Physic perspective fusion of electromagnetic acoustic transducer and pulsed eddy current testing in non-destructive testing system

Abstract

Comprehensive non-destructive testing (NDT) for pipelines is a critical and challenging task. This paper proposes a novel physic perspective fusion NDT method of electromagnetic acoustic transducer (EMAT) and pulsed Eddy current testing (PECT) for detecting hybrid defects. This transceiver-integrated fusion sensor structure can simultaneously excite ultrasound and pulsed eddy current. Therefore, the generated ultrasound is applied to detect deep defects, while the eddy current detects surface defects. The theoretical derivation of EMAT and PECT fusion mechanism has been developed for analysis and interpretation of the results. In addition, numerical simulation on the detection of hybrid defects including surface defects with different width, depth and multiple bottom-thinning defects has been conducted. Experiments on both ferromagnetic and non-ferromagnetic material verify the feasibility of composite detection. Finally, tests have been validated on pipeline with weld defects, and the results show that the composite inspection method is capable of monitoring thickness variations and inspecting surface defects. This article is part of the theme issue ‘Advanced electromagnetic non-destructive evaluation and smart monitoring’.

A Systematic Review of Advanced Sensor Technologies for Non-Destructive Testing and Structural Health Monitoring

“…An example of an advanced technique is phased array ultrasonic testing (PAUT), whereas straight beam ultrasonic testing (UT) [ 102 ] is considered a conventional technology that has matured over many decades and is widely being applied. Other examples of advanced NDT methods are Laser Profilometry [ 76 ], Alternating Current Field Measurement [ 103 ], Angle Beam [ 104 ], Automated Ultrasonic Backscatter Technique (AUBT) [ 105 ], Holographic Testing [ 106 ], Laser Shearography [ 107 ], Computed Tomography (CT) [ 108 ], Digital Radiography (DR) [ 109 ], Computed Radiography (CR) [ 110 ], Electromagnetic Acoustic Transducer (EMAT) [ 111 ], Time-of-Flight-Diffraction (TOFD) [ 112 ], Immersion Testing [ 113 ], Long Range Ultrasonic Testing (LRUT) [ 114 ], Internal Rotary Inspection System (IRIS) [ 115 ], and Phased Array Ultrasonic Testing (PAUT) [ 116 ].…”

Pipeline In-Line Inspection Method, Instrumentation and Data Management

“…For example, conductive materials inspection through ET is useful for near-surface defect detection whereas UT yields volumetric information. Employing both methods and integrating them in the same sensor, the multiple characteristic signals will directly generate from the system to better cover the surface and deep defects [ 199 ]. Robotic and instrumental challenge of speed effect and robustness and adaptivity for varied environments …”

Structural Coupled Electromagnetic Sensing of Defects Diagnostic System

“…Li et al [18] proposed a structure of magnetic sensors array based on ACFM probe, which is adequate to detect defects with narrow string flaws of ferrimagnetic materials. Guo et al [19] presented a novel physics perspective fusion of EMAT and eddy current testing (EC) which is capable of inspecting near-surface and internal defects of ferromagnetic and non-ferromagnetic material. Bang et al [20] proposed a new guided wave testing technology for pipeline defect detection.…”