Ghonimy Mohamed, Alharbi Abdulaziz, Ibrahim Mohamed M
Department of Agricultural and Biosystems Engineering, College of Agriculture and Food, Qassim University, Buraydah, 51452, Saudi Arabia.
Department of Environment and Natural Resources, College of Agriculture and Food, Qassim University, Buraydah, 51452, Saudi Arabia.
Sci Rep. 2025 Apr 4;15(1):11615. doi: 10.1038/s41598-025-96515-4.
This study investigates the damping behavior of olive trees under trunk shaking by assessing transmitted acceleration and logarithmic decrement in the soil and tree, as well as the actual shaking, damping, and elastic powers within the tree. The trunk shaker was operated at five attachment heights: 0.4, 0.5, 0.6, 0.7, and 0.8 m. Results revealed that the peak elastic power of 8.8 kW occurred at 0.8 m, after which elasticity declined, indicating that the tree reaches its maximum elastic capacity before inertia dominates. The transmission of acceleration to the root-soil system is influenced by attachment height and trunk diameter, with larger diameters and lower attachment points reducing transmitted acceleration. The highest transmitted acceleration of 30.7 m·s was measured at 0.8 m. Along the x-axis, acceleration progressively increases from the base to the branches, while the y-axis is mostly absorbed by the trunk. Additionally, the logarithmic decrement decreases with distance from the shaker, reflecting greater damping in the trunk compared to the branches. These findings suggest that optimizing attachment height during mechanical harvesting can enhance energy efficiency and minimize damage by improving elastic responses and managing acceleration and damping dynamics.
本研究通过评估土壤和树木中的传递加速度和对数衰减,以及树木内部的实际振动、阻尼和弹性功率,来研究油橄榄树在树干摇动下的阻尼行为。树干振动器在五个附着高度下运行:0.4、0.5、0.6、0.7和0.8米。结果表明,8.8千瓦的峰值弹性功率出现在0.8米处,此后弹性下降,这表明在惯性占主导之前,树木达到了其最大弹性容量。加速度向根-土系统的传递受附着高度和树干直径的影响,直径越大且附着点越低,传递的加速度越小。在0.8米处测得的最高传递加速度为30.7米·秒²。沿x轴,加速度从基部到树枝逐渐增加,而y轴的加速度大多被树干吸收。此外,对数衰减随与振动器距离的增加而减小,这反映出树干中的阻尼比树枝中的更大。这些发现表明,在机械采收过程中优化附着高度可以通过改善弹性响应以及控制加速度和阻尼动态来提高能源效率并将损害降至最低。