Table of Contents 276 Articles in Issue: 2018-11 | |
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Exhibitors (18) | |
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Title / Author(s) / Keywords
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Publication |
 PAUT and Conventional Modality for the Materials Characterization using Frequency Domain Signal Presentation (FFT) Sonotron NDT 70, Rehovot, Israel
NEWS
| NDT.net Journal
|  Toggling between S-Scan and FMC/TFM coverage whilst inspecting simple and complex geometry welds and other structural elements Sonotron NDT 70, Rehovot, Israel
NEWS
| NDT.net Journal
|  The FlexoFORM™ Scanner Provides a Complete Ultrasonic Testing Solution for Corrosion Inspection of Pipe Elbows Olympus Scientific Solutions Americas (OSSA) 230, Waltham, MA, USA NEWS
| NDT.net Journal
|  Sonatest is proud to deliver its new generation of the popular RapidScan product family the RSflite Sonatest Ltd 44, Milton Keynes, United Kingdom NEWS
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|  Innerspec launches new line of Ultrasonic Thickness Gauges without contact and couplant Innerspec Technologies 14, Lynchburg, Virginia, USA NEWS
| NDT.net Journal
|  Introducing the multiple-angle TOFD wedge Innovation Polymers 6, Kitchener, Ontario, Canada NEWS
| NDT.net Journal
|  Rugged and Reliable – The new DRC 2430 NDT Mobile High-Resolution Flat Panel Detector Dürr NDT GmbH Co.KG 17, Bietigheim-Bissingen, Germany NEWS
| NDT.net Journal
|  Automatic for a Perfect Image InfraTec GmbH 35, Dresden, Germany NEWS
| NDT.net Journal
|  Zetec to Present Webinar on the Latest Advanced Focusing Techniques for Phased Array Ultrasonic Inspections Zetec 84, Snoqualmie, WA, USA NEWS
| NDT.net Journal
|  TESTIA, an Airbus Company under the spotlight at Air Convention TESTIA France 34, Toulouse, France NEWS
| NDT.net Journal
|  InFactory now part of TESTIA TESTIA France 34, Toulouse, France NEWS
| NDT.net Journal
|  Live CT scans at the Museum für Naturkunde Berlin YXLON International GmbH 196, Hamburg, Germany
NEWS
| NDT.net Journal
|  Two Global Technology Awards for Yxlon YXLON International GmbH 196, Hamburg, Germany NEWS
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|  SITAU TRITON: High Speed Ultrasound Inspection System for Complex Geometry Composites Dasel S.L. 10, Arganda del Rey, Madrid, Spain NEWS
| NDT.net Journal
|  Tube India 2018 – Inspection, Testing & Quality Control Controle Mesure Systemes (CMS) 12, La Charmee, France NEWS
| NDT.net Journal
|  Robot-assisted sensor system for quality assurance of press-hardened components Fraunhofer-Institute for Non-Destructive Testing (IZFP) 475, Saarbrücken, Germany NEWS
| NDT.net Journal
|  ZfP-Zeitung Ausgabe 161 Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) 160, Berlin, Germany NEWS DE
| NDT.net Journal
| Feasibility of Detection of Leaking Fuel Rods Using Side Coupled Guided Waves Sergey VINOGRADOV, John BEALE, Byungsik YOON Nuclear fuel rods, side coupled guided waves, pinhole, magnetostrictive transducer
Close
Fuel rods in nuclear reactors consist of uranium fuel pellets that are encased in hollow metal tubes made from zirconium alloys. Due to the elevated temperature, pressure, and radiation inside of a reactor, fuel rods can fail during operation. The most common failure mechanism in Pressurized Water Reactors (PWRs) is grid-to-rod fretting wear while for Boiling Water Reactors, debris fretting is most common. Other mechanisms include crud and corrosion failures, and pellet cladding interaction cracks. The failure of a fuel rod can potentially lead to leaking of radioactive material into the primary coolant system. Identifying the individual leaking fuel rod presents a challenge. A magnetostrictive transducers and guided wave technology have been investigated recently with the focus on detection of through wall anomalies such as axial, skewed, circumferential notches and drilled holes. A probe coupled from the top of the rod was used. Due to the fact that the access to the fuel rods might be more practical from the side, a side coupling probe was developed in addition to the top coupling probe. The side coupling probe has gone through a number of evaluations and modifications with the major goal of improving its sensitivity to a pinhole type of defects. Fundamental T(0,1) guided wave mode at frequency range 100 - 350 kHz was used during tests. The probe design and results of mockup tests with known artificial anomalies will be discussed.
