ABSTRACT The ultrasonic measurement model (UMM) has been theoretically studied over the past few decades, but there is little published work on its practical application for guiding defect detection. In this work, we present a model-based ultrasonic method to detect flaws in curved components using immersion of spherically focused transducers. The UMM of focused transducers is further investigated

ABSTRACT Defects caused by a harsh working environment and cyclic loading may seriously lead to catastrophic industrial accidents. Therefore, an efficient and accurate detection method is needed to quantitatively characterise the multiple defects of large-area metal components. In this paper, a pulsed eddy current (PEC) array is designed by considering mutual electromagnetic influence between the PEC

ABSTRACT High-strength aero-space grade maraging steels finding an increased use in industry for manufacturing of pressure vessels. Structural integrity assessment of such pressure vessels is an important and yet challenging task. Several researchers have attempted to quantify failure or structural integrity of similar pressure vessels using acoustic emission (AE) but a one stop criterion to assess

ABSTRACT The metal magnetic memory is used to detect the micro damage of structure based on the SMFL (self-magnetic flux leakage) effect, but it lacks an effective comprehensive diagnosis index suitable for the ferromagnetic material. In this paper, steel strand specimens were tensioned at different force levels, and the experimental study on the corrosion detection was carried out. Besides the monitoring

ABSTRACT This study experimentally investigates the efficacy of TE11 mode microwaves in detecting bend-region cracks. Three types of bends with different dimensions were deployed in a 3 m piping system and then tested, with an axial or circumferential slit machined at different angular positions to simulate a crack. The TE11 mode microwaves were excited using self-designed TE11 mode microwave probes

ABSTRACT This study aims a systematic experimental investigation using acoustic emission (AE) non-destructive technique for online monitoring of hydrogen assisted cracking (HAC) in modified 9Cr-1Mo steel (P91 steel) welds during Gap-Bead on Plate (G-BOP) and implant tests. Welds made without preheating, with different preheating and combined pre and post heating were tested using G-BOP test. AE results

ABSTRACT Polymer-based Glass composite cylindrical structures consisting of multi-layered configuration for special applications were tested with low magnetic field nuclear magnetic resonance (NMR) technique. Relaxation times of chemical species at the interface of adhesive bond were investigated. Studies indicated that the single-sided NMR inspection of such composite structures is a feasible non-destructive

ABSTRACT The mobility of an Unmanned Aerial Vehicle (UAV) offers significant benefits when deploying remote Non-Destructive Testing (NDT) inspections of large-scale assets. Ultrasonic inspection is primarily a contact-based NDT method, that grants the opportunity to remotely monitor the structural health of an industrial asset with enhanced internal integrity information. Presented in this paper is

ABSTRACT Since magnetic Barkhausen noise is very sensitive to the change of the stress or residual stress level in components, it is feasible to detect the stress or residual stress profile along the depth direction by the magnetic Barkhausen noise method. An engineering approach was used to validate a theoretical model describing the relationship between magnetic Barkhausen noise and stress magnitude

ABSTRACT In this paper, local damping behaviour of S0 ultrasonic Lamb mode is investigated to determine the reason of amplitude reduction of signals come from a rich resin defect in a composite plate. A four-layer woven glass fibre-epoxy (WGF/epoxy) composite plate, containing a predefined rich resin area as the damage, has been manufactured and inspected with S0 Lamb mode via through transmission

ABSTRACT For safe construction practise, it is important to monitor the hardening process of concrete during the construction stage itself. Moreover, with the increasing use of supplementary cement-based materials (SCM) in concrete construction which adversely alters (significantly delays) the setting and strength gain in concrete, it becomes highly imperative to closely monitor and examine the development

ABSTRACT This work deals with the accuracy of a non-destructive testing methodology to monitor the evolution of inter-fibre fractures in [ 90 3 / 0 2 ] s cross-ply carbon fibre-reinforced polymer laminates. Specimens are subjected to a continuous 3-point bending test. The locations of local energy releases corresponding to inter-fibre fractures are recorded during the experiment using passive infrared

ABSTRACT In this research, a thorough experimental and numerical study is conducted to investigate a novel application of the ultrasonic Lamb waves which is its capability to detect the coating disbond in a double-layer waveguide (aluminium-adhesive) and a triple-layer waveguide (aluminium-adhesive-coating). The experimental tests are set up and implemented to evaluate how the attenuation of Lamb waves

ABSTRACT A crack or any kind of damage induces a sharp discontinuity in the rotational displacement curve in a structure under load. However, if the beam is not loaded sufficiently or crack depth is very small, the discontinuity may not be possible to identify through conventional methods. This study proposes a non-destructive approach to reveal the presence of a crack in structural components based

