scholarly journals METHODOLOGY FOR NON-DESTRUCTIVE IDENTIFICATION OF THICKNESS OF UNILATERALLY ACCESSIBLE CONCRETE ELEMENTS BY MEANS OF STATE-OF-THE-ART ACOUSTIC TECHNIQUES

2013 ◽  
Vol 19 (3) ◽  
pp. 325-334 ◽  
Author(s):  
Krzysztof Schabowicz
Keyword(s):  
Heat Pipe ◽  
State Of The Art ◽  
The State ◽  
Ultrasonic Tomography ◽  
Test Results ◽  
Impact Echo ◽  
Acoustic Techniques ◽  
Concrete Shell ◽  
Concrete Elements ◽  
Non Destructive

The paper presents a methodology for comprehensive use of ultrasonic tomography and impact-echo – the state-of-the-art acoustic techniques – for non-destructive identification of the thickness of unilaterally accessible concrete elements. Since the techniques are not commonly used, they are little known. Therefore, a brief description of the techniques is given to facilitate the understanding of the subsequently presented methodology. The article gives a practical example of the use of the methodology, which demonstrates its suitability for non-destructive identification of the thickness of concrete elements, particularly those only accessible from one side. In the example, the concrete shell of a heat pipe, carrying tunnel located under a river was tested using the ultrasonic tomography and impact-echo techniques. The tests were carried out according to the proposed methodology. It should be noted that the test results yielded by the two methods were similar. In this way, the proposed methodology has been validated.

Non-Destructive Identification of Defects in Power Support Structure Foundations by Means of Acoustic Techniques

2014 ◽  
Vol 606 ◽  
pp. 95-98
Author(s):  
Lukasz Sadowski
Keyword(s):  
Construction Industry ◽  
Support Structure ◽  
Air Voids ◽  
Impact Echo ◽  
Acoustic Techniques ◽  
Location Depth ◽  
Concrete Elements ◽  
Non Destructive ◽  
Made In

Prefabricated power support structure foundations are made in prefabrication plants where concrete is laid in layers in moulds. The quality of the prefabricated units depends mainly on proper concrete mixture compaction, which is usually effected by means of immersion vibrators. It happens that when the vibrator is withdrawn too quickly, defects, in the form of, e.g., air voids and zones of insufficiently vibrated concrete, appear. Modern non-destructive acoustic techniques, which in recent years have been increasingly commonly used in the construction industry, are highly suitable for testing concrete elements, particularly prefabricated concrete units. The non-destructive impact-echo technique is particularly useful for determining defect location depth and for locating defective areas.

scholarly journals Detection of Flaws in Concrete Using Ultrasonic Tomography and Convolutional Neural Networks

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1557 ◽  
Author(s):  
Marek Słoński ◽  
Krzysztof Schabowicz ◽  
Ewa Krawczyk
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Automatic Detection ◽  
Ultrasonic Tomography ◽  
Destructive Testing ◽  
Acoustic Techniques ◽  
Small Set ◽  
Recorded Image ◽  
Concrete Elements ◽  
Non Destructive

Non-destructive testing of concrete for defects detection, using acoustic techniques, is currently performed mainly by human inspection of recorded images. The images consist of the inside of the examined elements obtained from testing devices such as the ultrasonic tomograph. However, such an automatic inspection is time-consuming, expensive, and prone to errors. To address some of these problems, this paper aims to evaluate a convolutional neural network (CNN) toward an automated detection of flaws in concrete elements using ultrasonic tomography. There are two main stages in the proposed methodology. In the first stage, an image of the inside of the examined structure is obtained and recorded by performing ultrasonic tomography-based testing. In the second stage, a convolutional neural network model is used for automatic detection of defects and flaws in the recorded image. In this work, a large and pre-trained CNN is used. It was fine-tuned on a small set of images collected during laboratory tests. Lastly, the prepared model was applied for detecting flaws. The obtained model has proven to be able to accurately detect defects in examined concrete elements. The presented approach for automatic detection of flaws is being developed with the potential to not only detect defects of one type but also to classify various types of defects in concrete elements.

