【作者】 邢燕好；

【导师】 杨理践；

【作者基本信息】 沈阳工业大学 ， 测试计量技术及仪器， 2019， 博士

【摘要】 压力管道广泛应用于石油化工、电站、军工等能源行业领域,因其工作环境极为恶劣,长期工作在高温、高压、易腐蚀等环境下,受各种外力作用或自身制造工艺原因致使裂纹产生不可避免,进而影响管道的安全运行。因此,管道裂纹检测对管道安全评价具有重要意义。根据裂纹的走向角度,管道裂纹可以分为轴向裂纹、周向裂纹和斜向裂纹。裂纹检测有超声导波、漏磁、弹性波等多种技术方法,其中超声导波法是裂纹检测的主要技术之一。目前,国内外管道裂纹检测超声导波法主要采用周向导波和轴向导波,分别实现轴向、周向裂纹检测。在进行管道检测过程中,超声波遇到斜裂纹缺陷时,反射超声波主声束的传播方向不再沿管道的轴向和周向,而沿管道的螺旋方向传播,即为管道螺旋导波。受超声波声场指向性的制约,轴向和周向探头无法较好接收到主声束沿着螺旋方向传播的超声导波。论文针对螺旋导波技术进行管道裂纹检测的问题,开展了理论、仿真、设计、实验等大量的研究工作,取得了部分新颖性的研究成果。论文对螺旋超声导波进行了数理描述,推导了螺旋导波主声束的传播方程。针对螺旋导波接收的技术难点,论文研究了管道螺旋超声导波的理论基础,通过对固体形变时体元的应力和应变分析,结合固体介质的弹性性质和弹性系数,描述了各向同性固体介质的声波方程;通过对管道中周向导波和轴向导波理论研究,结合扭转波的理论基础,对管道螺旋超声导波进行了数学描述;通过对其柱坐标系下的三维管道柱面展开成二维平面,进行了管道平面解析分析,推导了平面内螺旋波检测周向缺陷、轴向缺陷、一般斜向缺陷时的传播方程,包含发射波、反射波等螺旋波的声束主轴线的传播方程。提出了超声导波多模态分析的螺旋导波的分析方法。论文研究了电磁超声换能器导波传播方向分析和三维管道中电磁超声螺旋导波传播方向控制理论。论文在管道螺旋超声导波理论研究的基础上,详述了非接触式电磁超声的换能原理,并对电磁超声换能器的电磁学理论基础和机械力理论基础进行了阐述。非铁磁性材料中,电磁超声换能机理为洛伦兹力机理;铁磁性材料中电磁超声换能机理为磁化力机理、磁致伸缩力机理、洛伦兹力机理。论文基于毕奥-萨伐尔定律对静磁学中电流元在空间中产生的磁场分布理论,提出了电磁超声换能器导波传播方向分析模型,通过对瞬时等效通电闭合线圈产生的磁场分布进行数学计算分析,得出垂直于工作导线方向为磁场分布最大;垂直距相等时,在工作导线的中垂线方向其磁场分布最大;建立了三维管道中电磁超声螺旋导波传播方向控制模型,分析得出换能器线圈螺旋角度改变可以实现控制螺旋导波主声束的传播方向。论文研究了解析平面内电磁超声换能器的建模仿真,对电磁超声换能器的磁场、涡电流场、洛伦兹力等进行解析,设计了斜向曲折型线圈结构,并采用柔性FPC线圈设计制作了应用于管道检测的电磁超声螺旋导波换能器。本文在基于电磁超声换能器的理论分析和仿真分析基础上,提出并设计了一种电磁超声螺旋导波换能器,研究了换能器线圈夹角与螺旋导波升角的关系。当电磁超声螺旋导波换能器工作时,根据法拉第电磁感应定律,通有高频大功率激励电流的换能器线圈在钢管内部感应出沿螺旋方向的交变磁场,在永磁体的静态偏置磁场作用下,钢管表面及近表面会受力产生周期性收缩和拉伸变化,从而带动管道中质点形成高频振动,该高频振动沿着管道的螺旋方向以超声波的形式传播出去,形成了电磁超声螺旋导波。本文针对电磁超声管道螺旋导波内外检测方法和径向、轴向偏置磁场形式设计了四种应用于管道检测的电磁超声螺旋导波换能器。论文针对设计的能产生和接收螺旋导波的电磁超声换能器,进行了螺旋超声导波的传播功能验证实验和螺旋波的声场指向性实验等,实验研究了电磁超声管道螺旋导波的传播机理。论文针对样管上的周向槽缺陷进行了检测对比实验,当电磁超声螺旋导波换能器的激励线圈斜率变化时,不同的升角的螺旋导波接收回波时间不同;对分布在周向不同时钟位置的周向槽均能接收到回波,验证了螺旋导波电磁超声换能器的正确性。研究结果表明,螺旋导波可用于管道裂纹检测;电磁超声螺旋导波换能器线圈的升角不同,可以产生和接收不同升角的螺旋导波;螺旋导波的升角越大,螺旋导波速度沿轴向传播越快;螺旋导波的升角越小,螺旋导波速度沿轴向传播越慢,多模态导波的分离越清晰;小角度升角参数的螺旋导波具有回波多模态分析的显微镜功能。论文研究了电磁超声螺旋导波管道检测的轴向定位与缺陷斜向角计算方法。针对管道周向、轴向缺陷及斜向缺陷检测的设计目标,论文提出了两种电磁超声管道检测系统方案设计,利用回波信号的动、静态回波时间参数、幅值参数及收、发换能器线圈升角参数和管道参数等,推导了管道轴向定位坐标的计算方程。回波信号的动、静态回波时间值、幅值等是缺陷检测轴向定位的关键参数。论文通过对螺旋导波的理论计算、电磁超声换能器建模仿真、实验验证了管道螺旋导波的传播和管道周向和轴向缺陷检测的可行性,实现了一种新颖的管道缺陷检测技术的探究。更多还原

【Abstract】 Pressure pipeline is widely used in petrochemical,power stations,military industry,and other areas of the energy industry,because of its long-term work in harsh environments such as high temperature,great pressure,area easy to corrode,it is inevitable to cause crack by various external forces or itself reason during the manufacturing process,which will affect the safe operation of the pipeline.Therefore,pipeline crack detection is of great significance for pipeline safety evaluation.Cracks can be divided into longitudinal crack,circumferential crack and oblique crack according to the crack direction of pipeline.The crack detection includes ultrasonic wave,magnetic flux,elastic wave and other technical methods,including ultrasonic wave method,which is one of the main techniques of crack detection.At present,the ultrasonic wave method of pipe crack detection at home and abroad mainly uses the circumferential guide wave and the longitudinal guide wave to realize the longitudinal and circumferential crack detection respectively.During the detection of the oblique crack in the pipeline,the direction of the reflection ultrasonic acoustic beam is not propagated along the longitudinal and circumferential direction of the pipe,and the spiral direction of the pipe is propagated in the direction of the pipe helix.For the reason of ultrasonic wave direction,the traditional guided wave receiving probe can not receive the ultrasonic wave propagating in the direction of the main acoustic beam.Aiming at the problem of spiral guided wave technology in pipeline crack detection,a lot of research work has been carried out in theory,simulation,design and experiment,and some novel research results have been achieved.In