Acoustic Emission Signal Analysis And Damage Study Of Reinforced Concrete Beams

Acoustic emission technology is an efficient and time-saving new monitoring method that can issue safety warnings when the structure is about to undergo serious damage without interfering with its normal operation.This article designed and completed a bending load experiment on reinforced concrete beams.In order to complete the experiment,an 8-channel DS5 acoustic emission instrument was prepared to record the acoustic emission waveform signal data of reinforced concrete beams.Parameters were extracted from the waveform signal to analyze and study the acoustic emission waveform signal.At the same time,the extracted acoustic emission parameters were also analyzed and studied.A noise removal study was conducted on the acoustic emission signal of steel concrete structure damage.The complementary set empirical mode decomposition(CEEMD)and single channel blind source separation(SCBSS)methods were combined to remove noise from the simulated signal and the signal collected in the experiment.Other methods were then used to denoise the signal and compare their denoising effects.Applying Fourier decomposition(FDM)to time-frequency analysis of acoustic emission signals,and comparing it with other methods in time and frequency domains.Analyze and study the variation law of acoustic emission b value during the damage process of steel concrete specimens in experiments.The main research content is as follows:1.The joint method of complementary set empirical mode decomposition and single channel blind source separation is used to remove noise from the damage acoustic emission signal of reinforced concrete structures.Firstly,the complementary set empirical mode decomposition is used to decompose the noisy signal and obtain a series of modal components(IMFn).The dominant component is separated from the noise component using the correlation number,and the separated noise component is reconstructed to obtain a reconstructed signal.The reconstructed signal is combined with the original signal to form a multi-channel signal,and blind source separation is performed on this constructed signal to obtain a pure signal.2.The Fourier decomposition is applied to the HHT analysis,the acoustic emission signal time-frequency analysis,will get the corresponding time-frequency diagram.By comparing the diagram analyzed by this method with the diagram analyzed by other methods,the time-frequency resolution effect is observed and analyzed.Then,this method is applied to the time-frequency analysis of the acoustic emission signal collected in this thesis,and the effect is observed and analyzed.3.The bending experiment of reinforced concrete beam is designed and completed,and the variation law of acoustic emission b value during the experimental loading process is studied and analyzed.