NUMERICAL INVESTIGATION OF GROSS TRACTION GENERATED AT GROUSER-SOIL INTERFACE BY DEM

摘要

The cross-section shape of a single grouser shoe is one of governing factors for generating gross traction of tracked vehicles working on deformable terrain. Previous studies revealed that not only the height of grouser but also the thickness of grouser affected the gross traction, although the sinkage of grouser was fixed against the ground contact load. To obtain an insight into the slip-sinkage effect of a grouser, we applied 2D DEM to an analysis of gross traction, where the grouser thickness and height were varied as contributing factors for gross traction. In the analysis, dry sand was modelled by a mixture of discrete elements of two representative radii, and the replacement of contact-based rolling friction subroutine by increased polar moment was introduced, and the frequency of element allocation into indexes was reduced to update the in-house 2D DEM code in terms of computational economy. Numerical results showed larger gross traction for smaller thickness ratio λ and for increasing grouser height, which differed from the result of experiments where clear peak of gross traction was observed for λ = 0.1. In case of λ= 0.5, deteriorating behavior of gross traction can be seen in DEM as in the experiments. Moreover, generated gross traction in DEM mostly came from the action of vertical face of grouser height in case of λ = 0.1.