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

Film quality analysis is of more considerable significance due to its diversified applications in various fields of technology. The present work reports the speckle interferometric analysis of the argon pressure-induced surface roughness modifications of RF sputtered MoO3 films. The paper suggests a new method of surface quality analysis of thin films through a parameter δ, which is the difference

The spread of additive technologies from prototyping to manufacturing has made the development of new products possible, but still needs effective methods in order to allow their characterization. In particular, porosity is considered a crucial aspect of AM products. A prototype system for the deposition of continuous carbon fiber-reinforced polymers with a thermoplastic matrix has been recently developed

Flaw detection in non-destructive testing, especially for complex signals like ultrasonic data, has thus far relied heavily on the expertise and judgement of trained human inspectors. While automated systems have been used for a long time, these have mostly been limited to using simple decision automation, such as signal amplitude threshold. The recent advances in various machine learning algorithms

Construction of drilled shafts for transportation infrastructure presents quality assurance challenges related to structural anomalies, including voids and degraded concrete. Efforts to evaluate anomalies often use stress-wave non-destructive testing (NDT) techniques such as the crosshole sonic logging (CSL) method. CSL relies on the propagation of stress waves between access tubes inserted alongside

Thin-walled tubes and pipes are employed in industries to work under the conditions of high temperature, high pressure, high flow rates and radiation. Due to such stresses and harsh working conditions, tubes lead to sag during operation because of its low Wall Thickness and smaller diameters. There is a requirement to accurately measure sag and dimensions and assess the health and remaining life of

XXL-Computed Tomography (XXL-CT) is able to produce large scale volume datasets of scanned objects such as crash tested cars, sea and aircraft containers or cultural heritage objects. The acquired image data consists of volumes of up to and above \(\hbox {10,000}^{3}\) voxels which can relate up to many terabytes in file size and can contain multiple 10,000 of different entities of depicted objects

This study aims to evaluate coating adhesion durability using the laser shock-wave adhesion test (LaSAT). In particular, the interfacial strength with respect to the applied loading cycle is evaluated quantitatively. This method uses strong elastic waves induced by pulsed laser irradiation, as interfacial fracture of the coating occurs due to a strong wave. The coating delamination can be identified

Selective electron beam melting (SEBM) is an additive manufacturing process for the production of complex metallic parts. To optimize their mechanical properties, pores and fusion defects, since not completely avoidable, have to be detected and evaluated. The generated microstructure may contain not only voids, but also weak bonds, sharp interfaces and loose particles causing nonlinear elasticity.

Wire rope inspection by nondestructive testing methods, sensors and signal processing techniques are mainly reviewed in this paper. Owing to the difference of physical mechanism and testing principles, magnetic flux leakage, eddy current, acoustic emission and ultrasonic guide wave testing as well as other inspection methods for steel wire rope are summarized. Then, the commonly and frequently used

The flexible printed coil array (FPC) is employed extensively because of its flexibility in non-destructive testing (NDT). To make the inductive coil detect both external and internal defects under static conditions in magnetic flux leakage testing (MFL), this paper proposes a method based on the AC and DC composite magnetization. The AC magnetization changes the magnetic field strength in the vicinity

Stresses have great influences on the mechanical performance and corrosion resistance of pipelines. Magnetic Barkhausen noise (MBN) as an effective non-destructive testing method for evaluating stress in ferromagnetic materials has been widely studied in recent decades. Different from traditional MBN methods based on a time-varying magnetic field, this paper proposed a novel MBN method to induce Barkhausen

In this study, the physical foundations of the combined acoustic-electric method are examined for testing layered materials, as well as materials with defects in the form of solid inclusions. The numerical simulation results of the electromagnetic signals excited in a test material via pulsed acoustic impact are presented. The effect of sample layering on the electromagnetic response parameters under

The uniaxial compressive strength (UCS) is considered as a significant parameter related to rock material in design of geotechnical structures connected to the rock mass. Determining UCS values in laboratory is costly and time consuming, hence, its indirect determination through use of rock index tests is of a great interest and advantage. This study presents a prediction process of the UCS values

The knowledge of grain growth directions makes it possible to describe the material anisotropy, which helps to ensure the ultrasonic testing of welded assemblies and the assessment of their mechanical integrity. Here, we study multipass welds made of 316 L stainless steel manufactured by a Gas Tungsten Arc Welding (GTAW) process. We have developed a specific model to predict the grain growth directions