ABSTRACT This paper aims to provide a method for detecting the circumferential crack by analysing the two reflected SH0 guided wave from the front-edge and back-edge of the circumferential crack. We established a finite element model for the propagation of SH0 guided waves in the pipe, and the waves were generated by a periodic-permanent-magnet electromagnetic acoustic transducer (PPM EMAT). The influences

ABSTRACT Knowledge of critical strains during the asphalt pavements’ life is an inherent process within pavement structural assessment. Highway agencies need this knowledge to effectively manage potential maintenance activities. Conventional practice includes mechanistic analysis of data collected in-situ. Contrariwise, developing models or algorithms for strain prediction bypasses the time-consuming

ABSTRACT This research work focuses on investigating the effect of external patch repair and its sequence on quasi-static indentation (QSI) response of glass/epoxy laminates. The parent woven glass/epoxy laminates (Type-I) was repaired by using woven (W) and chopped (C) fibres with different patch sequence such as W/W/W/W (Type II), W/C/C/W (Type III), C/W/W/C (Type IV) and C/C/C/C (Type V). The aim

ABSTRACT Detecting the debonding defects in the composite/rubber/rubber bonding structure is very difficult because of the high attenuation and aliasing of the ultrasonic wave from the structure. In order to solve this problem, a detection system was built based on the high-power ultrasonic pulse-echo method, and the time-frequency contour image of the wavelet coefficient modulus of the echo using

ABSTRACT Magnetic Barkhausen noise (MBN) method is one of the non-destructive evaluating (NDE) techniques used in industry to monitor the quality of ferromagnetic products during manufacture. In this article, case depth evaluation of the camshaft lobes by this means after induction hardening is described. A routine industrial monitoring practice is found to have limitation to evaluate the thickness

(2020). Preface special issue: industrial computed tomography – 10th conference on industrial computed tomography. Nondestructive Testing and Evaluation: Vol. 35, iCT2020 Special Issue: NTE, pp. 239-240.

In this paper, we present a fully automatic evaluation approach that can be used for fast inline CT scanning. In contrast to classical defect-recognition algorithms, this approach does not require good image quality. Instead, it allows to distinguish CT artifacts from real defects introduced in the production process. To this end, a three-step workflow was developed, in which any deviations from a

Conformal cooling channels, made by the laser powder bed fusion process, are a promising design strategy for optimising cooling and process control of manufacturing tools and injections moulds. The addition of internal features such as corrugations and ribs are becoming an interesting addition to the cooling channel designs. Internal surfaces of laser powder bed fusion components have an inherent process-induced

A side-by-side probe is typically used in eddy-current testing as it offers advantages such as good sensitivity and high signal-to-noise ratio. However, most studies regarding side-by-side probes are primarily based on circular coils. In this study, an analytical model of a rectangular side-by-side probe is developed, in which transmitter and receiver coils are rectangular and assembled side-by-side

Aiming at the difficulty of leak detection of urban hazardous chemical pipelines, this paper proposes a method for locating pipeline leaks based on the complementary ensemble local mean decomposition (CELMD) and maximum correlation kurtosis deconvolution (MCKD) secondary noise reduction. First, white noise with opposite sign was added to the original leak signal in pairs, and the noisy signal was decomposed

An important issue in analysing signals by the variational mode decomposition (VMD) algorithm is to confirm the number of modes and the balance parameter. In the applications of fault detection, most studies optimise parameters by the characteristics to extract fault information perfectly. Then, the results are used for subsequent operations such as fault analysis and classification. However, the optimal

We present visual methods for the analysis and comparison of the results of curved fibre reconstruction algorithms, i.e., of algorithms extracting characteristics of curved fibres from X-ray computed tomography scans. In this work, we extend previous methods for the analysis and comparison of results of different fibre reconstruction algorithms or parametrisations to the analysis of curved fibres.

Additive manufacturing is revolutionising the production of complex-shaped components and finding widespread application in the industries where production volumes are low and part geometries are complex. High-fidelity 3D imaging of additively manufactured metal parts, as the most effective nondestructive evaluation method, is crucial to maintaining the quality of safety-critical components during

Accurate knowledge of the acquisition geometry of a CT scanning system is key for high quality tomographic imaging. Unfortunately, in modular X-ray CT setups, geometry misalignment occurs each time the setup is changed, which calls for an efficient calibration procedure to correct for geometric inaccuracies. Although many studies have been dealing with the calibration of X-ray CT systems, these are

Robot-CT is drawing great attention for its potential to support highly flexible scan trajectories and various scan modes with a single system. However, the quality of CT reconstruction largely depends on accurate knowledge of the scan geometry, i.e. position and orientation of the source and the detector. This imposes major challenges on current serial industrial robots. In order to realistically

Robotic CT systems allow complex scanning trajectories. This work presents a workflow to automatically calculate optimised scanning trajectories for robotic CT systems. In particular, as a local quality estimation, this work introduces a quantitative measure to quantify local reconstruction quality based on the Tuy conditions. The proposed method is tested in two summation experiments using an STL