Model Testing for Vortex Induced Motions of Spar Platforms

2004 ◽  
Author(s):  
Mehernosh Irani ◽  
Lyle Finn
Keyword(s):  
Gulf Of Mexico ◽  
Model Test ◽  
State Of The Art ◽  
Model Testing ◽  
Model Tests ◽  
The State ◽  
Test Results ◽  
Test Set ◽  
Vortex Induced Vibrations ◽  
Set Up

The state-of-the art in model testing for Vortex Induced Vibrations (VIV) of Spars is presented. Important issues related to Spar VIV model testing are highlighted. The parameters that need to be modeled including hull geometry, strake configuration, mass and mooring properties and, considerations of test set-up and instrumentation are discussed. Results are presented from model tests of an as-built Spar deployed in the Gulf of Mexico. It is shown that the model test results compare well with the VIV responses measured in the field.

scholarly journals Non-destructive Testing of Wooden Elements

2021 ◽  
Vol 1203 (3) ◽  
pp. 032058
Author(s):  
Monika Zielińska ◽  
Magdalena Rucka
Keyword(s):  
Surface Defects ◽  
Test Methods ◽  
Ultrasonic Tomography ◽  
Test Results ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Near Surface ◽  
Thermal Techniques ◽  
Ground Penetrating ◽  
Non Destructive

Abstract Examining the condition of wooden elements is crucial from the perspective of proper structure performance. If the deterioration in the internal wood condition, which displays no symptoms visible from the outside, is detected, the further spread of the deterioration can be prevented. Test results often point to the necessity of conducting repairs and, renovations, replacing the structure of wooden beams, or even substituting a significant part of the structure. To achieve acceptable results, test methods should take into account the anisotropic nature of wood, which includes the shape of annual rings, as well as the location of the core in crosssection. To adopt methods based on physical effects, profound knowledge of wood physics is needed, particularly of interdependence. Apart from simple tests such as a visual inspection or tapping that are used to determine near-surface defects, non-destructive testing (NDT) plays an important role in the process. This paper presents the methods of non-destructive testing of wooden elements. These methods include tests conducted with ground penetrating radar (GPR), thermal techniques, microwaves, acoustic emission, ultrasonic tomography, and X-ray tomography. The paper summarises the use of non-destructive methods, indicating their advantages, disadvantages as well as some limitations.

A Review of Acoustic Emission Technique for Machinery Condition Monitoring: Defects Detection & Diagnostic

2012 ◽  
Vol 229-231 ◽  
pp. 1476-1480 ◽  
Author(s):  
Salah M. Ali Al-Obaidi ◽  
M. Salman Leong ◽  
R.I. Raja Hamzah ◽  
Ahmed M. Abdelrhman
Keyword(s):  
Acoustic Emission ◽  
Condition Monitoring ◽  
State Of The Art ◽  
The State ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Acoustic Emission Technique ◽  
Destructive Testing ◽  
Machinery Condition Monitoring ◽  
Non Destructive

Acoustic emission (AE) measurements are one of many non-destructive testing methods which had found applications in defects detection in machines. This paper reviews the state of the art in AE based condition monitoring with particular emphasis on rotating and reciprocating machinery applications. Advantages and limitations of the AE technique in comparison to other condition monitoring techniques in detecting common machinery faults are also discussed.

EXTRA-TN: A novel approach for an extended resilience analysis of transport networks

2020 ◽  
Author(s):  
Fabrizio D'Amico ◽  
Chiara Ferrante ◽  
Luca Bianchini Ciampoli ◽  
Alessandro Calvi ◽  
Andrea Benedetto
Keyword(s):  
Data Fusion ◽  
Ground Penetrating Radar ◽  
State Of The Art ◽  
The State ◽  
Transport Infrastructure ◽  
Actual Condition ◽  
Actual State ◽  
Transport Networks ◽  
Ground Penetrating ◽  
Non Destructive

