Research On Monitoring Glass Quality Of Laser Induced Thermal Cutting Based On AE Technology

As the glass cutting quality demands higher in various fields, technology of laserinduced thermal fracture cutting has great advantages compared with the traditionalcutting method, but the crack propagation trajectory deviates from the desirable path.Path compensation can improve the deviation, but it needs the crack propagationstates in real time. As a non-destructive testing method, acoustic emission(AE) hasexcellent potential on the real-time monitoring.The work has carried out depth study on the real-time monitoring of the crackpropagation states including AE source location.Firstly, the signal processing methods were confirmed, which includes parameteranalysis, wavelet analysis, time-frequency analysis and modal analysis. The rationalparameters of the wavelet packet analysis were determined based on the calculateddispersion curve of glass. In the meanwhile, the reasonable time-frequency analysismethods were also confirmed. The above analysis can provide a theoretical basis forthe select of experimental signal processing.Secondly, the factors of AE source localization accuracy were found by planeTDOA location algorithm, which include shape factor Q and measure factor H. Theexperimental system was set up after optimizing arrangement of the sensor based onQ and selecting AE instrument based on H.Finally, the crack propagation monitoring experiments was conducted. AE signalcharacteristics were extracted in time and frequency domain. Through MagnitudeChart and Energy-Amplitude Figure, the various stages of the crack propagation wereidentified. By the time-frequency analysis of crack fault signal obtained by twosensors in the same position on both sides, the installation of sensors was confirmed.Using the TDOA location method and SPWD time-frequency analysis method whichboth combined plate wave theory, the defects were located. Through the analysis ofpositioning error, the corresponding improvement measures were given.The study shows that acoustic emission technique can accurately monitor thestates of crack, which can provide technical support for the compensation method. Sothrough the study, it can improve the quality of glass cutting ultimately.