this paper,the basic concept and mathematical description of helical guide wave are presented and the propagation equation of the spiral guide wave is derived.For the receiving technical difficulties of the helical guide wave,this paper studied the theory foundation of the ultrasonic guided wave in the spiral pipe.By analyzing stress and strain elements during the solid deformation,the author combined the elastic properties of solid medium and elastic coefficient,and described the isotropic solid medium of the acoustic wave equation.Based on the theoretical study of circumferential guided wave and longitudinal guided wave in pipeline and the theoretical basis of torsional wave,the mathematical description of helical guided wave in pipeline is given.Through the cylindrical coordinate system,the three-dimensional cylinder surface is expanded into two dimensional plane,analytical analysis of pipeline plane is carried out.The propagation equation of helical wave in plane for circumferential defect,longitudinal defect and general oblique defect detection is deduced,including the propagation equation of the main axis of the helical wave beam,such as transmitting wave and reflecting wave.A method of spiral guided wave analysis for ultrasonic guided wave multimodal analysis is proposed in this paper.In this paper,the analysis of guided wave propagation direction of electromagnetic ultrasonic transducer and the control theory of guided wave propagation direction of electromagnetic ultrasonic helical wave in three-dimensional pipeline are studied.Based on the theoretical study of helical guided wave in pipeline,this paper elaborates the principle of non-contact electromagnetic ultrasonic energy transfer,and expounds the electromagnetic and mechanical theoretical basis of electromagnetic ultrasonic transducer.The magnetic field,eddy current field and Lorentz force of the electromagnetic ultrasonic transducer are analyzed by establishing the simulation model of the analytic plane electromagnetic ultrasonic transducer.In non-ferromagnetic materials,the mechanism of electromagnetic ultrasonic energy transfer is Lorentz force mechanism,in ferromagnetic materials,the mechanism of electromagnetic ultrasonic energy transfer are magnetization force mechanism,magnetostrictive force mechanism and Lorentz force mechanism.Based on Biot-Savar’s law,the magnetic field distribution theory of current elements in space in magnetostatics is proposed,the analysis model of guided wave propagation direction of electromagnetic ultrasonic transducer is proposed.Through the mathematical calculation and analysis of the magnetic field distribution generated by the instantaneous equivalent energization closing coil,it is found that the magnetic field distribution is the largest in the direction perpendicular to the working wire.When the vertical distance is equal,the magnetic field distribution is the largest in the direction of the vertical line of the working wire.A control model of the propagation direction of electromagnetic-ultrasonic helical guided wave in three-dimensional pipeline is established.It is concluded that the transmission direction of the main beam of helical guided wave can be controlled by changing the helical angle of the transducer coil.In this paper,the simulation of electromagnetic ultrasonic transducer in analytical plane is studied.The magnetic field,eddy current field and Lorentz force of electromagnetic ultrasonic transducer are analyzed.The structure of oblique winding coil is designed,and the electromagnetic ultrasonic spiral guided wave transducer used in pipeline detection isdesigned and manufactured by using flexible FPC coil.Based on the theoretical analysis and simulation analysis of the electromagnetic ultrasonic transducer,this paper presents and