This article presents an innovative technique for detecting flaws in conductive materials by using an ideal filamentary coil. To characterize such a coil accurately and explicitly, it is sufficient to be in possession of merely two parameters: the radius of the circle within which all the turns are located and the distance of the coil from the tested surface. The mathematical model derived using the

Quality assurance and condition assessment of concrete structures is an important topic world-wide due to the aging infrastructure and increasing traffic demands. Common topics include, but are not limited to, localisation of rebar or tendon ducts, geometrical irregularities, cracks, voids, honeycombing or other flaws. Non-destructive techniques such as ultrasound or radar have found regular, successful

The effects of temperature fluctuations in the impedance measurements’ spectral estimates confuse the procedures to distinguish actual states’ classification, demanding compensation. The present paper demonstrates a new method to achieve temperature compensation based on a Transfer Component Analysis (TCA), a subtype of transfer learning, of the features from a source domain (in a well-known labeled

The demand of non-destructive methods to detect cracks caused by fatigue or brittle behavior in large steel structures has increased in the last years. Thermography based on electromagnetic induction is a promising method to detect cracks in weld seams and notches. This paper presents a portable experimental setup, which allows to perform in situ crack detection tests on large steel structures. The

Fatigue damage and micro-cracks growth have been proved to be closely related to the nonlinear effect of ultrasonic Lamb waves propagation in materials. In this paper, the relationship among fatigue life, length and width of micro-cracks, and the acoustic nonlinearity parameter was established. The variation of the acoustic nonlinearity parameter caused by fatigue damage was analyzed based on micro-cracks

Across so many industries, non-destructive evaluation has proven its worth time and again through quality and safety assurance of valuable assets. Yet, over time, it became underappreciated in business decisions. In most cases, the data gathered by NDT is used for quality assurance assessments resulting in binary decisions. And we seem to miss out on value of the information content of NDE which goes

The nonlinear shear of resin in fiber reinforced plastic composites is a plastic feature that cannot be ignored. Some materials scientists were often stuck on how to in situ characterize accurately shear nonlinear property of the modified resin in the composite. In this paper we try to solve this problem. Firstly, we adopted DIC method to measure the full-field shear strain; secondly we adopted a Ramberg–Osgood

Carbon steel is an important component in reinforced concrete structures. These composite materials are susceptible to various degradation processes, especially the corrosion of steel bars. Since they play an important role in the stability of reinforced concrete structures, these structures require periodic inspections to verify their physical conditions. Therefore, a nondestructive testing technique

The present work estimated the accuracy of non-destructive tests in quantifying the delaminated area in CFRP samples submitted to a 4-point end notched flexure test, to evaluate the relevance of measuring the delamination area to calculate fracture toughness in mode II, instead of of the traditional method which evaluates the delamination length visually through the sample lateral faces. In this way

Large storage tanks are heavily used to hold liquid in the oil and gas industry. The thickness mapping of the storage tank floor is carried out from inside the tank periodically during out-of-service inspection using a variety of non-destructive testing methods. Screening the storage tank bottom from the external annular ring to identify whether the tank requires further inspection or repair would

Laminated composites are complex multifunctional materials and often endure barely visible damage which is characterised by matrix cracks and fiber damage leading to delamination. These composites are often used in safety-critical industries such as aeronautical and automotive industries which makes it crucial to have techniques to assess damage before and during use. This paper presents full-field

Trees are vital resources to human ecology. Many trees, wooden logs and timbers lose their quality when they degrade due to fungal decay and insect attacks. In this work, stress wave method and radiography technique are the Nondestructive Evaluation (NDE) tools employed to check the presence of the defects in an Artocarpus heterophyllus wooden log. The influence of these defects, especially, the fungal

Bolt preload is a critical parameter in bolted connections with a strong influence on their general structural behavior. Traditional bolt preload estimation methods are sensitive to the surface conditions of the fastening elements while more accurate measuring methods might require significant modifications of the connection, such as embedded sensors. In this study, a novel contactless bolt preload

Under the effect of applied fatigue loads, high stress concentration appears at the coating/substrate interface where cracks tend to initiate. In order to monitor the interfacial crack initiation, a two-dimensional cohesive zone model is introduced to actuate the magnetomechanical model to describe the interfacial damage evolution process by measuring the residual magnetic field. The variation of residual

Several studies demonstrate the effectiveness of pulsed thermography for detection and visualization of sub-superficial flaws in composites. Continuous improvement of thermal data manipulation makes active thermography an attractive and powerful inspection method for industrial process control and maintenance aims. Therefore, temperature image-processing is the major ongoing challenge in the thermographic

