控释肥颗粒群仿真接触参数标定与试验

接触参数影响控释肥颗粒离散元仿真结果。为了精准模拟控释肥颗粒力学行为与运动规律，本文基于离散元法对控释肥颗粒的接触参数进行标定与试验。首先，建立控释肥离散元基础模型，并利用台架和仿真试验相结合的方法，在EDEM中对控释肥颗粒与PVC板之间接触参数进行标定。其次，通过碰撞弹跳试验、斜面滑移试验和斜面滚动试验测得控释肥颗粒与PVC板之间的碰撞恢复系数、静摩擦因数和滚动摩擦因数分别为0.539、0.507和0.105。最后，通过堆积试验、最陡爬坡试验和正交旋转组合试验，得到控释肥颗粒间的碰撞恢复系数、静摩擦因数和滚动摩擦因数分别为0.38、0.25和0.09，并通过无底圆筒提升试验和排肥台架试验进行验证。试验结果表明，堆积角实际值与仿真结果的相对误差为1.54%，排肥量实际值与仿真结果4种转速下的相对误差分别为4.38%、4.23%、4.41%、4.36%，所标定的控释肥接触参数精准有效，可为控释肥离散元仿真提供数据和模型支撑。

Simulated Contact Parameters Calibration and Experiment of Controlled-release Fertilizer Particles

The contact parameters affect the discrete element simulation results of controlled-release fertilizer particles. In order to accurately simulate the mechanical behavior and motion law of controlled-release fertilizer particles, the contact parameters of controlled-release fertilizer particles were calibrated and experimented based on the discrete element method. Firstly, the basic model of controlled-release fertilizer discrete elements was established, and the contact parameters between controlled-release fertilizer particles and PVC panels were calibrated in EDEM by combining bench and simulation experiment. Secondly, the collision recovery coefficient, static friction factor and rolling friction factor between controlled-release fertilizer particles and PVC plate were measured by collision bounce experiment, slope slip experiment and inclined rolling experiment to be 0.539, 0.507 and 0.105, respectively. Finally, through the accumulation experiment, the steepest climbing experiment and the orthogonal rotation combination experiment, the collision recovery coefficient, static friction factor and rolling friction factor between controlled-release fertilizer particles were obtained as 0.38, 0.25 and 0.09, respectively, and verified by bottomless cylinder lifting experiment and fertilizer discharge bench experiment. The experiment results showed that the relative error between the actual value of the accumulation angle and the simulation result was 1.54%, and the relative error between the actual value of the discharge amount and the simulation result at the four speeds was 4.38%, 4.23%, 4.41% and 4.36%, respectively, and the contact parameters of the calibrated controlled-release fertilizer were accurate and effective, which can provide data and model support for the simulation of controlled-release fertilizer discrete elements.