環境振動反應譜分析之研究

Abstract

本文是在探討如何去建立高科技廠房對環境振動之反應，吾人先利用微振動量測儀器去量測時間域之速度資料，透過快速傅立業轉換(Fast Fourier Transform)將資料轉換到頻率域來做分析，再由速度相關函數的能譜密度函數(Power Spectral Density)，來求得1/3倍頻的速度均方根振動量。而吾人一共在國立交通大學的運動場進行兩次量測試驗，更可以確保資料量測的準確度。 再者，吾人又可以由受到一動態擾動的運動方程式，去求解單自由系統的絕對加速度、絕對速度、及絕對位移的系統反應，然後在再繪製在不同阻尼比下的反應譜(Response Spectra)，透過反應譜的分析，我們更可以知道在不同阻尼比下的系統反應是如何。

The thesis is to investigate the responses of hi-tech factory structure to the ambient vibrations. First, the author employed the ambient instrument (spc-51) to measure the speed data in time domain and subsequently transferred it to frequency domain through Fast Fourier Transform. The speed data were takes twice at gym field of National Chiao-Tung University at different dates. Affer the data were taken, the values of one-third octave band were calculated in order to understand the magnitude of ambient vibrations. Secondly, the author calculated the absolute acceleration, absolute speed and absolute displacement responses of a single-degree-of-freedom system through equations of motion. Then Response Spectra of the ambient vibration with different damping ratios were calculated in order to shed some light on the amplification of the vibrations due to structural system.