Abstract: In order to determine the physical parameters required for discrete element simulation of seed metering device of Notopterygium, the physical parameters of seeds and pearlite of Notopterygium were measured and calibrated. The static friction coefficient was measured using the inclined plane method, the collision recovery coefficient was measured using the free drop method, the accumulation angle was measured using the cylinder lifting method, the accumulation angle was compared by EDEM simulation to determine the rolling friction coefficient, and the accuracy of the measured parameters was determined by comparing the results of simulation test and field test. The grain density of Notopterygium seeds was 160 kg/m3, and the pearlite density was 150 kg/m3. The Poissons ratio of Notopterygium seeds was 0.32, and that of pearlite was 0.2. The shear modulus of Notopterygium seeds was 30 MPa, and that of pearlite was 38.5 MPa, the static friction coefficient between Notopterygium grain and ABS plastic plate was 062, the static friction coefficient between pearlite and ABS plastic plate was 0.78, the static friction coefficient between Notopterygium grain and ABS plastic plate was 0.51, the static friction coefficient between pearlite was 0.91, and the static friction coefficient between Notopterygium grain and pearlite was 0.72. The collision recovery coefficient between Notopterygium grain and ABS plastic plate was 0.39, the collision recovery coefficient between pearlite and ABS plastic plate was 0.28, the collision recovery coefficient between Notopterygium grain was 0.31, the collision recovery coefficient between pearlite was 0.14, the collision recovery coefficient between Notopterygium grain and pearlite was 0.32, and the collision recovery coefficient between pearlite and Notopterygium grain was 0.26. The rolling friction coefficient of Notopterygium seeds was 0.043, the rolling friction coefficient of pearlite was 0.097, the rolling friction coefficient between pearlite and Notopterygium seeds was 0.037. The result curves of simulation test and field test were consistent, whereby the average relative errors were 5.6% and 3.8%, respectively, which showed that the measured physical parameters were reliable. This study provides a theoretical reference for the discrete element simulation of Notopterygium seeds and pearlite, while providing a guide for design optimization of Notopterygium seeder.

Key words: Notopterygium seeds, pearlite, EDEM, parameter calibration, stacking angle, drilling

摘要： 为确定羌活种子排种器离散元仿真所需的物性参数，对羌活籽粒和珍珠岩进行物性参数测量及标定。采用斜面法测量静摩擦系数，用自由跌落法测量碰撞恢复系数，用圆筒提升法测量堆积角，通过EDEM仿真对比堆积角大小，确定滚动摩擦系数，通过对比仿真试验与田间试验的结果，确定测定参数的准确性。羌活籽粒的密度为160 kg/m3，珍珠岩密度为150 kg/m3；羌活籽粒的泊松比为0.32，珍珠岩的泊松比为0.2；羌活籽粒的剪切模量为30 MPa，珍珠岩的剪切模量为38.5 MPa；羌活籽粒与ABS塑料板的静摩擦系数为0.62，珍珠岩与ABS塑料板的静摩擦系数为0.78，羌活籽粒间的静摩擦系数为0.51，珍珠岩间的静摩擦系数0.91，羌活籽粒对珍珠岩的静摩擦系数为0.72；羌活籽粒与ABS塑料板的碰撞恢复系数为0.39，珍珠岩与ABS塑料板的碰撞恢复系数为0.28，羌活籽粒间的碰撞恢复系数为0.31，珍珠岩间的碰撞恢复系数为0.14，羌活籽粒对珍珠岩的碰撞恢复系数为0.32，珍珠岩对羌活籽粒的碰撞恢复系数为0.26；羌活籽粒的滚动摩擦系数为0.043，珍珠岩的滚动摩擦系数为0.097，珍珠岩与羌活籽粒之间的滚动摩擦系数为0.037；仿真试验与田间试验的排种结果曲线基本一致，平均相对误差分别为5.6%和3.8%，表明测定的物性参数具有可靠性。本研究为羌活籽粒和珍珠岩的离散元仿真提供理论参考，为羌活播种机的设计优化提供理论参考。

关键词: 羌活籽粒, 珍珠岩, EDEM, 参数标定, 堆积角, 条播