|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1999 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1998 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1997 : ¥1,900,000 (Direct Cost : ¥1,900,000)
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 bee
n 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.