Simulation model and application of shear force of citrus shank based on LS-DYNA

Abstract The citrus fruit harvesting typically employs shearing techniques to separate the fruit from its fruit stalk, necessitating an investigation into the interaction patterns between shear forces and related factors. In this study, simulation analysis of the mechanical process of citrus fruit stalk shearing based on LS-DYNA was conducted. The results demonstrate that the relative error between the simulation outcomes and the shear test measurements remained below 15%, indicating the shear model exhibited a high accuracy. Based on this foundation, applied researches based on simulation models were conducted: a regression model between peak shear force and various parameters (the fruit stem diameter, the fruit stalk inclination angle, and the cutting tool gap) was established, enabling the prediction of the peak shear force during citrus fruit stalk shearing under different conditions. The study revealed the influence patterns of each shear parameter: the increased fruit stalk diameter significantly boosted the peak shear force; the shear force decreased as the cutting tool gap increased within specific ranges; the increased fruit stalk inclination angle initially enhanced but subsequently diminished the shear force. The influence weights order of the three factors on the peak shear force was: fruit stalk diameter>fruit stalk inclination angle> tool gap. This research provides crucial theoretical support for optimizing citrus fruit stem shearing process parameters and offers a practical value in guiding the design and development of the picking machinery.