Structural Design and Arrangement Optimization of Low-Resistance Power Harrow Tines Based on Discrete Element Method

This study aimed to address the issues of high tillage resistance and uneven force distribution caused by conventional tine arrangements during the operation of driven harrows. The effects of tine structural parameters and arrangement patterns on operating resistance were systematically investigated through a combination of three-dimensional force analysis and simulation tests. Tine structure parameters were optimized, with tine rake angle, blade inclination angle, inner bending angle, and chamfer angle set as variables, and the mean force on the tine taken as the response value. The following optimal structural parameter combination was obtained via simulation tests: tine rake angle 0°, blade inclination angle 0.014°, inner bending angle 15°, and chamfer angle 10.04°, under which the mean force was determined to be 205.81 N. On this basis, a specific tine arrangement pattern was proposed. Based on single-tine force analysis, a resultant force model for eight groups of tines was established by means of phase angle superposition. With the standard deviation of the resultant force and the average of the maximum force values being adopted as multi-objective responses, the arrangement parameters were optimized. The results showed that when the initial mounting angle was set to 104° and the arrangement angle to 125°, the force standard deviation of the system was 79.48 N, and the average of the maximum force values was 1329.98 N, corresponding to the minimum fluctuation in operating resistance and the most uniform load distribution. This study provides a theoretical basis for the structural design and arrangement optimization of driven harrow tines, which is conducive to improving operational stability and tillage efficiency.