基于Tavares模型的多面体棉籽离散元参数标定与试验OA北大核心CSTPCD

Aiming to address the lack of an accurate simulation model for the compression and crushing process of cottonseed,based on the discrete element method,the Xinluzao 84 cottonseed was used as the research object,and its parameters were calibrated through the combination of physical tests and simulations.According to the actual morphological characteristics of cottonseed,the volume of cottonseed was calculated by using the average particle size to represent the size of cottonseed in the vertical length direction,and the result was less error with the volume obtained by using the triaxial dimensions,which proved that it was reliable to use the average particle size to describe the size of cottonseed in the vertical length direction.The polyhedral model of cottonseed was rapidly constructed by using the mesh modelling function in Solidworks 2022.The correlation was established between the volume relative error,simulation time,and the number of facets of the model.It was determined that the optimal number of facets for the polyhedral cottonseed model was 1 098,with corresponding simulation time of 171 minutes and volume relative error of 0.46%.The stacking angle test was employed to calibrate the interspecific parameters of cottonseed.The results indicated that the collision recovery coefficient of cottonseed-cottonseed,the static friction coefficient of cottonseed-cottonseed,and the rolling friction coefficient of cottonseed-cottonseed had a significant effect on the stacking angle.The optimal parameter combinations were determined to be 0.106,0.248,and 0.105,respectively.Relative error of 0.28%was observed between the simulation stacking angle and the actual stacking angle when using these parameter values,demonstrating the accuracy of the cottonseed parameters.The parameters of the Tavares model were calibrated and verified by the indexes of cottonseed crushing force and crushing energy through the single particle compression test.The results showed that the relative errors of cottonseed crushing force and crushing energy were 2.37%and 2.87%,respectively.This indicated that the constructed cottonseed model and the calibrated parameters of the Tavares model were able to effectively characterize the compression and crushing process of cottonseed.