Attenuation Characteristics of Stress Wave Propagation in a Polycarbonate Rod Using Wavelet Packet Analysis

In this paper, a method of wavelet packet decomposition and multi-frequency band analysis is considered to study the amplitude attenuation characteristics of stress wave propagation in a viscoelastic polycarbonate (PC) rod. The reconstruction coefficients of different frequency bands could be acquired through wavelet packet decomposition and reconstruction. Associate conjugate gradient method with modified Sadaovsk formula to fit the curve of peak amplitude for each frequency band, from which the amplitude attenuation characteristics and attenuation rates of each frequency band with the increasing of the propagation distance were obtained. Predicted the waveform in the light of viscoelastic attenuation behavior of different frequency bands, it gives better mean square error (MSE) compared with the actual waveform. This result indicated that this method can effectively predict the propagation disciplinarian of the viscoelastic stress wave.