Phased array ultrasonic S-scan testing of near-detection-surface defects based on a background subtraction algorithm

This paper proposes a new testing method, phased array ultrasonic testing, for the internal defects of gear teeth, which can be used to inspect the teeth of final products, breaking the limitations of incomplete volume coverage of conventional ultrasonic testing. This paper mainly discusses the inspection process of phased array ultrasonic testing, and verifies the feasibility of phased array ultrasonic testing for gear teeth defects of finished products by using physical and chemical inspection technology. The practical application results show that the phased array ultrasonic testing technology uses sector scanning mode to scan the area comprehensively between the pitch circle and the base circle, and the inspection image displayed by the equipment is intuitive, which can clearly identify defects. The number of defects inspected by phased array ultrasonic testing is consistent with the results of the physical and chemical inspection technology. The above summary shows that phased array ultrasonic testing is feasible, and the test results are reliable.

All three regions of Framatome ANP (Intercontrole in France, intelligeNDT in Germany, and Framatome ANP Inc. in the US) perform pressurized water reactor (PWR) vessel examinations however; each region has historically used different technologies to perform this work. A study was performed in 2001 to assess the feasibility of a common reactor vessel examination tool to service world markets. Although the study concluded there would be some necessary differences regarding regional code considerations, a common set of building blocks could be developed as a foundation for a next-generation tool. A plan was formulated to jointly produce a Trans-World reactor vessel examination System (TWS) to support all three markets. Generally the building blocks included a new robot, a phased array ultrasonic test (PAUT) system, and an advanced analysis system. The advanced robot design was substantially completed in 2002 and was developed to support conventional ultrasonic test (UT) methods with the flexibility to change over to PAUT technology after PAUT qualifications are complete. The robot is designed for higher accuracy and faster scan speeds than previous delivery mechanisms and to facilitate in-containment logistics resulting in shorter vessel occupation times (VOT). This paper discusses the collaborative TWS development project.

Ultrasonic testing of thick and thin Inconel 625 alloys manufactured by laser powder bed fusion

For inspection of thick-walled (50mm) copper canisters for final disposal of spent nuclear fuel in Sweden, ultrasonic inspection using phased array technique (PAUT) is applied. Because thick-walled copper is not commonly used as a structural material, previous experience on Phased Array Ultrasonic Testing for this type of application is limited. The paper presents the progress in understanding the amplitudes and attenuation changes acting on the Phased Array Ultrasonic Testing inspection of copper canisters. Previous studies showed the existence of a low pass filtering effect and a heterogeneous grain size distribution along the depth, thus affecting both the detectability of defects and their “Probability of Detection” determination. Consequently, the difference between the first and second back wall echoes were not sufficient to determine the local attenuation (within the inspection range), which affects the signal response for each individual defect. Experimental evaluation of structural attenuation was carried out onto step-wedge samples cut from full-size, extruded and pierced & drawn, copper canisters. Effective attenuation values has been implemented in numerical simulations to achieve a Multi Parameter Probability of Detection and to formulate a Model Assisted Probability of Detection through a Monte-Carlo extraction model.

Internal damage evaluation of composite structures using phased array ultrasonic technique: Impact damage assessment in CFRP and 3D printed reinforced composites

