Authors

Abstract

The movement of plug seedlings and the pots damage mechanism are deeply studied during the planting process, and the planting components are optimized. The Tekscan pressure distribution measurement system was used to measure the mechanical characteristics of the drop impact between the whole plug seedlings and the pots. The relative error between the collision impact force of the plug seedlings and the collision impact force of the pot is less than 20%. Therefore, a drop impact test using the pot allows the whole plug seedling to be characterized. The Hertz-Mindlin with bonding model was used to build a simulation model of the pot based on essential physical parameters. The Plackett-Burman test and the steepest climbing test determined the significant parameters and optimal intervals affecting the collision impact force: the rolling friction coefficient between the pot and pot was 0.35~0.38, the bond stiffness was 0.2~0.6 MN·m-3, and the bond radius was 1.56~1.98 mm. Finally, the Box-Behnken test was performed and the quadratic regression model of the collision impact force was developed. Taking the collision impact force with a drop height of 350 mm as the target, the optimal solution is obtained: the rolling friction coefficient between the pot and pot was 0.35, the bond stiffness was 0.53 MN·m-3, and bond radius 1.97 mm. The average value was used for other insignificant influence parameters. The simulation results are compared with the physical test, and the relative error is 3.65%. Therefore, the pot model established by this simulation parameter can represent the actual drop impact of the pots.

Abstract in Chinese

为深入研究栽植过程穴盘苗的运动规律和钵体的破损机理，进而优化栽植部件。本文采用Tekscan压力分布测量系统对整株穴盘苗与钵体的跌落碰撞力学特征测定，得到穴盘苗的碰撞冲击力与钵体的碰撞冲击力相对误差小于20%，可得采用钵体的掉落碰撞特性可以表征实际的穴盘苗。然后基于本征参数建立钵体的粘结模型，通过Plcakett-Burman 试验和最陡爬坡试验，确定了影响碰撞冲击力的显著性参数和最优区间：钵体-钵体的动摩擦系数为0.35～0.38、粘结刚度为0.2~0.6 MN•m-3和粘结半径为1.56～1.98 mm；最终对显著性参数进行了Box-Benhken 试验，建立了碰撞冲击力与仿真参数的二阶回归模型，并以跌落高度为350mm 的钵体碰撞冲击力为目标进行寻优，得到最优解：钵体-钵体的动摩擦系数0.36，钵体的粘结刚度0.22 MN•m-3和粘结半径1.66 mm，相对误差为3.65%，即采用此仿真参数建立的穴盘苗钵体模型，能表征实际穴盘苗钵体的跌落碰撞力学特性。