对岩石试件加载及破坏过程进行了声发射试验,根据参数分析法得到Kaiser点。采用FFT研究了Kaiser点信号的频谱特征。运用小波包分析方法,计算了Kaiser点信号的能谱系数。用混沌时序分析方法研究Kaiser点信号,运用关联积分法方法提取关联维数D,综合FNN法和互信息法得到合适的m、τ值重构相空间,计算Kaiser点信号的最大Lyapunov指数,研究声发射信号混沌动力特征。结果表明,Kaiser点信号具有混沌特征。
Acoustic emission in sandstone specimens are tested under loading and breakage,Kaiser point is determined by parameter analysis method. The frequency spectrum characteristics of Kaiser point signal are obtained by using the fast Fourier transform(FFT). The energy spectrum coefficients of Kaiser point signal are calculated by means of wavelet packet analysis method. The Kaiser point signals are studied by applying the chaotic time series analysis method,and correlation integral method is used to gain correlation dimension D; then the maximum Lyapunov exponent is calculated by reconstructing phase space with adaptable parameters m,τ that are obtained through the false nearest neighbors(FNN) method and mutual information method. The results show that the Kaiser point signals have chaotic characteristics.