CAJ | 학술논문

　　玉米种子的滚动摩擦系数是排种器设计计算和仿真分析的重要依据，但其测量目前尚无成熟的理论与方法。该文基于能量守恒原理，借助高速摄像技术对玉米种子与有机玻璃、镀锌钢板以及玉米种子间的滚动摩擦特性进行了试验研究，得到玉米种子与有机玻璃、镀锌铁板以及玉米种子间的滚动摩擦系数分别为0.0931、0.0531和0.0782。通过玉米种子休止角试验和离散元分析软件EDEM仿真结果的对比，对所得试验数据进行了验证，结果表明所得数据准确性较高，可为排种器的设计计算与仿真分析提供理论依据。
　　옥미충자적곤동마찰계수시배충기설계계산화방진분석적중요의거，단기측량목전상무성숙적이론여방법。해문기우능량수항원리，차조고속섭상기술대옥미충자여유궤파리、도자강판이급옥미충자간적곤동마찰특성진행료시험연구，득도옥미충자여유궤파리、도자철판이급옥미충자간적곤동마찰계수분별위0.0931、0.0531화0.0782。통과옥미충자휴지각시험화리산원분석연건EDEM방진결과적대비，대소득시험수거진행료험증，결과표명소득수거준학성교고，가위배충기적설계계산여방진분석제공이론의거。
The physical properties of corn seeds, including the dimension feature, density, Poisson’s rate, shear modulus, coefficient of restitution, coefficient of static fraction, and coefficient of rolling fraction are vital to the design of the precision seed-metering device and the simulation of its working process. There have been many relative studies on them, but no mature theory and accurate method to measure the coefficient of rolling friction has been developed. Due to the shape and dimension character limitation, most methods for measuring the coefficient of rolling fraction are not applicable to corn seed. Only one method based on the principle of conservation of energy gave some enlightenment on the way to achieve it. The method and principle used to obtain the coefficient of rolling friction was:A static spherical corn seed rolls from the top of an inclined rail to the end. The gravitational potential energy (U) of the seed on the top is equal to the kinetic energy at the end (Ek) and the work done by the rolling friction within this distance (Wfr). And the ratio of Wfr and U(WCU=) has a linear relation with cotθ(θis the angle of the inclined rail). The equation fr f of linear regression can be fitted by changingθeight times from 15°to 50°, the slop of the straight line just is the coefficient of rolling friction. U can be calculated by the distance of the inclined rail andθeasily, but Ek needs the aid of high-speed photography technology to capture the velocity of the seed at the end. The experimental materials included several selected spherical corn seeds that were used as roll ball, an angle adjustable frame of rail, and three rails which were made of the PMMA (polymethyl methacrylate), galvanized steel, and corn seeds respectively. The main testing equipment was the Phantom v9.1 high-speed camera, which was produced by Vision Research. The frame rate used in the experiment was 1 000 fps. According to the results of the experiment, the coefficient of rolling friction of corn seeds against PMMA (polymethyl methacrylate), galvanized steel, and corn seeds are known as 0.0931, 0.0531 and 0.0782 respectively. Although there were some inevitable errors caused by the materials and image processing method for getting the velocity, the results were proved to be truthful by the contrast tests about the angle of repose for corn seeds both by laboratory tests and EDEM simulation. The data measured can be used for design calculation and simulation analysis.