Analysis of energy transfer characteristics in multi-level branches of Lycium barbarum L. under vibration excitation

Aiming at the problems of unknown vibration energy transfer mechanism and high risk of branch damage in the process of mechanised harvesting of Lycium barbarum L. (L. barbarum), this study took the typical secondary bifurcation structure of L. barbarum branches as the object, and analysed the influence law of the branch length ratio, diameter ratio and clip angle on the efficiency of energy transfer through the establishment of a mathematical model and the combination of MATLAB simulation. A self-made vibration excitation loading device, combined with flexible acceleration sensors and high-speed camera device, was used to measure the three-dimensional vibration response accurately. The results show that: the experimental results are basically consistent with the simulation results, and the square of the primary-secondary branch diameter ratio and the length ratio are positively correlated with the energy transfer efficiency; based on the modified mathematical model of the inter-branch angle and acceleration ratio, it is known that the inter-branch angle in the range of 0 ∼ 90° has a significant nonlinear inhibitory effect on the energy transfer efficiency; and the acceleration value of the tertiary branches in the range of 765.36 ∼ 1224.58 m/s² were achieved for effective harvesting; in vibration harvesting operation, vibration of tertiary branches compared to vibration of the primary trunk, the excitation force can be reduced by 48.16 % ∼ 79.75 %, effectively avoiding the risk of damage to the branches of L. barbarum. The results of the study provide a theoretical basis for the structural design of low-damage vibration harvesting equipment for L. barbarum.