Finite Element Simulation Of Pipeline Defects Quantitative Methods To Improve Research

Pipeline system is widely used in metallurgy, petroleum,chemical industry and urban plumbing supply industrial sectors. Because of industrial pipes working conditions are bad, prone to corrosion, fatigue damage or to defects in the development pipeline of potential internal damage caused by leakage.In particular, ferromagnetic oil and gas pipelines due to a long period of corrosion,wear and tear or accidental mechanical damage and other reasons will form a variety of defects[12]. Failure to discover and to make repairs, will eventually lead to pipe media leak, causing all kinds of pipeline accidents. A comprehensive understanding of pipeline corrosion, damaged condition,as much as possible against the risk of vulnerabilities in a timely manner for processing, to prevent a pipeline spill incidents, or to minimize losses caused by the accident. We must take advantage of pipeline inspection device on a regular basis pipeline inspection. The timely detection of pipeline defects and to obtain its location, type, geometry and so on accurate information, so as to pipeline safety evaluation, life prediction, and so provide a reliable basis for repair and maintenance[7]. Therefore, pipeline monitoring and diagnosis of non-des(?)uctive testing technology has become an important aspect.Inner surface pipeline detection is an important means of flaw detection, and to ensure the safe operation of pipelines play an important role. Magnetic flux leakage pipe inspection is divided inner surface flaw detection and surface flaw detection, in which magnetic flux leakage flaw detection applications is especially widespread in China. Flaws in the service with Gas Pipeline Magnetic Flux Leakage detection technology research, to gain a relatively accurate pipeline flaws characteristic parameters for the quantitative evaluation of pipeline flaws of the residual strength of the defect to provide reliable data. In this paper, magnetic; flux leakage (Magnetic Flux Leakage, referred to as MFL, the magnetic flux leakage) principle as the basis, by solving Maxwell's equations numerical finite element method is applied to establish defect leakage magnetic field model as the core, mainly from the following aspects of exposition and research.a. Briefly discusses the development of domestic and international pipeline and the status quo, as a transport carrier of its incomparable superiority. b. Introducing the common types of pipeline accidents-spills, identify the safe operation of gas pipelines and present danger of harmful factors.c. Analysis of urban buried gas pipeline laying the characteristics of an attempt to reveal the laws of pipeline accidents, leads to the need for pipeline leak detection.d. Summary of Pipeline non-destructive testing methods, and a careful analysis of the pipeline than the magnetic flux leakage flaw detection and ultrasonic testing, magnetic flux leakage testing at home and abroad brief technology development.e. Introduced the Gas Pipeline Magnetic Flux Leakage Detection System development and on-line monitoring devices, mechanical structure, working principle and the characteristics of the composition of the system.f. Sets out the basic theory of electromagnetic fields and the iron magnetic material produced by magnetic flux leakage defect mechanism, detailed discussion MFL detection principle.g. Leakage magnetic field analysis method to explore and compare the dipole model approach and the finite element model approach the advantages and disadvantages, by solving the Maxwell equation,finite element model of the magnetic field leakage defects.h. An overview of the basic theory of finite element simulation and problem-solving steps, obtained by inversion of the signal parameters and magnetic flux leakage defect feature the relationship between the analytical model simulation of signals generated by the error correction method and explore.i. An outline of the finite element simulation software-ANSYS, and the establishment of Pipeline Magnetic Flux Leakage Inspection model, and rely on computer simulation, using finite element simulation of the test data processed by magnetic flux leakage defect cloud.j. Respectively on the defects of different length, width and depth of the finite element simulation, the corresponding leakage magnetic cloud and the axial and radial component waveform to study the defects of geometric parameters of the relationship between magnetic flux leakage signal and change the corresponding law.k. Illustrate the detection method deficiencies and improve the outlook, and to explore the direction for further research and put forward ideas pipeline defects grading.