Analysis And Research Of Wire Rope Damage Signal Based On Non-destructive Testing Technology

Wire rope is widely used in industrial production because of its advantages such as light weight,good elasticity,high tensile strength and strong bearing capacity.However,as a key part of the wire rope,damage will inevitably occur in the process of work,which has a potential threat to the safety of production.Therefore,the inspection and accurate identification of wire rope damage is of great significance to the stability of economy and society.Based on the nondestructive testing technology,this paper carries out theoretical analysis and experimental verification on the qualitative and quantitative detection of wire rope damage.The main research contents are as follows:Firstly,the structure of wire rope and several main types of defects are introduced,and the characteristics and causes of different defects are analyzed.Based on the structural characteristics of steel wire rope,the magnetic field leakage detection method in nondestructive testing is adopted to distinguish the damage of steel wire rope.The advantages of this method are as follows:low cost,mature technology and stable detection results,and it can be widely used in harsh environments.In addition,the overall framework of wire rope magnetic flux leakage detection system is introduced:(1)The hardware design and implementation of magnetic flux leakage detection probe are introduced,and the design and working principle of Hall element inside the probe are analyzed emphatic;(2)Improve the traditional data processing system based on PC platform and adopt the data processing system based on embedded platform to make data collection more convenient.Secondly,the sampled signal is preprocessed in time domain and denoised in frequency domain.The components of wire rope damage signals are analyzed.The time domain and frequency domain methods are used to remove background noise and interference for different signal components.Time-domain preprocessing includes eliminating singular values and de-trending items.Data processing in the time domain reduces the complicated operation of data conversion to the change domain and lowers the hardware standard of data processing.According to the characteristics of the wire rope damage non-stationary signal,frequency domain denoising method of wavelet analysis,and on the basis of the traditional thresholding function put forward an improved weighted average algorithm,this algorithm according to the characteristics of steel wire rope broken wires signal adaptively change the size,weight,in turn,change the size of the threshold,thus optimize the denoising effect.Both theoretical analysis and experimental results show that the denoising effect of the proposed algorithm is better than that of the traditional threshold function.Then,the paper studies the signal identification and feature extraction of the broken wire damage of the wire rope,and finally realizes the quantitative identification.On the basis of the deviation analysis,the adaptive threshold deviation analysis is proposed to improve the resolution of broken wire damage in the harsh detection environment.For the feature extraction of broken wires,it is proposed to combine the wavelet energy,the temporal frequency domain feature,with the traditional time-domain feature,to form the characteristic value data set of broken wires damage.The MATLAB CFTOOL(Curve Fiting Tool)Tool box is used to carry out data Fitting on the characteristic value samples to verify the characteristic law that the characteristic value changes with the increase of the number of broken wires.To realize the quantitative identification of broken wire.The proposed eigenvalue data set improves the accuracy and reliability of quantitative identification of broken wiresFinally,the damage of wire rope cross-sectional area is analyzed quantitatively.The finite element simulation model was established to obtain the change rule of magnetic field leakage on the surface of wire rope with the change of metal cross-sectional area loss,and it was verified that the peak value of magnetic field leakage was the main feature to judge the damage of cross-sectional area.Matlab fitting tool is used to obtain the conclusion that the peak value of magnetic flux density of wire rope surface leakage field is linearly related to the cross-sectional area loss,and the correctness of this conclusion is verified by experiments.