Additive manufacturing (AM) unlocks novel industrial possibilities in relation to design optimisation for lightweight structures, e.g. in aerospace applications. However, the inherent geometric complexity of topology-optimised AM components represents a major challenge for conventional non-destructive testing (NDT) methods. Due to its flexibility and high throughput, industrial X-ray micro-computed

Discontinuous prepreg platelet based carbon fibre sheet moulding compound (CF-SMC) materials offer huge potential for lightweight applications in the automotive industry. The composition of these materials and the flow behaviour during compression moulding result in a complex stochastic mesostructure, which presents a challenge in the modelling of the mechanical behaviour. The objective of the current

Based on relationships between electromagnetic properties and microstructural changes in steel, the current paper describes the development of an electromagnetic technique to determine steel hardenability, non-destructively. Performing Jominy end-quench test, magnetic hysteresis loop and eddy current methods have been applied to SAE 4140 standard steel samples to explore applicability of the non-destructive

Variations in the design requirements of prestressed concrete girders lead to variations in their geometry and section profile, thereby influencing the characteristics of the waves which form the working principles of the various NDT techniques, and thus possibly shield the presence of air void. Thus, an experimental plan was adopted to study the effect of the changes in parameters like the cover to

ABSTRACT In this study, both estimation and modification strategies of measurement uncertainty were investigated when using a guided waves (GWs) technique to quantify the corrosion level of a cylindrical rod induced by an accelerated setup, thus providing essential and reliable information for making decisions regarding necessary remedial work. First, the remnant diameters under corrosion were quantified

Damage in a pavement structure is usually initiated in the asphalt layers, making the Rayleigh wave ideally suited to the detection of shallow surface defects. However, the practical application of crack detection methods in asphalt is hampered by the dispersive behaviour of the road pavement. A new digital signal processing technique for the measurement of the amplitude and phase of the direct and

Carbon fibre reinforced plastics (CFRPs) are replacing metals in fields such as aerospace due to their high mechanical strength and low weight. They have an anisotropic behaviour, which hinders the analysis of structural impairment caused by damages like impacts. Optical lock-in thermography (OLT) can be used to assess CFRP integrity and image processing tools can be applied to measure the area affected

ABSTRACT The goal of this research is to investigate the correlation between the piezomagnetic field and the defect size in ferromagnetic steels. Specimens of 30Cr steels were machined into standard bars with circular holes of different sizes in the centre. Tensile tests were carried out to measure the piezomagnetic field on the surface of the defective specimens. The variations of the piezomagnetic

Rolling contact fatigue (RCF) cracks are the predominant reason for rail grinding maintenance and replacement on all types of railway system, as they can potentially cause rail break if not removed. To avoid excessive material removal, accurate crack sizing is required. Alternating current field measurement has been used as an electromagnetic method for RCF crack sizing, incorporating with modelling

This paper presents a new modeling approach of eddy current nondestructive evaluation systems containing magnetic materials. Originally, the proposed model is based on coupled circuits principle and the notion of equivalent current density. In order to make the model homogenous, we consider the current density as a state variable since this density is compatible with the representation of the magnetisation

Existing timber structures often present elements with different levels of decay and the choice to maintain them comes from the structural assessment, made by a civil engineer on the basis of the results coming from the on-site survey. The choice may also rely on visual inspection combined non-destructive tests. In that case, the choice to maintain an element will greatly depend on the accuracy and

A method for condition monitoring and localization of defects in mass-produced structural members using supervised learning is presented. An example for the effectiveness of the developed method comprises cantilevered carbon composite plate. In a numerical finite element model, the plate is partitioned into zones and a point mass is put on several locations within each zone. Point mass is treated as

Aiming to improve the accuracy of the contact life prediction of sprayed coatings, a series of contact fatigue tests are conducted on RM-1 tester. Five kinds of plasma sprayed Al2O3–40 wt%TiO2 composite ceramic coatings (AT40 ceramic coatings) of different quality and surface performance parameters are tested on the principle of central composite design. The passive infrared thermography is used to

Stress corrosion cracking (SCC) is a common corrosion form that involves undetected premature failures during service life of structures. Since SCC is a combination of electrochemical and mechanical phenomena, coupled acoustic emission and electrochemical noise techniques were proposed to investigate the evolution of SCC damage tomartensitic stainless steel samples. Tests were carried out using a precipitation

ABSTRACT The sensitivity of magnetic non-destructive methods to both chemical composition and microstructure has limited their potential application for determination of mechanical properties in plain carbon steels under conditions of varying carbon content and microstructure. The present paper investigates advantages of applying an artificial neural network (ANN) method to magnetic hysteresis loop

