Authors

Abstract

This paper focuses on the lack of spherical-like soybean simulation parameters when guiding the optimization and design of agricultural machinery and equipment through discrete element simulation. The spheroidal soybean variety SN29 was used as a study subject; the intrinsic properties and physico-mechanical properties of the spherical soybean were determined through actual measurements and the simulation of spherical-like soybean particles with Hertz-Mindlin (no-slip) as the contact model was established. The collision recovery, static, and rolling friction coefficients of the spherical-like soybean and acrylic sheet material were measured by the natural drop and inclined plane methods, combined with discrete element simulation and bench experiments. They were 0.474, 0.496, and 0.0361, respectively. The relative errors between the measured stacking angles and the simulated stacking angles were used as indicators, and the contact parameters between the particles were used as variables for the design of the steepest climb experiment. The collision recovery coefficient, static friction coefficient, and rolling friction coefficient between spherical-like soybean particles were determined to be 0.35, 0.30, and 0.074, respectively, by orthogonal rotational combination experiment and multi-objective optimization. The relative error between the simulated and measured stacking angles was only 1.09%, as verified by the experiment. This proves that the discrete element simulation parameters of the studied spherical-like soybean can reflect its real characteristics and be used as the parameter basis for discrete element simulation.

Abstract in Chinese

针对类球形大豆在应用离散元仿真指导相关农机设备优化设计时缺乏仿真参数的问题。以类球形大豆品种SN29为研究对象，通过实际测量和万能试验机，确定了类球形大豆的本征特性与物理力学特性，并建立了以Hertz-Mindlin（no-slip）为接触模型的类球形大豆仿真颗粒模型。通过跌落法和斜面法，结合离散元仿真及台架试验，测得类球形大豆与亚克力板材料的碰撞恢复系数、静摩擦系数和滚动摩擦系数，分别为0.474、0.496和0.0361。以实测与仿真堆积角的相对误差为指标，颗粒间接触参数为变量，设计了最陡爬坡试验，并通过正交旋转组合试验及多目标优化，确定了类球形大豆颗粒间的碰撞恢复系数、静摩擦系数和滚动摩擦系数，分别为0.35、0.30和0.074。经试验验证，仿真堆积角与实测堆积角的平均相对误差仅为1.09%。这证明了研究所得的类球形大豆离散元仿真参数能够反映其真实特性，可作为离散元仿真时的参数依据。