Determination of the coefficient of static friction of maize seeds and validation of the discrete element method

In order to provide a basic reference for the design and improvement of maize-related agricultural implements, the coefficients of static friction of maize were determined by the slant method and the direct contact method. The coefficient of static friction between maize seeds determined by the inclined plane method was 0.346 8, that between maize seeds and stainless steel was 0.382 4 and that between maize seeds and plexiglass was 0.421 3. The coefficient of static friction between maize seeds determined by the direct contact method was 0.335 8, that between maize seeds and stainless steel was 0.379 4 and that between maize seeds and plexiglass was 0.423 4. The coefficients of static friction between maize seeds determined by the above two methods had a large error, with a relative error of 3.17%. The experimental results were verified with the help of the discrete unit method software EDEM. The simulation results showed that the coefficient of static friction between maize seeds was 0.312, that between maize and stainless steel was 0.364 and that between maize and plexiglass was 0.388. The simulation results were close to the coefficient of static friction determined by the direct contact method, and the maximum relative error was about 8.36%.