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

ABSTRACT 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

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

ABSTRACT 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

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 based

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

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 parameters

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

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 (MHL) method

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 steel)

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 epoxy-glass

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 order to

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 operation

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 height was

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 of

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 as the research

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 technique

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 indentation

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

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 optimisation

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,

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 used for

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 by

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 be located

This paper investigates the effect of glass fibre orientation on the impact damage evolution and post-impact residual strength of glass/epoxy laminates, using mechanical and acoustic emission (AE) analysis. The glass fibre reinforced polymer (GFRP) composite laminates with stacking sequence such as 0°, 90°, [±45°] and [0°/90°] were tested. The indentation-induced damage behaviour was examined in GFRP

This work examines various approaches proposed during the last fifty years, intended for the study of the scattering fields of topology (spotting the exact location) in the magnetic flaw detectors of steel wire ropes caused by damage in various types of wire ropes. In this study, the known steel wire rope models and their damages are compared. The preservation of low degree of reliability in the modelling

The manufacturing of Fibre Metal Laminates, consisting of alternating layers of pre-preg fibre and metal is complex, and defects can be introduced during manufacturing. The automation of the manufacturing steps is vital for future Glare production, and specific defects have to be considered. Among them, gaps between pre-preg plies represent a potential risk for the mechanical performances of the laminate

This study proposes a probability of detection (POD) model for the probabilistic analysis of the detectability of electromagnetic acoustic resonance (EMAR) method for the detection and evaluation of pipe wall thinning. Forty-one carbon steel plate samples with an artificially corroded groove were prepared to simulate pipe wall thinning caused by flow-assisted corrosion. Experiments were performed to

This study mainly investigates the effects of binder content, water to binder (w/b) ratio, activator dosage, and sodium silicate to sodium hydroxide (SS/SH) ratio on uniaxial compressive strength (UCS) and ultrasonic pulse velocity (UPV) of cemented paste backfill (CPB) containing AAS (AAS-CPB). Experimental results show that both UPV and UCS of AAS-CPB increases linearly with increasing binder content

Ultrasonic transducer (UT) systems are used for non-destructive testing and evaluation across a wide range of industries. In the nuclear industry, radiation damage of the UTs can lead to performance degradation or even complete failure. We have investigated the radiation resilience of a new piezo-polymer (PVDF) UT design. The irradiations were performed in a Cobalt-60 gamma facility with total ionising

The crankshaft is the core component of a piston engine. Once a bending deformation fault occurs in the crankshaft, it can cause serious damage to the safe operation of the entire engine. However, diagnostic methods for detecting this fault are rare. In this paper, the influence of a bending micro-deformation of the crankshaft (BMDC) on the gear transmission system (GTS) was studied through theoretical

This study presents an assessment of the failure behaviour and damage mechanisms of thick carbon/aramid hybrid woven composites with different fibre orientations in three-point bending test. The specimens are divided into 0° (principal material directions of aramid fibre), 90° (principal material directions of carbon fibre) and 45°, respectively. Acoustic emission (AE), infrared thermography (IRT)

This paper demonstrates the relationship between acoustic emission (AE) method parameters and loaded pneumatic cylinders. The cylinders in our experiment were loaded gradually by different weights in a vertical direction. The effect of the defect occurs when the cylinder is loaded at the retreat and progress strokes. This defect affects the relationship between the applied load and the recorded signal

In this paper, a combination of non-destructive magnetic technique and artificial neural networks is introduced, firstly, to ensure that the heat treatment process applied to a given API X65 steel sample results in desired microstructure and mechanical properties and secondly, to determine thickness variation which may occurs as a result of corrosion effect. To evaluate the effects of microstructure/mechanical

Finite element models with explicitly modelled mesoscale heterogeneity in material are introduced to numerically investigate the correlation between the ultrasonic higher harmonics and plastic deformation. The model predicts the changes of the second- and third-harmonics due to the plastic deformation in materials without the microstructural information and state variables at each loading step. The

Nondestructive testing for internal defects is necessary owing to the extensive application of metal balls in different industrial fields. The flat-bottom holes (FBHs) are used as the reference standards for the detection of internal defects. An ultrasonic measurement model with spherical-focused transducer based on multi-Gaussian beam is proposed to describe the detection of FBHs inside the metal

Determination of the axial load acting on steel reinforcement tie-rods is of crucial importance for ensuring the effectiveness and safety of structures, especially in the case of ancient masonry buildings. Many non-destructive dynamic techniques have been proposed and successfully tested over recent decades; however, ancient tie-rods can be affected not only by excessive loads but also by cracks, flaws