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The development of automated NDT is more and more fast, in order to better serve the needs of NDT, we independently research robot system facing to the test, and achieve it's preliminary application. Basing on MOTOMAN-MH6 six degrees of freedom robot, this paper sets up “computer + PMAC + manipulation motor” motion control system, achieves to three closed-loop system in order to meet the exact requirements...
Probability of detection (POD) for defects under given test conditions is an important statistical technique for the detection reliability assessment. In this study, we investigate a set of 45 steel specimens with fatigue cracks in different lengths. Experimental results show that the increase of the crack length will enhance the crack heating response, and the logarithmic relationship between the...
This paper introduces a novel nondestructive testing (NDT) method based on laser ultrasonic technology and fiber Bragg grating (FBG) sensors. A FBG sensor is employed as discrete sensing elements to detect the ultrasonic generated by pulsed laser. An all-fiber and adaptive acousto-ultrasonic (AU) monitoring system for the dynamic detection of impact damage is developed for the present work. A tunable...
When the solid axle is detected by the conventional ultrasonic probes, the inspecting coverage of axle is very limited, especially for the press-fit part of axle where the signal-to-noise ratio of detection is very low, and the echoes are difficult to distinguish, which easily leads to false judgment or missing judgment. In view of this phenomenon, a kind of dedicated phased array ultrasonic probe...
The cast austenitic stainless steel (CASS) is hard to be detected using general ultrasonic methods on account of the low signal to noise ratio (SNR) caused by coarse-grained structure. A numerical model based on electron backscattered diffraction (EBSD) was established to simulate the phased array ultrasonic imaging of CASS. Aiming to enhance SNR, the phase coherence imaging (PCI) technique was implemented...
For non-destructive testing (NDT) to be applicable in mechanical equipment, it is mandatory that NDT is highly flexible, accurate and robust. At present there have been several methods based on acoustic, optical and electromagnetic information to detect the cracks of the mechanical equipment. As a new technology, the fusion of testing information harnesses the advantages of various NDT instruments,...
The focal law of linear phased array ultrasonic testing of carbon fiber reinforced plastic (CFRP) laminates was studied based on finite element modeling. Two stacking sequences, [0]40 and [45/90/-45/0]10, were considered and the focusing results were compared based on the calculation of transient acoustic field. It was found that the actual focal point was ahead of the preset location when the focal...
Radiation thermometry is one of the most important technical means in routine temperature patrol of critical component identification(CCI) in nuclear power plant(NPP). Based on the status of complicated thermometry environment, and measurement process being difficult to reach ideal state, this paper focuses on the theory and experiment analysis of emissivity on measured surface, thermometry distance,...
It is of some advantages for non-destructive testing surface and internal flaws using EC/EMA dual probe. The fusion detection principle of EMA/EC is emulated by finite element method. Aimed to EC, the current eddy field distribution focused on skin and coil impedance variation induced by eddy field is studied by theory and experiment method, and aimed to EMAT, the propagation characteristics of the...
Rail is a main part of railway track. Its reliability relates to the national economy and people's livelihood. The fracture of rail will lead to disastrous consequences. This article mainly introduces the residual stress of rail detection and regulation technology, completes the relevant tensile experiments and rail experiments, analyses the results and the function of regulation. Eventually, an effective...
This article introduced the basic principle of acoustic emission technology and its characteristics. It summarized the applications of acoustic emission technology in leakage monitoring for the reactor vessel closure head and pressurizer bottom head penetrations where are inaccessible during the main primary system hydraulic proof test for EPR nuclear reactors. It provided reference for the acoustic...
It is a great honor to be invited here to share thoughts on the subject of “ASNT's vision on Certification of NDT Personnel with respect to current and future technologies.” My professional career mirrors this title. Most of you are experienced in multiple NDT methods, while I have only one method: infrared thermography. The name “Infrared Thermography” is a bit misleading because it refers specifically...
Conference proceedings front matter may contain various advertisements, welcome messages, committee or program information, and other miscellaneous conference information. This may in some cases also include the cover art, table of contents, copyright statements, title-page or half title-pages, blank pages, venue maps or other general information relating to the conference that was part of the original...
We present a nondestructive evaluation method, based on ultrasonic coda wave interferometry measurement with applied small successive stress change (∼10kPa to ∼140kPa) under a four-point bending test, to assess the damage level of a real-size T-beam from a deficient prestressed concrete bridge. The acousto-elasticity coefficient is 4.17× 10−3MPa−1 subject to compressional force, in associate with...
An extrinsic Fabry-Perot interferometrie (EFPI) optical fiber sensor interrogation system using reflective semiconductor optical amplifier (RSOA) is proposed. In this novel design, a resonant cavity is formed between the RSOA and EFPI sensors, each sensor can access to by tuning the modulation frequency of RSOA. Compared with common EFPI sensor interrogator, this design allows tens of sensors along...
Non-destructive detection of total volatile basic-nitrogen (TVB-N) content in fresh pork based on hyperspectral imaging (HSI) technology was evaluated. In order to build a firm hyperspectral calibration model of TVB-N content in fresh pork, discussion about the impacts of different data processing methods(sample set partitioning, characteristic wavelength selection, and so on)on the predictive results...
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