林果振动加速度响应振型试验

在林果振动采收过程中,激振能量传递至果实处使其获得加速度形成惯性力,当惯性力大于果柄结合力时果实脱落。针对室内小型林果树,通过激振树干对树枝上的加速度响应进行了试验研究。结果表明:树干、一级侧枝A、两个二级侧枝的加速度与激振频率均成二次曲线增长关系,一级侧枝A的加速度值随着测点远离树干分叉点逐渐增大仅在树枝末梢位置出现衰减; 相同的激振频率和测点位置下,一级侧枝B的加速度响应振型与一级侧枝A不同。两个二级侧枝的加速度与测点距树枝分叉点的距离成线性衰减关系。此项研究为深入了解林果树振动响应及振型提供了一定的理论基础。
During the process of the vibration harvesting of fruits, excitation energy is transferred to the fruit and causes its acceleration to form the inertia force. When the inertia force is greater than the connecting force with fruit stalk, the fruit will drop. For the small indoor fruit tree, this paper researched the acceleration response of the branches to the trunk oscillation. The results indicated that all the acceleration on the trunk, first-rank offshoot A and two second-rank offshoots increased quadratically with the increase of excitation frequency. As the monitoring points got away from the bifurcation point, the acceleration value on the first-rank offshoot A gradually increased and only decreased on the peripheral location of the branch. Under the same excitation frequency and monitoring point, the vibration mode of the first-rank offshoot B was different from that of the first-rank offshoot A. The acceleration of the two second-rank offshoots had the linear attenuation relationship with the distance between the monitoring point and the bifurcation point. This research provides a theoretical basis for the further understanding of the vibration response and vibration mode of the fruit trees