The orthotropic steel deck is a welded structure consisting of a flat and thin steel plate stiffened by a series of longitudinal ribs with support by orthogonal crossbeams. Since its development in 1950’s, the orthotropic steel deck system has been utilised all over the world. Over the last few decades, many reports have been published concerning fatigue cracking in orthotropic steel decks resulting from the complicated welded details and minimised plate thickness to reduce weight. In Japan, more than 2,300 orthotropic steel deck bridges have been constructed so far and fatigue cracking in orthotropic steel decks has been observed mainly in heavily trafficked urban expressways. In 1980’s and 1990’s, fatigue cracking at the rib-to-crossbeam connection and the welded rib splice was a major issue, while during the last 15 years, fatigue cracking at the rib-to-deck welded joint has been increasingly observed where trapezoidal ribs are used. The objective of this paper is to present a novel inspection method using phased array ultrasonic testing for rib-to-deck welded joints of orthotropic steel decks. Phased array ultrasonic testing has been used for medical diagnosis for more than forty years. Meanwhile, application of the phased array ultrasonic testing to industries wasn’t so popular until 1990’s, and then the rapid technology development encouraged the use of phased array ultrasonic testing in the industrial field. A phased array ultrasonic probe consists of multiple transducer elements each of which can act as a single ultrasonic transducer. The transducer elements are arranged in various patterns where individual and independent driving of an element must be attainable without inducing vibration in nearby elements and the performance of each element must be as close as possible for the formation of a homogeneous beam. Due to the ability to control the acoustic characteristic of ultrasonic beams, phased array ultrasonic systems can achieve the electronic scanning techniques that are not made possible by using conventional ultrasonic systems. Three main advantages of phased array ultrasonic testing over conventional ultrasonic testing are increased inspection sensitivity, increased inspection coverage and decreased inspection time. Fatigue cracks initiated at the rib-to-deck weld root can grow into either the deck plate or the weld bead. Therefore, in order to detect fatigue cracks at the rib-to-welded joint as internal part-through cracks at the early stage of development, both the deck plate and the weld bead are necessary to be examined. In view of this, an electrically driven scanner holding twin phased array ultrasonic probes is developed, allowing us to perform simultaneous examination of the deck plate and the weld bead (Fig. 1). The developed scanner is applied to the orthotropic steel deck of the Meiko-Chuo Bridge, a three-span steel cable-stayed bridge and the ability to detect internal part-through cracks in the weld bead is verified. Figure 1 Electrically driven scanner holding twin phased array ultrasonic probes (a) general view drawing and (b) schematic of twin probes fixed to the deck plate and the rib wall. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig29_1.tif/>

ABSTRACTNondestructive evaluation (NDE) techniques of phased array ultrasonic testing (PAUT) and digital X-ray radiography were employed on friction stir (FS)-welded Aluminum Alloy (AA)-2219-T87 specimens. PAUT intricacies required for scanning of FS-welded specimens with a 10-MHz 32-element transducer are discussed. The time corrected gain (TCG) calibration is required for scanning with an increase in index offset to compensate for decrease in A-Scan signal peak amplitude. Calibration techniques to find small defects with appropriate size tolerances are also established. The NDE technique of digital X-ray radiography is compared to PAUT, where it was found that a calibrated PAUT system is able to discover defects less than 0.2 mm where X-ray radiography could not. Incomplete penetration (IP), wormhole (WH), surface cavity (SC), and internal void (IV) defects are analyzed. Furthermore, an online PAUT system for FSW has been developed and successfully tested. The work provided herein will provide a gateway for an ultimate goal of an automated PAUT online sensing system.

In the recent past, Non-Destructive Testing (NDT) has become the most popular technique due to its efficiency and accuracy without destroying the object and maintaining its original structure and gathering while examining external and internal welding defects. Generally, the NDT environment is harmful which is distinguished by huge volatile fields of electromagnetic, elevated radiation emission instability, and elevated heat. Therefore, a suitable NDT approach could be recognized and practiced. In this paper, a novel algorithm is proposed based on a Phased array ultrasonic test (PAUT) for NDT to attain the proper test attributes. In the proposed methodology, the carbon steel welding section is synthetically produced with various defects and tested using the PAUT method. The signals which are acquired from the PAUT device are having noise. The Adaptive Least Mean Square (ALMS) filter is proposed to filter PAUT signal to eliminate random noise and Gaussian noise. The ALMS filter is the combination of low pass filter (LPF), high pass filter (HPF), and bandpass filter (BPF). The time-domain PAUT signal is converted into a frequency-domain signal to extract more features by applying the Empirical Wavelet Transform (EWT) algorithm. In the frequency domain signal, first order and second order features extraction techniques are applied to extract various features for further classification. The Deep Learning methodology is proposed for the classification of PAUT signals. Based on the PAUT signal features, the Deep Convolution Neural Network (DCNN) is applied for further classification. The DCNN will classify the welding signal as to whether it is defective or non-defective. The Confusion Matrix (CM) is used for the estimation of measurement of performance of classification as calculating accuracy, sensitivity, and specificity. The experiments prove that the proposed methodology for PAUT testing for welding defect classification is obtained more accurately and efficiently across existing methodologies by providing numerical and graphical results.