Electrical impedance tomography (EIT) uses non-invasive and non-radiative imaging to detect inhomogeneous electrical properties in tissues. The inverse problem of EIT is a highly nonlinear, ill-posed problem, which causes inaccuracy in target size calculation. We propose a novel approach to discretize the target size and use a neural network (NN) classifier to classify the unknown size in discrete

An artificial neural network (ANN) model and response surface methodology (RSM) were established to estimate the compressive strength of concrete by using the combination of three non-destructive tests (NDT); rebound number, pulse velocity tests and resistance surface. These techniques are utilized in an attempt to increase the reliability of the non-destructive tests in detecting the strength of concrete

Optical fibers (OFs) are among the most promising technologies for distributed sensing in structure health monitoring of composites. Optical backscatter reflectometer (OBR) based on Rayleigh scattering enable to use the entire length of telcom OF as sensor, giving detailed information about the stain fields in the host structure. Embedded sensors can provide many advantages over surface bonded ones

This paper presents a method for improved analysis of objects with an axial symmetry using X-ray Computed Tomography (CT). A cylindrical coordinate system about an axis fixed to the object’s center of symmetry forms the most natural base to analyze characteristics of those objects that exhibit axial symmetry, as is often the case for industrial parts. As the sampling grid in the proposed methodology

Technical advantages of additive manufacturing (AM) have drawn great attention over the past few years. This cost-effective manufacturing process proved its potential applications in a wide range of fields. Although AM techniques (known as 3D printing) are able to fabricate geometrically complex components, it is necessary to evaluate internal and external dimensions of the printed parts. In this context

Porosity is an unavoidable defect in carbon fiber reinforced polymers and has noticeable effects on mechanical properties since gas filled voids weaken the epoxy matrix. Pulsed thermography is advantageous because it is a non-contacting, non-destructive and fast photothermal testing method that allows the estimation of material parameters. Using the Virtual Wave Concept for thermography data, ultrasonic

Mid-infrared signals in the 2–5 μm wavelength range have been transmitted through samples of polymer pipes, as commonly used in the water supply industry. It is shown that simple through-transmission images can be obtained using a broad spectrum source and a suitable camera. This leads to the possibility of tomography, where images are obtained as the measurement system is rotated with respect to the

Due to its flexibility for use in various applications active thermography is of interest for non-destructive evaluation of defects in various materials. In particular, active thermography allows for identification of imperfections inside glue joints like delaminations, air pockets or inclusions of foreign particles. The contribution of this work is the development and validation of a small and portable

Nuclear material containment buildings are required to be periodically inspected to assure good quality conditions. To this end, there is increasing interest in developing efficient and economical testing techniques to monitor and inspect these structures. In this paper we study the dynamic behavior of a 1/3 mock-up containment structure and its internal pressure-dependence using testing techniques

Crack damage is commonly observed for civil structures and infrastructure in service. The recent years have witnessed an excessive utilization of deep learning models for realizing autonomous and machine-vision based crack detection. Given this trend, this paper recognizes two entwined challenges: the preparation of large-scale training data and the detection of simple crack damage amid complex scenes

This document provides a comparative evaluation of the performance of a deep learning network for different combinations of parameters and hyper-parameters. Although there are numerous studies that report on performance in deep learning networks for ordinary data sets, their performance on small data sets is much less evaluated. The objective of this work is to demonstrate that such a challenging small

Thanks to its good strength/mass ratio, a glass fibre reinforced plastic (GFRP) composite is a common material widely used in aviation, power production, automotive and other industries. In its turn, active infrared (IR) nondestructive testing (NDT) is a common inspection technique for detecting and characterizing structural defects in GFRP. Materials to be tested are typically subjected to optical

Sliding friction causes significant structural transformations in the subsurface layers of interacting materials. These changes are associated with complicated mechanochemical processes which include but not limited to plastic flow, refinement of structure, increase of dislocation density, oxidation, delamination and formation of wear debris. In this study we attempted to observe some of these processes

A damage identification scheme combining impact-synchronous modal analysis (ISMA) and artificial neural network is developed in this study. The ISMA de-noising method makes it feasible to detect and classify the damage states with high accuracy when the machine is under operation. The feed-forward backprop network was utilized in this study. The input feature vector of the network consisted of the

Parametric signal representation techniques with Chirplet models have attracted much attention in ultrasonic guided waves-based research of material property identification and structural integrity evaluation. The known Chirplet models are established using either the Gaussian windows or the linear chirp function. This is inconsistent with practical situations where the excitation is a Hanning-windowed