of brittle compression of dry fresh snow is an exponential function of initial density.(2) For dry snow, the maximum draw-bar-pull (D.B.P.) of tracked vehicle running on shallow snow terrain is obtained at zero slip ratio, and it increases linearly with average contact pressure. And the influence of snow compaction on its D.B.P. is comparatively small.(3) For wet shallow snow deposit, the maximum D.B.P. is obtained at a few percentage of slip ratio. Both energy losses of compressive deformation and slippage are small. And, there is an optimum average contact pressure in the range of 27.4 to 42.1 kPa, to get a maximum D.B.P..