The current commercial technologies for mass harvesting fruit are based on the application of forced vibration to the tree, which is transmitted to the fruits causing their detachment. The dynamic behaviour of the plant under forced vibration is of special interest to improve the design and use of the machinery. The objective of this work is to determine the effect of fruit and leaves on the dynamic response of the citrus branch. In this study, 22 secondary branches of ‘Valencia’ sweet orange trees were tested by applying forced vibration and measuring the response of the branches with triaxial accelerometers. The branches were tested in three stages: in-fruit branch, out-of-fruit branch and out-of-leaf branch. Three natural frequency values were identified in the branches, and were established as 2, 7 and 11 Hz. Acceleration transmissibility along the branch decreased as vibration frequency increased. The acceleration transmission values were highest for the first natural frequency, and were up to 1.3-fold greater in the out-of-fruit branch and up to 4.6-fold greater in the out-of-leaf branch. The presence of fruits on the branch did not modify the branch natural frequency values but did slightly reduce the values of acceleration transmissibility. However, the presence of leaves on the branches had a double effect, reducing the first natural frequency and drastically damping acceleration transmissibility.

中文翻译：

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果叶对橙树次生枝条动态响应的贡献

当前用于大量收获果实的商业技术基于对树施加强制振动，该振动被传递到果实导致它们脱离。受迫振动下设备的动态行为对于改进机械的设计和使用具有特殊意义。这项工作的目的是确定果实和叶子对柑橘枝条动态响应的影响。在这项研究中，通过施加强制振动和用三轴加速度计测量树枝的响应来测试 'Valencia' 甜橙树的 22 个次生树枝。对枝条进行了三个阶段的测试：果内枝、果外枝和叶外枝。在分支中确定了三个固有频率值，并确定为 2、7 和 11 Hz。随着振动频率的增加，沿分支的加速度传递率降低。第一固有频率的加速度传递值最高，在果外枝中高达 1.3 倍，在叶外枝中高达 4.6 倍。树枝上果实的存在并没有改变树枝的固有频率值，但确实略微降低了加速度传递率的值。然而，树枝上叶子的存在具有双重效果，降低了第一固有频率并大大降低了加速度的传递性。树枝上果实的存在并没有改变树枝的固有频率值，但确实略微降低了加速度传递率的值。然而，树枝上叶子的存在具有双重效果，降低了第一固有频率并大大降低了加速度的传递性。树枝上果实的存在并没有改变树枝的固有频率值，但确实略微降低了加速度传递率的值。然而，树枝上叶子的存在具有双重效果，降低了第一固有频率并大大降低了加速度的传递性。