Calibration and Experimental Validation of Contact Parameters in a Discrete Element Model for Tobacco Strips

To study the contact parameters of the tobacco strips during redrying, in this study, the funnel stacking test is used to determine the stacking angle, and the discrete element method is used to simulate the formation process of the stacking angle, to calibrate and verify the physical and contact parameters of tobacco strips. The Placket-Burman test was used to screen out the parameters that had significant effects on the stacking angle. The regression response surface model between the stacking angle and contact parameters was established by Central Composite Design using the stacking angle from physical tests as the response index. The test results show that static and rolling friction coefficients between tobacco strips have significant effects on the test results, so these two parameters must be accurately calibrated. Finally, the accuracy and validity of the calibrated tobacco strips contact parameters were verified by comparing the stacking angle and void ratio of physical and simulation experiments. The calibration results can provide basic parameters for studying the interaction and motion of the tobacco strips in the redrying process using simulation methods.