In this study, we established an effective finite element model for branch-stem-fruit systems to: (i) simulate responses under different loads; and (ii) intuitively predict the breaking process of branch-stem joints. The constitutive parameters of fruit branches and apple stalks were measured based on the orthotropic transverse constitutive model. Moreover, the maximum traction force, maximum traction displacement and specific fracture energy of the abscission zone were estimated based on the cohesive zone model (CZM). The experimental and simulation results of the branch-stem sample tensile process and horizontal pull test demonstrated the more effortless ability of the tangential load to detach the fruit. Moreover, compared with the horizontal pull tests and simulation results, the maximum relative deviation was less than 10%, revealing that the branch-stem-fruit finite element model can accurately reflect the process of fruit detachment. This research provides a reliable finite element model of the branch-stem-fruit system for future studies on apple harvesting through tree shaking or robotic apple harvesters.

在这项研究中，我们为枝干果系统建立了一个有效的有限元模型：(i) 模拟不同负载下的响应；(ii) 直观地预测枝干关节的断裂过程。基于正交各向异性横向本构模型测量了果枝和苹果茎的本构参数。此外，基于内聚区模型（CZM）估计了脱离区的最大牵引力、最大牵引位移和比断裂能。枝干样品拉伸过程和水平拉力试验的实验和模拟结果表明，切向载荷更容易分离果实。而且，与水平拉力试验和模拟结果相比，最大相对偏差小于10%，揭示枝-茎-果有限元模型能够准确反映果实脱落过程。这项研究为未来通过摇树或机器人苹果收割机收获苹果的研究提供了一个可靠的枝干果系统有限元模型。