A Study on Dynamic Simulation of Litchi Pitting Process Based on ANSYS/LS-DYNA

To study the dynamic mechanical changes in litchi pitting process and improve the accuracy of litchi pitting, this paper established a 3-D solid assembly model of litchi, fixture and tool and conducted the finite element discrete of the model by using ANSYS / LS-DYNA software. In addition, the deformations and stress states of litchi's multi-layer structure under the effects of tool and fixture were simulated and calculated by the LS-DYNA971 solver. The results showed that the deformations and stresses of litchi's multi-layer structure changed with the increase of cutting depth, and appeared the maximum amplitude out of sync. When the litchi was gonna cut through, the stress amplitude of fruit pulp was the maximum among litchi's multi-layer structure and the stress amplitude of fruit pulp was the minimum. Pulp would reach its maximum stress when cutting through the litchi, and because of its low strength, the breakage was prone to occur. The stress of fruit stone was large in the initial stage, and big fruit stone was easily led to the breakage for its overlarge stress. In pitting process, the deformation and slippage of litchi would take place with fixture clamping and tool pitting, so this is a complex dynamic deformation process. This study is urgent to make more comprehensive and systematic researches.