The potential to provide improved performance for advanced composites through the addition of multi-walled carbon nanotubes (MWCNTs) to carbon fiber composites is of interest in several applications. To investigate performance four types of composite specimens with different off-axis angles were subjected to progressive tensile loading. The results show that MWCNTs can improve the bearing capacity

A grout layer between precast concrete components in an assembly structure is required to bear high axial loads and withstand significant shear forces during earthquakes. Since the grout layer usually exists in a narrow space, examining the quality of the layer, particularly detecting debonding at the interface, is a difficult task. However, a debonding defect at the interface is likely to significantly

Radiography testing (RT) is a well-established non-destructive method for the detection and measurement of defects in the welded objects. Unfortunately, however, the image quality of radiographs is often low mainly due to the unavoidable detection of scattered X-rays. This superimposed noise on the images could result in low detectability and inaccurate dimensional measurement of such defects. Application

When ultrasonic time-of-flight diffraction (TOFD) B-scan is implemented along the circumferential direction of pipeline, the ray path of direct longitudinal wave (DLW) is not parallel to the curved pipeline surface, inducing the layered dead zone. In this paper, the spectrum analysis method based on Fourier transform is employed to establish the relationship between flaw depth and harmonic frequency

Like with the previous revolutions the goal of the fourth revolution is to make manufacturing, design, logistics, maintenance, and other related fields faster, more efficient, and more customer centric. This holds for classical industries, for civil engineering, and for NDE and goes along with new business opportunities and models. Core components to enable those fourth revolutions are semantic interoperability

Two phase flows are of particular importance in various research fields. In the current article, a novel system consists of an X-ray tube and one sodium iodide crystal detector with ability of determining type of flow regime as well as void fraction percentage of a two phase flow, is proposed. MCNP-X code was used for physical modelling of the proposed system and its performance. Radial basis function

It is a known fact that infrared radiation is produced by all objects with a temperature above absolute zero. In fruits, IR light sensor senses the invisible areas and exposes obscure objects in the image. In normal RGB images, it is very difficult to predict the internal defect of the fruit accurately without chopping it into pieces. In this paper, a thermal IR imaging-based fruit defect detection

It is common on space vehicles to have thermal insulation adhesively bonded to a metal structure. A typical defect in such structures is an interlayer disbond, which may occur either between the insulation and the metal substructure or between the layers of multilayer thermal insulation. One-sided thermal nondestructive testing (TNDT) using surface optical heating, such as Xenon flash or quartz tube

The gearbox is one of the key components of the high-speed train system. In order to predict the fatigue damage behavior of high-speed train gearbox shell material, we propose a new method. Because the fatigue process is long and there is no whole life fatigue damage data of the shell, the performance degradation method and acceleration test with acoustic emission instrument have been used. A new Adaboost

GFRP pipes are increasingly used all around the globe mainly because of its high corrosive resistance and light weight properties. GFRP are employed in the industries involving chemical processes, such as, water treatment, desalination and in petrochemical industries for handling oil & gas at offshore platforms. The studies on the reliability of the GFRP pipes and its defect occurring probabilities

Establishing probability of detection (POD) or reliability of various nondestructive testing (NDT) techniques is essential for implementing damage tolerant (DT) methodology for aero-engines. This POD is usually established with the help of a large number of service expired aero-engine components containing several fatigue cracks. In the absence of such components, artificial defects such as electrical

Eddy current testing for thickness measurement has great advantages, such as non-contact, low cost, and high efficiency. It is reported that there is a linear relationship between the tangent of the phase angle of impedance change and the thickness, termed as the approximate linear method (ALM). However, the accuracy of ALM is not very good, especially when the thickness of a specimen is very thin

The paper analyses the possibility of post weld heat treatment (PWHT) quality assessment with the help of magnetoacoustic emission (MAE) signal measurements. Two welded superheater tubes, made of high chromium VM12 steel, were analysed—as welded and heat treated one. The analysed sample in the as welded state exhibited significantly higher hardness, accompanied by a big difference in the MAE signal

When chirp pulse compression technology (PCT) is applied in Electromagnetic Acoustic Transducers (EMATs), the frequency response characteristic of the EMAT testing system may be inconsistent with the chirp signal bandwidth. Furthermore, it causes a loss in the frequency spectrum and distortion of the ultrasonic echo waveform, leading to a decrease in the signal-to-noise ratio (SNR) and range resolution

Fibreglass components employed in the marine environment are susceptible to moisture ingress, resulting in a degradation of mechanical properties. The nondestructive testing and evaluation of such materials using acoustic methods is possible under certain conditions, but the detection of internal voids and delaminations is masked by the presence of water in such internal flaws. Herein, we present an