designs an electromagnetic ultrasonic spiral guided wave transducer,and studies the relationship between the coil angle of the transducer and the spiral guided wave elevation angle.According to Faraday’s law of electromagnetic induction,when the electromagnetic ultrasonic spiral guided wave transducer works,the coil of the transducer with high frequency and high power exciting current induces alternating magnetic field along the spiral direction inside the steel pipe.Under the static bias magnetic field of permanent magnet,the surface and near surface of steel pipe will undergo periodic contraction and tension changes,thus driving the particles in the pipe to form high-frequency vibration.The high frequency vibration propagates in the form of ultrasonic along the spiral direction of the pipeline,forming electromagnetic ultrasonic spiral guided wave.In this paper,four kinds of electromagnetic ultrasonic spiral guided wave transducers for pipeline detection are designed according to the internal and external detection methods of spiral guided wave and the radial and longitudinal biased magnetic fields.Aiming at the design of electromagnetic ultrasonic transducer which generates and receives spiral guided waves,the experiment of verifying the propagation function of spiral guided waves and the experiment of directivity of the sound field of spiral waves are carried out,the propagation mechanism of spiral guided waves in electromagnetic ultrasonic pipeline is experimentally studied.In this paper,the comparison test is carried out for circumferential groove defects on sample pipe.The receiving time of the spiral guided wave with different elevation angles is different when the slope of the excitation coil of the electromagnetic ultrasonic spiral guided wave transducer changes.The echoes can be received by the circumferential grooves distributed at different clock positions in the circumferential direction,which verifies the correctness of the spiral guided wave electromagnetic ultrasonic transducer.The results show that the spiral guided wave can be used for pipeline crack detection,the spiral guided waves with different elevation angles can be generated and received by the coils of the electromagnetic ultrasonic spiral guided wave transducer,the greater the helix angle of the spiral guided wave,the faster the propagation velocity of the guided wave along the longitudinal direction,the smaller the spiral angle of helical guided wave is,the slower the velocity of helical guided wave propagates along the longitudinal direction,and the clearer the separation of multi-mode guided wave is,the helixguided wave with small angle angle parameters has the function of echo multimodal analysis.In this paper,the calculation methods of longitudinal location and oblique angle of defects in electromagnetic ultrasonic spiral guided wave pipeline inspection are studied.Aiming at the design target of pipeline circumferential,longitudinal and oblique defect detection,two schemes of electromagnetic ultrasonic pipeline detection system are proposed in this paper.Based on the dynamic and static echo time parameters,amplitude parameters,receiving and receiving parameters,spiral angle parameters of transducer coil and pipeline parameters of echo signal,the calculation equation of pipeline longitudinal positioning coordinates is deduced.The dynamic and static echo time value and amplitude of echo signal are the key parameters for longitudinal location of defect detection.Through theoretical calculation of spiral guided wave,modeling and Simulation of electromagnetic ultrasonic transducer and experiment,the feasibility of spiral guided wave propagation and pipeline circumferential and longitudinal defect detection is verified,and a new pipeline defect detection technology is explored.更多还原