| Summary: | 碩士 === 國立臺北科技大學 === 機電整合研究所 === 104 === In the past few years, high precision products have shown its potential in product development. Rotational driving of machine tool which involves vibration is the major cause of poor accuracy. Therefore, to find a better way to attenuating vibration is urgent and important. Generally, most modern machine tools do not operate in single-frequency only, and the recent trend of green energy research grows rapidly. How to harvest the vibration energy for a certain frequency span becomes an interesting topic. In this research, we use tunable vibration absorber (TVA) to attenuate vibration from main platform structure. By changing tip mass of the absorber, we can control the natural frequency of cantilever beam structured absorber. In the meantime, the application of piezoelectric material can harvest the vibration energy generated by absorber. In order to attenuating vibration, we tune the natural frequency of absorber to the exciting frequency. Moreover, theoretical model of absorber was built to investigate the difference in using dynamic and static mode shapes for design analysis, and find the optimized length of piezo material to harvest maximum electric power. In order to attenuate the vibration of different modes for the platform structure, the location of absorber on the platform was specified accordingly. The results demonstrate that this vibration absorber can reduce the vibration of three modes related to Z-axis translation (30.5Hz), X-axis rotation (42Hz) and Y-axis rotation (52.75Hz) of the platform, and have notable effect in harvesting vibration energy.
|
|---|
