More than 20 years of research progress regarding the nondestructive testing method of metal magnetic memory is reviewed and summarized in detail. Consequently, this overview is selective, covering what we feel are the most important trends of experimental phenomena, mechanism explanations, quantitative theories, simulations, testing, evaluation and application. From analyzing the current state of

The article demonstrates an effective solution for ultrasonic quality monitoring of transmission and drive components of motor vehicles, joined using an innovative method called magnetically impelled arc butt welding (MIAB). The major challenge was the application of ultrasonic technology for quick and reliable testing of thin-walled components with complex geometry. To solve this problem the idea

Frequency-domain synthetic aperture focusing technique (SAFT), such as non-stationary phase shift migration (NSPSM), plays an essential role in the ultrasonic imaging of two-layered systems with non-planar interfaces. However, with NSPSM fast imaging under blind test conditions is hard to realize due to a lack of interface information in practice. To overcome this difficulty, a fast interface reconstruction

Determination of composition and thickness is crucial for the preparation of thin layers. A separate measurement is possible; however, it could be time-consuming, and each technique requires a specifically prepared sample. Therefore, a combined, fast, and reliable technique would be advantageous. Calibration of energy dispersive X-ray spectroscopy (EDS) integrated with scanning electron microscope

Imaging-based inspection techniques have practical advantages in the study and/or rehabilitation of artworks. They provide in some cases internal information on the status of the sample to be inspected. On the one hand, techniques based on active infrared thermography (IRT) are advantageous to obtaining complete images of the inspected parts, although a technical interpretation performed by a team

This study assesses the damage-detection capability of electrical resistance tomography for carbon fiber-reinforced polymer composites damaged by barely visible impact damage. Although electrical resistance tomography suffers from low spatial resolution, the method is sensitive to small conductivity changes and is therefore a suitable tool for detection of point inhomogeneity. For assessment purposes

Clustering data is an important topic in acoustic emission (AE) health monitoring. Identification of damage mechanisms in composites via AE technique requires an automatic process of classification. In this work, we propose a novel and simple supervised method to discriminate AE signals produced by fracture mechanisms in polymer composites. The novelty of this work is to propose new pertinent descriptors

The thermal conductivity of construction materials is among the main factors influencing the thermal performance of buildings. This property is, thus, extensively demanded for design purposes. The thermal conductivity is especially related to the pore system and the composition of cement-based composites, the same factors that affect their Ultrasonic Pulse Velocity (UPV). In this sense, the present

This paper is focused on the real-time characterization of weld in high speed high-end drawn metallic wires using encircling coil eddy current sensor. Emphasis was laid on the evaluation of weld-length and its span of stability with a special reference to signal pattern recognition through the improvised non-linear regression tool. A 3-D CIVA simulation electromagnetic testing module was implemented

Pulsed eddy current is an emerging technique for measuring wall thinning of steel under insulation. Ideally, it would be desirable to obtain the most localised information of pipe condition possible. The localization of information is constrained by the flow of eddy currents in the pipe. This in turn is heavily influenced by the orientation of the probe. This paper examines three different probe orientations

An easy-to-implement method based on mode-converted waves was proposed for quantitatively detecting shallow subsurface defects using the ultrasonic time-of-flight diffraction (TOFD) technique. First, an isotropic model with a shallow subsurface defect was established to analyze the ray path of the mode-converted wave in TOFD B-scan image. The mode-converted wave with the shortest travel time and highest

Unfortunately, the author had missed to include the below acknowledgement text in the original publication of the article.

Local ultrasonic resonance spectroscopy (LURS) is a new approach to ultrasound signal analysis, which was necessitated by a novel inspection method capable of the contact-free, localized, broadband generation and detection of ultrasound. By performing a LURS scan, it is possible to detect local mechanical resonances of various features and of the specimen itself. They are highly sensitive to local

Material grain size is related to metallic material properties and its elastic behaviour. Measuring and monitoring material grain size in material manufacturing and service is an important topic in measurement field. In this paper, three materials, i.e., aluminium 2014 T6, steel BS970 and copper EN1652, were chosen to represent materials with small, medium and large grain size, respectively. Various

Differential eddy current probes are commonly used to detect shallow surface cracks in conductive materials. In recent years, a growing number of research works on their numerical modelling was conducted since the development of analytical or semi-analytical models for such a sensor may be prone to intractable complications. In this paper finite element modelling (FEM) has been employed to simulate

The goal of the present study is to examine the applicability of non-destructive magnetic hysteresis loop technique and Hall effect sensor to characterize the strain induced α′-martensite in an austenitic stainless steel. For this purpose, eight different levels of tensile deformation, from 0.05 to 0.44 true stain values, were applied and corresponding induced martensite fractions were determined,

Developing a method for disassembly damage evaluation is of great significance for the key components in maintenance and remanufacturing. Disassembly of the interference fit joint between the shaft and impeller, which could inevitably bring damages to the parts’ surface, was investigated. The ferromagnetic materials FV520B (impeller) and 40CrNiMo7 (shaft) were used in the disassembly experiments. Experiments

