TIME-FREQUENCY CHARACTER-ISTIC OF BLAST VIBRATION SIGNATHREE-DIMENSIONAL FRACTAL STUDY ON THE L
XIE Quan-min1, 2; LONG Yuan1; TIAN Zuo-wei3; ZHANG Yang-yi1; JI Chong1
1. Engineering Institute of Engineering Corps, University of Science & Technology of PLA,Nanjing 210007, China; 2. 63988 Troops,PLA.,Jincheng 048000,China; 3. Institute of Sciences, PLAUST, Nanjing 211101, China
Abstract:To further study the characteristics of blast vibration signals, time-frequency energy character-istics of blast vibration signals were analyzed based on wavelet packet transform. The three-dimensional fractal surface box dimension model was established based on two-dimensional rectangular box covering method. By analyzing the measured blasting vibration signal data, fractal dimension of the three-dimensional time-frequency energy spectrum is 2.1488, which meets the condition for space fractal dimen-sion , and verifies that the time-frequency energy spectrums of blasting vibration signals have fractal characteristics. By studying the relationship between the three-dimensional fractal surface and two-dimensional box dimension of its section, the assumption of for traditional surface fractal dimension calculation method is not exactly. The study indicates, cuboids’ covering surface calcula-tion method for fractal dimension is feasible and effective, which provides a new idea for further study of blast vibration characteristics and the blasting seismic effect control.