Imaging defects in austenitic welds presents a significant challenge for the ultrasonic non-destructive testing community. Due to heating process during their manufacture, dendritic structure develops, exhibiting large grains with locally anisotropic properties which cause waves scatter and refract. When basic imaging algorithms, typically make constant wave speed assumptions, are applied datasets arising from inspection of these welds, resulting defect reconstructions often distorted...

Ultrasonic phased array systems have become increasingly popular in the last 10 years as tools for flaw detection and characterization within nondestructive testing industry. The existence location of flaws can often be deduced via images generated from data captured by these arrays. A factor common to imaging techniques is subjective thresholding required estimate size flaw. This paper puts forward an objective approach which employs a mathematical model. By exploiting relationship between...

Traditional imaging algorithms within the ultrasonic non-destructive testing community typically assume that material being inspected is primarily homogeneous, with heterogeneities only at sub-wavelength scales. When medium of a more generally heterogeneous nature, this assumption can contribute to poor detection, sizing and characterisation defects. Prior knowledge varying wave speeds component would allow accurate defects, leading better decisions about how treat damaged component. This...

The non-destructive testing of austenitic welds using ultrasound plays an important role in the assessment structural integrity safety critical structures. internal microstructure these is highly scattering and can lead to obscuration defects when investigated by traditional imaging algorithms. This paper proposes alternative objective method for detection flaws embedded based on singular value decomposition time-frequency domain response matrices. distribution values examined cases where a...

The marriage of welding and Non-Destructive Testing (NDT) processes at the point manufacture has enabled detection correction defects during process. This demonstrated clear financial production benefits by reducing weld rework ensuring schedule certainty, however this is yet to be for use with narrow-groove practises. Narrow-groove welds are notoriously difficult inspect using traditional Phased Array Ultrasonic (PAUT) techniques due large thicknesses vertical nature Lack-of-Sidewall Fusion...

Abstract Estimating the spatially varying microstructures of heterogeneous and locally anisotropic media non-destructively is necessary for accurate detection flaws reliable monitoring manufacturing processes. Conventional algorithms used solving this inverse problem come with significant computational cost, particularly in case high-dimensional, nonlinear tomographic problems, are thus not suitable near-real-time applications. In paper, first time, we propose a framework which uses deep...

On modern manufacturing production lines, Non-Destructive Testing (NDT) is frequently a bottleneck which could greatly be alleviated by integrating the inspection of components as they are manufactured. By moving to point manufacture, greater economic and productivity benefits realised in terms reduced rework schedule slippage, however, new technical challenges emerge. For welded components, high temperatures resulting thermal gradients, present when performing ultrasonic at manufacture. The...

Advances in manufacturing techniques and materials have led to an increase the demand for reliable robust inspection maintain safety critical features. The application of modelling methods develop evaluate inspections is becoming essential tool NDE community. Current analytical are inadequate simulation arbitrary components heterogeneous materials, such as anisotropic welds or composite structures. Finite element analysis software (FEA), PZFlex, can provide ability simulate these...

By definition, a remanufactured product must perform to the same (or higher) level as original product, and therefore be issued warranty of longer) duration. However, many components products will have been subjected regular stresses in their first cycle use may exhibit unseen signs damage at microstructural level. This not affect product's performance initially but could cause it fail before its renewed expires. To combat this, we propose that integrity individual is assessed...

This article considers the propagation of high frequency elastic waves in a layered material. Each layer is locally anisotropic and thicknesses slowness surface orientations are modelled by (Markovian) process. work important deepening our understanding ultrasonic non-destructive testing carbon fibre reinforced polymer (CFRP) composites polycrystalline materials. The paper focuses on monochromatic shear propagating two-dimensional ((x1,x3) plane) heterogeneous media. displacement x2...

Wavefield travel time tomography is used for a variety of purposes in acoustics, geophysics and non-destructive testing. Since the problem non-linear, assessing uncertainty results requires many forward evaluations. It therefore important that evaluation times ray paths efficient, which challenging generally anisotropic media. Given computed field, tracing can be performed to obtain fastest path from any point medium source field. These rays then speed up gradient based inversion methods. We...

