Theoretical analysis and multiscale finite element simulation of the dynamic behavior of maize kernel impact on threshingtooth

摘要

Internal crack damage of corn caused by threshing impact is the main source of mechanical damages in further processing and it caused great qualimaizety loss to corn products. This study focuses on predicting the internal crack damages of maize kernelhorny endosperm, floury endosperm and germ tissues under various threshing impact cases. A reverse engineering (RE) approach of Non-Uniform Rational B-Splines (NURBS) based lofting computer aided design (CAD) technology, multiscale finite element method(FEM) based explicit dynamics simulation were utilized to visualize, digitalize and study the dynamic impact behavior, internal stress distribution and energy transformation characteristics of the corn kernel. Results revealed that the multiscale FEM based on multibody model was able to predict the internal crack damage of maize kernel tissues with a maximum relative error of 13.58%. The crack damage of the floury endosperm was found to be generated prior to horny endosperm and germ tissues when suffered impact load. The crack damage of horny endosperm began at the contact surfaces between the kernel and threshing unit and then spread wide and inside, The crack damage of floury endosperm and germ began at the commissural surfaces approached the contact area. The terminal velocities of horny endosperm, floury endosperm and germ were determined as 15.92, 12.24 and 17.84 m/s, respectively. This study contributes to further research on reducing the crack damage of maize kernel during threshing processing.