DEM-MBD coupling simulation of the effect of soil moisture content on mobility performance of tracked chassis

ObjectiveTo reveal the influence mechanism of soil moisture content on the mobility performance of agricultural tracked chassis, and clarify the mutation threshold of critical performance indexes.MethodThis study established a soil-track interaction model via discrete element method-multibody dynamics (DEM-MBD) coupling simulation using a generic agricultural tracked chassis. Soil-DEM parameters were calibrated using an pile angle test. Simulations were conducted for soils with moisture contents (ω) of 5%, 10%, 15%, and 20% to analyze the dynamic responses of vehicle speed, sinkage, axial offset displacement, traction, drive torque and attitude angles (pitch angle and roll angle) during traversal. ResultThe chassis traveled stably on low-moisture (≤15%) surfaces, with an average speed of 0.85 to 0.88 m·s−1 and a coefficient of variation (CV) ≤ 1.09%. At higher moisture content (20%), the speed decayed to 0.61 m·s−1 and the CV rose sharply to 7.90%, with 15% moisture content identified as the stability threshold. For moisture contents from 5% to 15%, steady-state sinkage increased gradually from 70 mm to 150 mm; for 15% to 20% it rose sharply to 370 mm. Axial offset displacement remained ConclusionThis study quantitatively analyzes the critical threshold of soil moisture content and the nonlinear response mechanism of undercarriage performance, providing a theoretical support for the adaptive design of tracked undercarriages and the optimization of field operations.