玉米种子与脱粒部件碰撞过程中的接触力学分析

Contacting Mechanics Analysis during Impact Process between Corn Seeds and Threshing Component

为进一步分析脱粒过程中玉米种子机械应力裂纹的产生机理,为新式种用脱粒机的研制提供理论支持,运用赫兹理论和材料力学分析了玉米种子产生机械脱粒损伤的临界速度,分析了脱粒部件与玉米种子的力学接触过程,并进一步比较了不同脱粒部件与玉米种子的碰撞过程。研究发现:玉米种子与脱粒部件相互接触时的相对运动速度大于Vz时,玉米种子将产生机械应力裂纹,甚至破碎;钉齿和板齿及其上不同部位对玉米种子的力学作用效果存在明显差异;玉米种子与脱粒部件的接触面积越大,受到的打击力就越大,且钉齿对玉米种子的打击力大于板齿的打击力。

In order to further analysis mechanical stress crack formation mechanism of corn seeds duringthreshing process, provide theory support for the development of new maize seed sheller. In this paper, Hertztheory and mechanics of materials were used to analyses the critical velocity of corn seeds generated flexcracks, and the contacting process between corn seeds and threshing parts, and compared the collision processbetween spike tooth and plank tooth and maize seeds. It is shown that corn seeds would be producingmechanical stress cracks, even broken when the relative speed of corn seeds and threshing parts touch eachother is greater than Vz; there are significant different mechanical effect between different threshing parts anddifferent parts and corn seeds; contact area of corn seeds and threshing unit greater, the impact force receivedby corn seeds greater, and impact force of spike tooth greater than plank tooth.