| FRP tank was widely applied to oil and gas,storage,transportation and sewage treatment,etc due to advantages of reliable quality,security and stability.However,the impact resistance of glass fiber reinforced plastic composite materials was poor,which lead to crack and layering and serious economic losses.Therefore,the safety inspection was necessary in the process of application.At present,glass fiber reinforced plastic storage tanks acoustic emission source localization testing research were relatively few because of the characteristics of wave signal attenuation fast and spread with anisotropy.Therefore the topic that acoustic propagation characteristics of glass fiber reinforced plastic material characteristics and sound source localization research is of great significancThis topic first design and processing the glass fiber composite material plate and glass fiber reinforced plastic tank specimen.Through glass fiber composite material plate and glass fiber reinforced plastic tank off the lead test for acoustic emission signal propagation are studied,the acoustic emission signal velocity and attenuation law in the glass fiber materials were got.And through the polynomial fitting Angle,velocity polynomial are obtained.To effectively reduce the positioning error,acoustic emission wave propagation in the glass fiber composites frequency change law were analyzed.Combining the theory of modal acoustic emission method of acoustic emission wave arrival time for study,research shows that FRP acoustic emission source localization using low frequency band pass filter(bandpass range from 20 to 70 KHZ)can decrease the positioning error.On the basis of glass fiber reinforced plastic storage tank wall of the acoustic emission signal propagation characteristics,Two kinds of sensor layout were determined of the the same wall thickness and different wall thickness.Three probes fiberglass tank wall location model was established.In addition,the FRP tank bottom acoustic emission signal propagation path was determined t and the final bottom ae source location model was established.The BP neural network was established based on the BP neural network for FRP acoustic emission signal analysis and research into the pattern recognition for the realization of the acoustic emission signal clustering.Acoustic emission signals fast recognition and fusion were achieved combining time determination criterion and BP network.Acoustic emission source positioning software was programmed based on MATLAB.And the fiberglass tank wall and bottom plate positioning test verified the effectiveness of the localization model and the feasibility of software.Fast effective detection method was provided for glass fiber reinforced plastic storage tanks. |
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