Detection of corrosion at rivet sites in a multilayer structure of an aircraft is an essential task to ensure the flight safety of an aircraft. It is challenging to detect the corrosion due to the influence on the signal of the rivet and the multiple fastened layers in the structure. In this letter, an electromagnetic testing method is used in conjunction with principal component analysis (PCA) to

Oil downhole metal pipe wall thickness measurement is of great importance for pipe evaluation and maintenance. Regular pipe inspection can be used to prevent pipe failure, which could otherwise lead to major failure and financial loss. In this paper, a low-frequency remote field eddy current (RFEC) based internal testing approach is presented, and the analytical solutions of the RFEC electromagnetic

The assimilation of simulated and measured data is essential for advancing technology in NDE 4.0. In this study, a particle filter (PF) was applied to identify the geometry of flaws for ultrasonic nondestructive testing. A PF based on a probabilistic approach that allows errors in measurement and simulation models may be of great assistance for the data assimilation. In the PF, state variables are

A numerical approach for analyzing the guided wave propagation behavior in a functionally graded material (FGM) hollow cylinder is presented. Based on the three-dimensional linear elasticity theory, the state matrix form of displacement and stress component is introduced into the differential governing equation. Combining with boundary conditions, the dispersion characteristic equations can be constructed

In this paper, we propose a novel detection technology to telemeter microcracks in concrete structures using an infrared thermal imager carried by an unmanned aerial vehicle and explore the thermal excitation method applicable to it. Moreover, this paper presents a selective thermal stimulation scheme design for microcracks in concrete, in which NaAlO2 and NaHCO3 solutions, whose temperatures are higher

This paper reports the results of acoustic parameter measurements in a deformed material with simultaneous recording of autowave patterns of localized plastic deformation for steels of various compositions. It discusses the possibility of using an autowave model for the derivation of structural strength criteria of materials. It was shown that the time and place of future fracture in steel specimens

This paper describes a novel method for thickness measurement in conducting material by combining the measurement of the decaying induced eddy current and its associated apparent conductivity calculation. In conventional frequency domain NDE (Non-destructive Evaluation), the skin depth is the limiting factor due to the single frequency excitation. In contrast, with a pulsed excitation, the induced

The article “Contextual Application of Pulse-Compression and Multi-frequency Distance-Gain Size Analysis”.

In this paper, Artificial Intelligence (AI) algorithms are employed for first, automating the process of creating a large synthetic Total Focusing Method (TFM) imaging dataset using a small set of Finite Element (FE) simulation datasets, and second for the automated defect-recognition (ADR) in butt-welds. In this paper, six types of imaging datasets are created with three approaches. In the first approach

The wind energy sources promote the generation of electricity, being environmentally safe, clean and its use has been growing in Brazil, especially in the northeastern states with the implementation of new wind farms. Wind turbines, however, are subject to weather, risk of animal shocks, materials carried by the wind, and the vibrations of the system itself. The blade is the most important component

The threaded sleeve connection (TSC) is widely used in the connection of reinforcing bars and the looseness is difficult to observe directly. The guided wave (GW) can be used to detect TSC’s looseness due to its ability to propagate to invisible regions, which is difficult to identify with traditional signal processing methods if the looseness is slight. In this study, we employ the convolutional neural

Previous research (Li et al., Understanding the disharmony between dropout and batch normalization by variance shift. CoRR abs/1801.05134 (2018). http://arxiv.org/abs/1801.05134arXiv:1801.05134) has shown the plausibility of using a modern deep convolutional neural network to detect flaws from phased-array ultrasonic data. This brings the repeatability and effectiveness of automated systems to complex

X-ray computed tomography (CT) is a powerful technique for non-destructive volumetric inspection of objects and is widely used for studying internal structures of a large variety of sample types. The raw data obtained through an X-ray CT practice is a gray-scale 3D array of voxels. This data must undergo a geometric feature extraction process before it can be used for interpretation purposes. Such

Acoustic emission (AE) is employed in this study to monitor piping failure process in the dike subjected to varied head action. Piping is the main reason for the seepage failure of dikes and dams, and the AE characterization of piping process is investigated. The laboratory experiments and data analyses were carried out using specially designed physical model and data acquisition systems. The monitored

In a human body, the femur is one of the strongest and longest bones and commonly fractured bone shown in the last decades, especially in elderly humans. Common femur fractures are caused due to violent trauma and severe accidents. The complex structure and response of the bone under dynamic loading conditions will provide extensive information about the mechanical properties of the bone. In this work

