ACOUSTIC EMISSION EVALUATION SYSTEMS OF TOOL LIFE FOR SHEARING OF PIANO AND STAINLESS STEEL WIRES
Masanori TAKUMA, Noboru Shinke, Takako Nishiura, Kensuke Akamatu · 2006
Shearing is a machining operation that separates the workpiece material by the growth of a crack, which occurs in the narrow region around the tool tip. It is necessary to evaluate the tool life because the product quality is influenced by the wear conditions of the tool. However, the problems for evaluating the condition and the tool life have not been solved yet. In this study, chaos time series analysis, wavelet transform and waveform analysis are applied for recognizing the characteristics of the detected AE signals in the shearing of piano and stainless steel wires. The results are as follow: (1) AE signals have the chaotic property, and the wear condition and the tool life will be evaluated by the largest Liapunov exponent and the correlation dimension; (2) the RA (rise time/amplitude) value of the time fluctuation waveform of the wavelet coefficient is an effective parameter for tool life prediction; (3) the validity of this system for the tool life by the RA value was confirmed by the comparison with the experimental results.