ABSTRACT Scanning contact potentiometry (SCP) is a nondestructive method used for defects detection, and for determining the location coordinates of defects in welded joints. This paper evaluates the accuracy of SCP method in detecting defects and localising them in welded steel plates. The effectiveness of the SCP method was evaluated using sample of steel 321 H plates (Chromium–Nickel–titanium stainless

ABSTRACT Being the most detrimental mode in laminated structures, delamination initially degrades local structural strength, and lastly causes global structural failure, thus necessitating delamination identification at its incipient stages. For identification purposes, a comprehensive numerical and experimental study on delamination within both the laminated isotropic acrylic-glass and orthotropic

ABSTRACT The influence of plastic deformation of low-carbon steel on birefringence of the shear waves birefringence is examined. Acoustic measurements show that the birefringence changes monotonously, while the intensity of the change decreases with increasing strain. Significant reduction of the birefringence is found to indicate that the capability to plastic deformation has been largely used. In

ABSTRACT Timber utility poles are significantly used in power and telecommunication infrastructures all over the world. The deterioration of timber with time is common due to various factors including termite attacks and climatic conditions. Failure of poles can have serious safety concerns and economic implications. Hence, the condition assessment of timber poles is important for safe and economical

ABSTRACT A finite element simulation analysis of micromagnetic signals of surface crack defects on a titanium (Ti) alloy plate was performed, and a verification experiment was designed. Simulation results showed that micromagnetic detection exhibited strong detection capability when used for crack defects with 0.15–0.6 mm widths. Good detection capability could be ensured if the detection lift-off

ABSTRACT An analytical model of eddy current field under sinusoidal excitation of a planar spiral coil is established, taking into account the gap between the turns of a spiral coil and displacement current. The developed model is firstly validated by FEM and experiments, and then was applied to investigate the influences of displacement current on eddy current signal. The results show that the increase

ABSTRACT The deformation of Carbon Fibre Reinforced Polymer (hereafter referred to as CFRP) will affect the reliability and safety of products when it is applied in the fields of aeronautics & astronautics and military, and it can provide a basis for assessing the safety performance of structures by monitoring the deformation of CFRP laminates real time. In this paper, the CFRP laminates are taken

ABSTRACT Metal artefact reduction has become a challenging issue for practical X-ray CT applications since metal artefacts severely cause contrast degradation and the misinterpretation of information about the property and structure of a scanned object. In this paper, we propose a methodology to reduce metal artefacts in a three-dimensional industrial cone beam CT system. We develop a registration

ABSTRACT This research work investigates the effect of thickness on the quasi-static indentation and tensile loading behaviour of glass/epoxy laminates. Cross-ply [0°/90°]3S laminates fabricated at different process pressures (40 kg/cm2, 50 kg/cm2 and 60 kg/cm2) were subjected to quasi-static indentation loading. Furthermore, the residual load-bearing capacity was estimated by performing tensile after

ABSTRACT Glass or carbon fibre-reinforced polymer (FRP) structures have attained a relevant role in modern production thanks to their lightweight, high resistance to corrosion and fatigue, and relative ease of manufacturing complex shapes. Nevertheless, several types of defects, such as voids, matrix fractures, delaminations and impact damages, which might significantly reduce the useful life of composite-made

ABSTRACT Quantitative evaluation of stress corrosion cracking (SCC) using eddy current testing (ECT) signals often underestimates the depth of crack due to the complex geometry and conductivity characteristics of crack. It can be approximately regarded as a multi-variable nonlinear optimisation problem considering the cross-sectional feature and conductivity distribution of crack. For the multi-variable

ABSTRACT This article presents a new approach to processing data in identifying and evaluating defects of structures with deformation measurement signals. By using sensitive characteristics observed in the old statistical parameters such as mean values, variances, and standard deviations, we propose three new parameters including kurtosis, skewness of signals, and statistical density function. In addition

ABSTRACT This article aims to improve the knowledge on ‘crack classification’ in reinforced concrete (RC) beams using acoustic emission (AE) testing and ultrasonic pulse velocity (UPV) test. The present study reports on usage of AE and UPV testing methods on fracture mode in RC structures. Gaussian mixture modelling (GMM) method was used for crack classification. Support vector machine (SVM) method was

ABSTRACT A Vibration-Based Method for assessing the integrity of welded structures is presented. The proposed technique relies on fitting theoretical predictions of a lumped mass-based model of the welding with experimental measurements obtained from modal analysis. Experiments are performed in various test platens that are soldered at one or two locations and exhibit distinct welding qualities, achieved

ABSTRACT This study is interested in how to utilise the virtual time reversal (VTR) technique to locate the continuous AE source in cylindrical shell structure. Thus, a six-AE-sensor monitoring network was designed to divide cylindrical surface into two symmetric semi-cylindrical monitoring areas whose four vertexes and two geometrical centres were defined as the measuring points. The AE source can