基于小波变换的爆破振动时频特征分析

应用小波变换方法对短时非平稳爆破振动过程提出了时频特征分析。根据离散小波变换的分层分解展开关系，将爆破振动时间历史信号用分层重构信号进行扫描。应用这些信号可以给出不同频率带上爆破振动的相对能量分布和振动强度的时间变化规律。一个爆破振动实测结果的分析表明，与建立在传统Fourier变换基础上的频谱分析方法相比，基于小波变换的爆破振动时频特征分析可以给出更为准确的细节信息。文中的研究结果为爆破振动结构安全性分析提供了新的途径。

TIME-FREQUENCY CHARACTERISTIC ANALYSIS OF BLASTING VIBRATION BASED ON WAVELET TRANSFORM

The time-frequency process of blasting vibration is a nonstationary random one with short duration, and analysis is made on the process by means of wavelet transform technique. According to the multiresolution decomposition of discrete wavelet transform,the time history signal of blasting vibration may be expressed by different level reconstructed signals of wavelet decomposition. By using these signals,the relative energy distributions of blasting vibration in different frequency bands and the regularity of vibration strength varying with time can be obtained. Blasting vibration measurement shows that the time-frequency characteristic analysis based on wavelet transform yields more accurate information details of blasting vibration,compared with the frequency spectra analysis on the conventional Fourier transform. The suggested method provides a new approach for analyzing the structural safety under blasting vibration conditions.