Many safety critical structures, such as those found in nuclear plants, oil pipelines and the aerospace industry, rely on key components that are constructed from heterogeneous materials. Ultrasonic non-destructive testing (NDT) uses high-frequency mechanical waves to inspect these parts, ensuring they operate reliably without compromising their integrity. It is possible employ mathematical models develop a deeper understanding of acquired ultrasonic data enhance defect imaging algorithms....

The ability to reliably detect and characterise defects embedded in austenitic steel welds depends on prior knowledge of microstructural descriptors, such as the orientations weld’s locally anisotropic grain structure. These are usually unknown but it has been shown recently that they can be estimated from ultrasonic scattered wave data. However, conventional algorithms used for solving this inverse problem incur a significant computational cost. In paper, we propose framework which uses...

The Marchenko redatuming method estimates surface-tosubsurface Green's functions. It has been employed to diminish the effects of multiples in seismic data. Several such methods rely on an absolute scaling data; this is usually considered be known synthetic experiments, or estimated using heuristic real Here, we show ultrasonic laboratory data that most common these may ill suited task, and reliable ways estimate remains unavailable. which adaptive subtraction therefore more appropriate. We...

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This paper puts forward amethodology for applying the frequencydomain Factorisation Method to time domain experimental data arising from ultrasonic phased array inspections in al imited aperture setting.Application both synthetic and is undertaken am ulti-frequencya pproach explored address difficulty encountered empirically choosing optimum frequencyatwhich operate.Additionally,atruncated singular value decomposition (TSVD)approach implemented case where flawisembedded ahighly scattering...

Traditional imaging algorithms within the ultrasonic NDE community typically assume that material being inspected is homogeneous. Obviously, when medium of a heterogeneous or anisotropic nature this assumption can contribute to poor detection, sizing and characterisation defects. Knowledge internal structure properties would allow corrective measures be taken. The work presented here endeavours reconstruct coarsened maps locally grain industrially representative samples from phased array...

To acquire full matrix capture (FMC) data from an N element array, individual transmissions are required. In cases where the acquisition process is lengthy and expensive (as in laser ultrasonics), it often desirable to reduce overall time by decreasing number of transmissions. Unfortunately, as recording footprint transducer array depleted, our ability image with collected can be hindered. this paper, we present a methodology synthesize reflected at points on inspection surface not covered...

In this paper, we study the inverse problem of recovering spatially varying material properties a solid polycrystalline object from ultrasonic travel time measurements taken between pairs points lying on domain boundary. We consider medium constant density in which orientation material's lattice structure varies piecewise manner, generating locally anisotropic regions wave speed according to incident direction and known slowness curve. This particular is inspired by current challenges faced...

This article considers the propagation of a high-frequency time harmonic, elastic wave in spatially heterogeneous, randomly layered material. The material is locally anisotropic, and properties change from one layer to next by random rotation associated slowness surface plane propagation. thicknesses this follow stochastic (Markovian) process. situation found ultrasonic polycrystalline materials; for example, non-destructive testing welds additively manufactured metallic components. work...

Determining an optimal component design is fundamental to many applications including of those in the aerospace, automotive and civil engineering industries. Previously, compatibility with future non-destructive testing (NDT) requirements has not been considered at stage. As a result, NDT operators are often challenged reliably inspect components complex geometries. In this paper, framework proposed for optimisation component's shape maximise sensitivity coverage interrogating ultrasonic...

Large volume metrology is a key enabler of autonomous precision manufacturing. For component positioning, the optical-based technique photogrammetry could be used more widely if its accuracy was improved. These positional measurements are subject to uncertainties which can greater than manufacturing tolerances. One source uncertainty due thermal gradients, cause refraction light rays in large-scale industrial environments. This paper uses light-based sensor data reconstruct heterogeneous...