Irregular structure welds are used in numerous military industries. This paper is interested in how to utilize phased array ultrasonic testing (PAUT) to identify and locate irregular structure weld defects. In this paper, CIVA simulation results were compared with inspection results of known defects and were found to be in very good agreement. This shows the feasibility of CIVA simulations. The coupling, among process parameters, affects the amplitude drop value from the peak to the trough of defects signal response, which represents the lateral resolution of internal weld defects and affect the imaging quality directly. Thus, the proper setting of detection parameters is critical to improve the testing efficiency and the imaging quality. This paper uses the response surface methodology (RSM) to design the test and conduct a factorial test to analyze the effect of each parameter. Modelling of the parameters and the response is conducted through center composite design (CCD) to analyze the coupling among multiple parameters and the reliability of the model. In the process of PAUT, the response surface plot, contour plot and the initial design domain of process parameters were combined for weld defects to determine the optimal parameters rapidly and correctly. Besides, CIVA simulation could further verify optimized detection parameters and position in industry site. Finally, irregular structure weld defects were identified accurately with PAUT imaging.

This study investigates microcracks and lack of sidewall fusion in API 5 L X70M grade submerged-arc welded (SAW) pipes using nondestructive testing (NDT) methods. Through metallographic analysis and advanced NDT techniques, including ultrasonic testing (UT), radiographic testing (RT), and phased array ultrasonic testing (PAUT), the origins and impacts of these defects on pipeline integrity are examined. The results reveal that slag entrapment and improper fusion, stemming from welding process inconsistencies, are primary causes. The findings provide actionable insights into prevention strategies, such as optimized welding parameters and enhanced quality assurance measures, for ensuring the reliability of high-strength pipeline steels.

Phased array ultrasonic testing, an effective ultrasonic testing (UT) technology, has been widely used in steel inspection because of its high accuracy, sensitivity, and efficiency. However, as its application in as-cast magnesium alloys has just begun, more research is needed. Considering the important role of the gain compensation in quantifying defects in magnesium alloys by ultrasonic phased array technology, the effects of microstructure, the position, size, and overlap of defects, and boundary distance (distance from the defect position to the side surface of the test casting) on gain compensation of as-cast AZ80 and AZ31 magnesium alloys were studied. Results show the gain compensation increases with the increase of grain size. There is a strict linear positive correlation between gain compensation and defect depth, but such relationship no longer exists due to the defects overlap, orientation and boundary distance. In addition, there is a strict linear negative correlation between the gain compensation and defect size.

The article presents results of tests performed to determine the noise level in ultrasonic Phased Array testing. The tests, involving non-alloy steel S355 and austenitic steel X5CrNi18-10, were carried out applying a frequently used test configuration and 16-element 5 MHz array probes having an aperture of 10 mm ×10 mm. The obtainment of a differentiated structure, i.e. characterised by various grain sizes, required the performance of special heat treatment processes. Metallographic tests, concerning both steel grades, were performed to quantify the grain size. Specimens containing artificially made SDH Ø3 cylindrical reflectors and spherical reflectors having various diameters were made of the material prepared in the above-presented manner. The tests also involved amplitude measurements and the identification of the noise level of the reflectors. The test results enabled the quantitative determination of the signal-noise ratio, affecting the detection of low-amplitude indications.

Turbine blades are core components in turbine. It is of great significance to diagnose the blade failures at early stage and regularly inspect them at run time. Based on the analysis of blade failures, a comprehensive application summarize of different non-destructive testing techniques in blade inspection was made in this paper. The non-destructive testing techniques include visual testing, liquid penetrant testing, magnetic particle testing, radiological testing, conventional ultrasonic testing, ultrasonic phased array testing, eddy current testing and metal magnetic memory testing. The applicability and limitation of different methods were demonstrated through comparison and analysis.

Describes the application of electronic technology in nondestructive testing of aerospace materials, including the application of radiographic testing, eddy current testing, ultrasonic phased array testing, laser ultrasonic testing, and other testing, and analyzes the advantages of its use in improving the accuracy, speed, and reliability of testing.

Large-field detection of Metal/CFRP hybrid composites based on air-coupled laser ultrasound