Damping Characteristics and Tribological Properties of Machine Structure Considering the Small Vibration Control

本课题针对机械结构的小振动控制进行研究。由于机床结构是由若干部件组成的，因此研究这些部件之间的接触机理对提高机床结构的阻尼特性具有重要意义。然后，用精密机床虎钳将结构材料固定在夹块之间，并在增加脉冲输入时检测结构材料的阻尼特性和接触刚度。其次，通过实验研究了将球插入结构的空心部分时的阻尼特性。首先用冲击锤对空心结构或球填充结构进行激励，根据响应波形估计其阻尼特性；通过实验得到了结构的接触刚度和阻尼特性。首先，接触部分的阻尼特性随输入和夹紧载荷的变化而变化，从阻尼特性判断存在最佳夹紧条件。当夹紧载荷较低时，这些零件之间会发生宏观滑移，从而获得较大的阻尼能力。当夹紧载荷较大时，会产生微滑移，阻尼能力略有下降。后一种阻尼状态对实际工程运行具有重要意义。对这些阻尼能力的解释是从与微颗粒的表面接触点出发的。此外，球材料的种类、球的尺寸和球的填充密度对球填充结构的阻尼特性也有影响。此外，已经了解到，插入球的材料、球的尺寸和球的填充密度大大改善了振动特性。

This research aims at the small vibration control of the machine structure. The machine structure combines some components, so it is important for improving the damping characteristic of the structure to examine the contact mechanism between these materials. Then, the structural material is fixed between the holder blocks with the precise machine vise, and the damping behavior and the contact rigidity are examined when the impulse input is added. In the next place, the damping characteristic is examined experimentally when the balls are inserted into the hollow part of the structure. First of all, the hollow structure or the structure packed with balls is excited with the impact hammer, and the damping behavior is estimated from the response wave form.As a result, the contact rigidity and the damping characteristic of the structure are obtained from these experiments. First of all, the damping characteristic in the contact part changes by the input and the clamping load, and it has been understood that the optimum clamping condition is existed judging from the damping characteristic. When the clamping load is low, a macro-slip between these parts occurs and large damping capacity is obtained. When the clamping load is high, a micro-slip occurs and damping capacity is reduced a little. Latter state of damping is important for real engineering operation. The explanation of these damping capacities is carried out from the point of surface contact with micro-asperities. Moreover, the damping characteristics of the structure packed with balls are influenced by the kind of the ball material, the ball size, and the packing density of the balls. In addition, it has been understood that the vibration characteristic is greatly improved by the inserted ball material, the ball size, and the packing density of the balls.