Coal impact damage SHPB testing signal de-noising based on HI-IT method

Abstract：According to Split Hopkinson Pressure Bar (SHPB) test signal characteristic with high noise, short lasting time,mutant fast,the Hilbert-Huang transform (HHT) analysis technique was used to de-noise testing signal on the coal impact failure. The intrinsic mode function (IMF) components and its' frequency spectrum and the energy per- centages of IMF components were got by using empirical mode decomposition (EMD) decomposition to measure coal impact damage SHPB test signal. Thus the high frequency noises were effectively separated out from the original signal by the low-pass filtering. Through the comparison of original signal and de-noised signal characteristic by using fast Fourier transform (FFT) spectrum and Morlet spectrum analysis, the qualitative conclusion that the HHT method could be used in coal impact damage SHPB testing signal de-noising were obtained. From the calculation of the de- noised signal noise ratios and energy percentages, it was indicated that the de-noised signals were fully retained the signals' transient non-stationary featured and the de-noising effect was obvious by HHT method in quantitative de- scription. The HHT method,which is applied for coal impact damage SHPB testing signal de-noising, is simple and can obtain reliable results.