Modeling the Effects of Narrow Blade Geometry on Soil Failure Draught and Vertical Forces Using Discrete Element Method

In most earth moving machinery, such as bulldozers or tillage tools, the working tool is a tine. Thus, for tillage systems, accurate predicting of the forces acting on the tine is of prime importance to enhance their productivity. The initial conditions (i.e., blade geometry or soil type) and operating conditions (i.e., cutting speed and cutting depth) have been shown experimentally a great effect on machinery efficiency. Although experimental studies provide valuable information, they are expensive, time-consuming, and limited to certain cutting speeds and depths. Results obtained from experimental studies are also highly dependent on the accuracy of the measuring devices. However, with the increasing computational power and the development of more sophisticated mathematical models, numerical methods and in particular discrete element method (DEM) have shown great potential in analyzing the factors affecting soil-blade interaction. In this study, the effects of different rake angles, forward speed, working depth, and depth/width (d/w) ratio were investigated on a tine draught and vertical force using DEM modeling. Simulation results were also compared with the test results. It was found from the results that increasing travel velocity, tine rake angle, d/w ratio, and working depth increased draught and vertical force. Overall, based on the results of this study, DEM is able to predict soil reaction forces with an accuracy of more than 90%.