| NDT.net Journal
| Modular Bayesian damage detection for civil structures. A proof of concept case-study A. Jesus1 4, P. Brommer1, R. Westgate2 2, K. Koo2 2, J. Brownjohn2 5, I. Laory1 4 1aSchool of Engineering, Civil Research Group bSchool of Engineering, Warwick Centre for Predictive Modelling; University of Warwick 51, Coventry, United Kingdom 2College of Engineering, Mathematics and Physical Sciences; University of Exeter 5, Exeter, United Kingdom Electromagnetic Testing (ET), Magnetic Testing (MT), Other Methods, Structural Health Monitoring, Bayesian system identification, Damage detection and localization, bridge monitoring, Gaussian process
Close
In the last decades, a significant portion of research in Structural Health Monitoring has been developed upon the principles of vibration-based methods, where monitored modal properties have been treated as a set of features for damage detection. Unfortunately, factors external to the structural system, such as environmental\slash operational effects, have been shown to mask relevant anomalous patterns. This paper presents a modular Bayesian damage identification framework which considers external effects explicitly, along with other sources of uncertainty. A calibrated finite element model of the Tamar bridge is used in order to identify anomalous features in the bridge main\slash stay cables and its bearings. Displacements, natural frequencies, temperature and traffic monitored throughout one year are used to form a reference baseline, which is compared against a posterior identification with one month of monitored data. The proposed framework allows to account for observation errors, estimation of damage and model discrepancy of the predictive model. Multiple response Gaussian processes emulate the model response surface and its discrepancy enhancing the identification task while minimising costly computations. Results indicate that the main cables and bearings have no structural defects. Although the stay cables strain increased considerably, this could be attributed to the inherent variability of their properties. Finally, a considerable amount of uncertainty is propagated when estimating the proposed damage metric, and some options to reduce it are discussed.
| EWSHM 2018 Session: SHM in Civil Engineering | Improved signal processing of Acoustic Emission for Structural Health Monitoring using a data-driven approach S. Wirtz 5, D. Söffker 16 Chair of Dynamics and Control; University of Duisburg-Essen 17, Duisburg, Germany Acoustic emission, Composite materials, Data processing, Defects, Detection systems
Close
Extracting isolated signal patterns from continuously sampled data and discarding noise is of particular importance in the field of Structural Health Monitoring. Using Acoustic Emission (AE) for passive in-situ inspection, this is considered as a challenging task. Here, ultrasound stress waves are recorded passively to detect damage occurring in a material or structure in real-time. The corresponding waveforms recorded by AE transducers carry information regarding their underlying source mechanism, which can be related to either damage or spurious noises from the environment. Typically, these signals are transient and stochastically distributed in time. Many state-of-the-art AE systems use fixed thresholds to distinguish between relevant signals and noise. However, in practical applications these approaches are inaccurate or even unfeasible due to low signal-to-noise ratio. In this paper, a data driven approach to distinguish between relevant signals and noise is presented. To identify a model from the AE data Platt calibration is used, which was developed to map the output of support vector machines to probabilities. The advantage of this approach is that the mapping between signal characteristics and relevance can be derived from preliminary measurements such as Pencil-Lead Break (PLB) test. In a first step, the distance of the measurements to a baseline is computed. Furthermore, by determining the onset of the PLB signal manually or using a different method such as Akaike information criterion, the measurement can be split in two disjoint sections containing the relevant signal and noise, respectively. Finally, a parametric model is derived from the obtained class-conditional distributions of distances using a curve fitting procedure. Based on this model a characteristic function which serves as a probabilistic measure indicating the presence of relevant signals can be computed. The feasibility of the approach is demonstrated using AE measurements from indentation tests of composite plates.
| EWSHM 2018 Session: Acoustic Emission |
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