Owing to their inherent advantages, non-metallic structures such as glass reinforced epoxy (GRE) pipes and high-density polyethylene (HDPE) pipes are rapidly replacing their steel counterparts in pipeline infrastructures. However, non-metallic pipes are vulnerable to a variety of defects which compromise their structural integrity. Hence, periodic inspection of these structures is incumbent to ensure

Bearings are one of the most widely used components in the industry that are more vulnerable than other parts of machines. In this research, a precise method was developed for diagnosis bearing detection based on vibrating signals. Vibration signals were recorded from four common faults in the bearings at three speeds of 1800, 3900, and 6600 rpm. The vibration signals were transmitted by the fast Fourier

Since small metal cylindrical shell (MCS) is a kind of very important metal object widely used in structure engineering and weapon production, especially in the manufacture of bullets, it is necessary to assure the high-precision surface of MCS. While the detection of MCS is generally done manually. In this paper, a novel automatic defect detection system for MCS is built using transfer learning of

Accurate measurement of elastic constants in resonant ultrasound spectroscopy (RUS) depends on a perfect matching in the calculated and measured mode frequencies of free vibration of the solid specimen under study. Calculation of these frequencies requires estimated values of the elastic constants of the material. The present work proposes and demonstrates a method to derive initial guess values of

Pre-insulated district heating (DH) pipes have been in use for more than 40 years. The thermal performance of these pipes decreases over time as a result of thermal and mechanical aging, which leads to higher heat energy losses. A non-destructive method based on a cooling method is under development for assessing the thermal performance of a DH network. The method utilizes the copper wire, which is

This work presents recent results of nondestructive health evaluation of the large Buddhist mural “Qifo shuofa tu” (seven Buddha sermon illustration) in the Palace Museum in Beijing, China. In this work, a square-heating thermography system and a thermal tomography method were developed for quantitative 3D evaluation of murals. In particular an image correction method was developed for removing all

Positioning and force control of an ultrasonic probe with soft contact against an object surface are important manipulation tasks for measurements in manual nondestructive contact ultrasonic testing. The use of a semispherical probe with soft contact allows a controlled increase of the contact force and energy transmission. However, successful application of contact ultrasonic testing depends on the

Acoustic scattering-based technique is one major approach for characterization purposes and non-destructive testing of structures. This paper investigates the acoustic scattering of a progressive plane wave from two-layered stainless steel/polymer cylindrical shell. The time–frequency techniques are used to study the acoustic scattering from the considered structure. The use of these techniques allows

Inspection on surface iron contaminants of stainless steel is a critical process during the manufacturing of nuclear power facilities. Highly sensitivity of image recognition on iron contamination was achieved for 316L stainless steel by adding cellulose ether and silicone polyether into phenanthroline color-change indicator. Those indicators were also compared to the RCC-M (Design and Construction

Abstract Nuclear graphite that can be used in molten salt reactors, one of the main types of fourth-generation nuclear reactors, has the properties of high purity, high density, and radiation resistance, and it also has a special pore structure that prevents infiltration of the molten salt fuel. The nuclear graphites IG-110, NBG-18, and NG-CT-50 were characterised using X-ray computed tomography (CT)

Abstract Neutron radiography (NR) is a non-destructive evaluation method for detecting the presence of hydrogenous and other neutron absorbing compounds present inside sealed metal enclosures. Most of the explosives used in pyro devices are hydrogenous or contains boron. Detection of such compounds at its location becomes very critical when it has a specified function to perform such as cable cutting

Abstract Penetrant testing (PT) is a Nondestructive testing (NDT) method used for identifying and revealing surface cracks and defects in components. Using bacteria-based suspension as a fluorescent penetrant leads a new approach to PT with the advantages of using eco-friendly chemicals, fewer steps for test process and achieving low cost. The aim of the current study is to synthesize a new fluorescein

The present study explores the capability of COMSOL Multiphysics, as a finite element modelling (FEM) tool, to model the interaction between a split-D differential surface eddy current (ECT) probe and semi-elliptical surface electrical discharge machined (EDM) notches. The effect of the small probe's lift-off and tilt on its signal is investigated through modelling and subsequently, the simulation

We present a new approach to estimate geometry parameters of glass fibers in glass fiber-reinforced polymers from simulated X-ray micro-computed tomography scans. Traditionally, these parameters are estimated using a multi-step procedure including image reconstruction, pre-processing, segmentation and analysis of features of interest. Each step in this chain introduces errors that propagate through

In this research, ultrasonic pulse echo measurements are used to quantify through thickness chemical degradation in thin mortar specimens. The degradation level is predicted using the time of travel of the acoustic wave through the thickness of the structure. The front and back wall interaction reflections are used to obtain additional information from very early stage degradation. The pulse-velocity

A feasibility study on grain noise suppression using baseline subtraction is presented in this paper. Monitoring is usually done with permanently installed transducers but this is not always possible; here instead monitoring is conducted by carrying out repeat C-scans and the feasibility of grain noise suppression by subtracting A-scans extracted from the C-scans is investigated. The success of this

An alternating current potential drop technique is presented that exploits anisotropic magnetostriction to monitor changes in applied stress in steel. The background to the technique is provided together with an ad hoc approximation that describes the sensitivity of the sensor to the underlying properties. A uniaxial loading experiment has been conducted on duplex and mild steel specimens showing that