南疆骏枣园表层土壤与梳齿互作仿真接触参数研究

Study on simulation contact parameters of interaction between topsoil and comb teeth in jun-jujube orchard in south Xinjiang

为提高机械式落地红枣捡拾机触土部件梳齿入土作业过程离散元模拟的准确性,确定离散元试验中沙土与梳齿的互作仿真接触参数,本文以沙土-沙土间接触参数、沙土-梳齿(钢)间接触参数为试验因素,以沙土休止角和滑动摩擦角为指标,分别建立沙土休止角试验和沙土滑动摩擦角试验,利用Design-Expert软件开展Central Composite Design试验研究,以实际沙土休止角和滑动摩擦角为优化目标,获得最优接触接触参数组合为沙土-沙土恢复系数0.215、静摩擦系数0.611、滚动摩擦系数0.217,沙土-钢之间恢复系数0.375、静摩擦系数0.328、滚动摩擦系数0.125。通过对机械式落地红枣捡拾机开展沙土间田间试验与仿真试验,经验证土垄堆积高度试验误差不超过15%,确定了沙土参数标定的可靠性。本文研究结果可为后续机械式落地红枣捡拾机离散元仿真提供参数参考。

In order to improve the accuracy of the discrete element simulation of the process of inserting the comb teeth entering the soil of the mechanical floor-standing jujube picker,the interaction simulation contact parameters of sandy soil and comb teeth in the discrete element test.The contact parameters between sandy soil and sandy soil and between sandy soil and comb teeth(45 steel)are taken as the test factors,and the angle of repose and sliding friction angle of sand and soil as indicators,the Central Composite Design test is carried out by using Design-Expert software.Taking the actual repose angle and sliding friction angle of sandy soil as the optimization objectives,the optimal contact parameter combinations were obtained as sandy soil-sand soil recovery coefficient 0.215,static friction coefficient 0.611,rolling friction coefficient 0.217,sand-steel recovery coefficient 0.375,static friction coefficient 0.328,rolling friction coefficient 0.125.Through the comparison between the field soil ridge stacking height test and the simulation test of the mechanical floor-standing jujube picker.The error of the soil ridge stacking height test was verified to be less than 15%,and the reliability of sand soil parameter calibration was determined.It can provide parameter reference for the subsequent discrete element simulation of the mechanical floor-standing jujube picker.