The conservation of the works of art represent a topic of global interest. The development of effective tools based on advanced technology for analysing and monitoring their health-state is essential to assuring their preservation. In fact, detecting and preventing the formation of defective areas or assessing for an accurate pre-restoration analysis are the main objectives of non-destructive inspection

High precision ultrasonic time-of-flight measurement is a well known part of non-destructive evaluation used in many scientific and industrial applications, for example stress evaluation or defect detection. Although ultrasonic time-of-flight measurements are widely used there are some limitations where high noise and distorted ultrasonic signals are conflicting with the demand for high precision measurements

For medium- and high-carbon stainless steels, welding can induce sensitization in the heat affected zone (HAZ) adjacent to the weld, where chromium carbide \((\hbox {Cr}_{23}\hbox {C}_{6})\) precipitates out of the bulk metal and accumulates at the grain boundaries. This chromium depletion and precipitate accumulation at grain boundaries makes the alloy susceptible to intergranular corrosion, environmentally

For defense applications, rapid X-ray inspection of propellant samples is essential for the identification and assessment of defects. Automation of this process using artificial intelligence is possible by properly training a neural network model. Convolution Neural Networks (CNNs) have recently demonstrated excellent success in both the tasks of image recognition and localisation using an adequate

The challenges presented by the global pandemic and slump in oil prices have imposed costly avoidance measures and delayed project timeliness, but it also has created the opportunity for innovation conditions in industrial non-destructive testing. The evolutional path leveraged by Industry 4.0, present sustainable offerings of robotic platforms, digital solutions and connected devices commonly known

Structural health monitoring using nonlinear guided waves have found to be of great importance. The detection of micro/fatigue cracks in the early stage is essential to avoid catastrophic failures. This paper presents a defect localization technique using nonlinear interaction primary Lamb wave modes. The nonlinearity employed here is due to clapping behaviour of crack surfaces. Two counter-propagating

The vibration-based damage identification techniques use changes in modal properties of structures to detect damages. However, the results of these methods are not reliable under noise. Therefore, it is essential to clarify which method performs vigorous under noisy conditions. In this study, three damage detection methods, called modal strain energy-based damage index, modal flexibility, and modal

Reinforced concrete bridges are iconic parts of modern infrastructure. They are designed for a minimum service life of 100 years. However, environmental factors and/or inappropriate use might cause overload and accelerate the deterioration of bridges. In extreme cases, bridges could collapse when necessary maintenance lacks. Thus, the permanent monitoring for structure health assessment has been proposed

The acoustic emission (AE) technique was employed to monitor crack formation in the water-saturated ceramic material subjected to freeze–thaw cycles. The samples with water accessible porosity ranging from 6 to 50 vol% were prepared from the illite-rich clay by the sacrificing template method. The experimental samples were fired to 1100 °C in the static air atmosphere. Afterward, they were saturated

This work focuses on the relation between the sphericity and compactness parameters obtained from the exhaustive analysis on the graphite nodules of a spheroidal graphite cast iron sample, in order to propose a methodology with allow establishing different quality categories of nodules. The experimental methodology involves X-ray micro-computed tomography on an ad hoc test sample to generate high-resolution

The hammering method used by inspectors is generally applied to inspection of looseness of bolted parts. This method entails active sensing through the input of an excitation signal produced by the inspectors, and has the advantage of practical experience acquired over many years. The sound (vibration) and sensation produced upon excitation by a hammer can be used as indices, but also leads to the

The semi-solid sintering of a novel Ti6Al4V/CoCrMo biomedical composite was investigated for the first time by semi-in situ X-ray computed microtomography. Composite was fabricated by dry mixing 15 vol% CoCrMo reinforcing particles with Ti6Al4V particles as matrix. The mixture was poured into a 1 mm diameter quartz capillary. 3D images of the same sample were acquired before and after sintering at

Cyber technologies are offering new horizons for quality control in manufacturing and safety assurance in-service of physical assets. The line between non-destructive evaluation (NDE) and Industry 4.0 is getting blurred since both are sensory data-driven domains. This multidisciplinary approach has led to the emergence of a new capability: NDE 4.0. The NDT community is coming together once again to

Convolutional neural networks were used for multiclass segmentation in thermal infrared face analysis. The principle is based on existing image-to-image translation approaches, where each pixel in an image is assigned to a class label. We show that established networks architectures can be trained for the task of multiclass face analysis in thermal infrared. Created class annotations consisted of pixel-accurate

Spectral CT can separate basis materials, and thus it can provide information on material characterization and quantification. Such information can benefit various clinical applications. However, the presence of non-ideal effects in X-ray imaging systems limits the accuracy of basis images. To achieve high accuracy of material decomposition and high quality of basis images, a novel direct iterative