DISCRETE ELEMENT METHOD SIMULATION OF FORCE DISTRIBUTION ON THE COVERING DEVICE OF A TREE PLANTING MACHINE

This study uses discrete element method (DEM) simulations to examine how soil type, moisture content, and working speed affect forces on a tree planting machine’s covering paddle, this method was applied to mimic real-world conditions and optimize working parameters. Maximum paddle forces increased from 263 N to 589 N across soil types and moisture contents, with higher water content and faster speeds increasing loads, especially in sandy soils. For example, in sandy soil, increasing moisture from 0% to 50% raised forces from 276 N to 392 N at 1 km/h and from 300 N to 589 N at 3 km/h. Clay soils showed generally lower forces (263445 N). All measured forces remained within design limits, the objective was to establish a quantitative relation between soil moisture, working speed, and paddle reaction forces, highlighting their importance to ensure consistent seedling placement, minimize wear, and enhance equipment longevity.