Damage Identification Analysis And Experimental Validation Of Pipeline Structures Using Piezoelectric Element

At present,the application of pipeline structure in the production and life of our country is more and more extensive.By virtue of its low cost,large capacity,high efficiency,less pollution,pipeline transportation has played an important role in the economic construction and industrial development in the world.However,due to the special transported material,long service time and complex working environment,the pipeline structure will inevitably produce crack,corrosion and other forms of defects.Pipeline structure damage,there may cause the pipeline leak or even explosion accident,which will bring immeasurable loss to people's lives and property safety,the national economy and the natural environment.Therefore,it is necessary to carry out proper health monitoring for pipeline structure.In the field of structural health monitoring,ultrasonic guided wave detection technology based on piezoelectric ceramics is getting more and more attention because of its low cost,fast response,easy operation and so on.Nowadays the research on the simulation of pipeline structure detection by using finite element software is becoming a hot method.But in most of the simulations,the health status of pipeline structure is analyzed by using the displacement signal of excitation and reception,which have a great difference with the method of excitation and receiving electrical signals by the piezoelectric effect of the piezoelectric patch in the actual test.And at present,the energy method is mostly used to analyze the damage of pipeline structure,which lack of the study about damage identification of pipeline structure.In this paper,using the method of theoretical analysis,numerical simulation and experimental verification of the combination,proposed a pipeline structural damage identification detection method based on piezoelectric element,and the corresponding experimental verification is performed on an aluminum plate structure and a steel pipeline structure.Firstly,based on the previous researc,the propagation characteristics of guided waves in hollow circular tubes are analyzed theoretically,and the dispersion equation of cylindrical and circumferential guided waves is derived.The Matlab software is used to numerically solve the dispersion equation of guided wave and the group velocity and phase velocity dispersion curve of the corresponding size of the pipeline are plotted.Through the frequency dispersion curve and the analysis of the multi modal phenomena of guided wave propagation in the pipeline,the excitation frequency of ultrasonic guided waves in the simulation and experiment are determined.Secondly,the finite element method is used to simulate the pipeline structure of the health state and the damage state and research on damage localization and identification by using the ABAQUS finite element software.In order to verify the effectiveness of the proposed piezoelectricelement model,the confirmatory simulation and experiment of damage detection using aluminumplate structure are carried out.Finally,the damage identification of pipeline structures using ultrasonic guided waves is verified by experiments.The 5 periodic sine signal modulated by the Hanning window function is selected as the test excitation signal.The intelligent material piezoelectric ceramic is used as the excitation and receiving device of the signal to establish a set of effective and convenient test system.Through the test method,the damage detection of the nondestructive pipe and the destructive pipe is carried out respectively.By comparing the simulation results with the experimental results,it is concluded that the two methods are basically consistent,which verifies the feasibility and accuracy of the numerical simulation and test methods.