近场地震动加速度脉冲的小波变换识别

Identification of Acceleration Pulses of Near-Fault Earthquake Ground Motion by Wavelet

近场加速度脉冲很早就被人们观察到,由于其对结构的不利影响,多年来一直为不少研究者所关注。以往的研究者多从速度脉冲的研究入手,近来有学者直接分析加速度脉冲,比如利用EMD分解来得到高频和低频的加速度脉冲。利用小波变换来分解加速度时程,得到其高频和低频分量,并从中识别加速度脉冲。通过从反应谱和结构非线性响应两个方面的对比,证明了小波分解的可靠性,从而保证了识别的加速度脉冲的准确性。

Acceleration pulses have been found in near-fault earthquake ground motions long ago and attracted lots of researchers, since such pulses, especially low frequency pulses have great impact on engineering structures. Many people previously focused on velocity pulses which result from acceleration pulses, however, recently a few researchers began to directly study acceleration pulses, such as to get high frequency pulses and low frequency pulses with empirical mode decomposition. Wavelet transform was utilized to decompose acceleration records. Subsequently high frequency and low frequency components of the records were obtained and acceleration pulses were identified. By comparisons in response spectra and structural nonlinear responses, it is proved that the decomposition of acceleration records with wavelet is reliable and the identification of acceleration pulses is correct.