Wear zone development characteristics and a discrete element method-based zonal quantification method for a ploughshare

To quantify the formation and spatial expansion of wear zones on a ploughshare under different tillage parameters, in this study, a soil‒ploughshare interaction model is established in EDEM 2024 using the discrete element method coupled with the Archard wear model. The effects of tillage speed, tillage depth, and penetration angle on ploughshare force, power consumption and high-wear area distribution are investigated. In accordance with the curved geometry of the ploughshare surface and the soil contact path, the working surface is divided into a cutting zone, a bearing zone, and a diversion zone. The overall and zonal proportions of the high-wear area are extracted, and the time-averaged high-wear area proportion, zonal expansion coefficient and wear area development index (WADI) are constructed. The results show that ploughshare wear is characterized by clear accumulation over time and spatial nonuniformity. The high-wear area first appears near the lower cutting edge and the front lower contact region and then expands towards the middle working surface along the sliding direction of the soil particles. When the tillage speed increases from 1.25 to 2.00 m/s, the overall high-wear area proportion increases from 6.00% to 26.14%, whereas that in the bearing zone increases from 2.55% to 33.19%. When the tillage depth increases from 125 to 200 mm, the overall high-wear area proportion increases from 15.23% to 45.12%, and that in the diversion zone increases from 0.30% to 14.46%, indicating that deep tillage promotes upwards wear expansion. When the penetration angle increases from 30° to 75°, the overall high-wear area proportion decreases from 26.14% to 3.03%, although the relative fluctuation of the load increases. Tillage speed mainly promotes wear expansion by increasing the particle sliding velocity and scouring frequency. Tillage depth increases the wear range by increasing the soil contact volume and contact area. Furthermore, the penetration angle suppresses the development of high-wear areas by changing the contact characteristics and soil flow path. The proposed zonal quantification method involves converting the spatial information in Archard wear contour maps into comparable indices, providing a basis for identifying critical wear zones, optimizing wear-resistant structures, and matching tillage parameters.