关键词: 堆积试验, 针形茶叶, 离散元仿真, 参数标定

Abstract: Aiming at the lack of accurate model parameters in the discrete element simulation of needleshaped tea in the process of stripping machine, which leads to the problem of distortion in the simulation of discrete elements of tea stripping machine, the singlebud tea granules are used as the research object, and the particle model is established based on the approximation method of slicing technology, and the discrete element simulation and the funnel injection method accumulation test are used to calibrate the simulation parameters. Taking the rest angle of tea particles as the response value, the PlackettBurman experiment obtained parameters that had a significant impact on the rest angle of tea particles: collision recovery coefficient between tea particles, static friction coefficient between tea particles and rolling friction coefficient between tea particles. Taking the relative error between the simulation test rest angle and the actual accumulation test rest angle as the goal, the steepest climb test determined the optimal value range of the significance parameter, and the quadratic polynomial equation between the tea particle rest angle and the significance parameter was established by the BoxBehnken test, and the optimal value of the significance parameter was obtained by using the DesignExpert software optimization module: the collision recovery coefficient between tea particles was 0.28, the static friction coefficient between tea particles was 0.15 and the rolling friction coefficient between tea particles was 0.10, and the discrete element simulation verification of the calibration results showed that the average rest angle of tea particles obtained by simulation was 19.52°, which was 3.51% compared with the actual average stop angle of tea particles 20.23°, indicating that the calibration results of this parameter were reasonable and effective. It provides a certain theoretical reference for the optimal design of tea baring machine and the numerical simulation process of tea processing.

Key words: stacking test, needleshaped tea, discrete element simulation, parameter calibration