<p>Recent and dramatic events occurred on the Italian transport networks have pointed out the urgent need for assessing the actual state of health along the national transport assets. Analogous considerations can be addressed towards the high exposition and vulnerability of the transport system to major natural events, such as floods or earthquake.</p><p>Recently, the administrations and managing companies have increasingly made use of non-destructive techniques for achieving a denser knowledge about the health of the asset.</p><p>However, one of the major limitations concerning these methods is that each technology, according to its specific features, is usually suitable for a single specific application and has very limited effectiveness for other tasks. Accordingly, the integration of datasets collected with different NDTs stands as a viable approach to fill technology-specific gaps, thereby ensuring a more comprehensive assessment of the infrastructure [1-3]. Data fusion logic can also potentially allow for further data interpretation from merging different information [4].</p><p>The EXTRATN project aims at overcoming the state-of-the-art research in the field of non-destructive monitoring of linear infrastructures and, through a “data fusion” logic, at achieving a comprehensive rate of knowledge about the actual condition of the asset. The addressed concept is a “fully sensed infrastructure”, being sensed by different technologies and with different scopes. Specifically, interferometric synthetic aperture radar (DInSAR), Laser Imaging Detection and Ranging (LiDAR), Ground-penetrating Radar (GPR) and Falling Weight Deflectometer (FWD) are considered to the purpose.</p><p>A system of transport infrastructure being located in the Province of Salerno (IT), within an area subjected to hydrogeological risk, has been selected as a study case for the integrated approach. This system includes a motorway, a rural highway and a railway.</p><p>As a major advantage with respect to the state-of-the-art, such a methodology allows for analysing the evolution trend of the on-going distresses, meaning a significant upgrade of the monitoring activities that may provide valuable information for a priority-based scheduling of the maintenance.</p><p>Moreover, such an approach enables to simultaneously monitor exogenous and endogenous events that may lead to a decrease of the safety, functionality or strength conditions.</p><p>The research is supported by the Italian Ministry of Education, University and Research under the National Project “Extended resilience analysis of transport networks (EXTRA TN): Towards a simultaneously space, aerial and ground sensed infrastructure for risks prevention”, PRIN 2017, Prot. 20179BP4SM.</p><p> </p><ol><li>Liu W, Chen S, Hauser E (2011) LiDAR-based bridge structure defect detection. Exp Tech 35(6):27–34.</li> <li>Grasmueck M, Viggiano DA (2007) Integration of ground-penetrating radar and laser position sensors for real-time 3-D data fusion. IEEE Trans Geosci Remote Sens 45(1):130–137.</li> <li>Solla M et al (2011) Non-destructive methodologies in the assessment of the masonry arch bridge of Traba, Spain. Eng Fail Anal 18(3):828–835</li> <li>Luo RC, Yih C-C, Su KL (2002) Multisensor fusion and integration: approaches, applications, and future research directions. IEEE Sens J 2(2):107–119.</li> </ol>

Advanced Ultrasonic Testing Technologies with Applications to Evaluation of Steel Bridge Welding - An Overview

2015 ◽  
Vol 727-728 ◽  
pp. 785-789 ◽  
Author(s):  
Zhi Bin Lin ◽  
Fardad Azarmi ◽  
Qusay Al-Kaseasbeh ◽  
Mohsen Azimi ◽  
Fei Yan
Keyword(s):  
Quality Control ◽  
Ultrasonic Testing ◽  
State Of The Art ◽  
Flaw Detection ◽  
Steel Bridges ◽  
The State ◽  
Steel Bridge ◽  
Non Destructive Evaluation ◽  
Non Destructive ◽  
The Way

Non-destructive evaluation (NDE) methods are widely accepted for quality control of welding in steel bridges. Recent development of advanced ultrasonic testing technologies enriched the categories of NDE methods used for steel bridges and more importantly these enhanced techniques provided more effective flaw detection and characterization. No guidelines, however, is available in existing bridge welding code for their more widespread applications to bridges. In this study, we overview the state-of-the-art advanced ultrasonic testing technologies in welding inspection. Benefits of the enhanced ultrasonic testing technologies are summarized, aiming to pave the way for deciding methods need for various steel bridge welding inspections.

scholarly journals A Review of the State-of-Art, Limitations, and Perspectives of Machine Vision for Grape Ripening Estimation

2021 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Eleni Vrochidou ◽  
Christos Bazinas ◽  
George A. Papakostas ◽  
Theodore Pachidis ◽  
Vassilis G. Kaburlasos
Keyword(s):  
Machine Vision ◽  
State Of The Art ◽  
The State ◽  
Wine Industry ◽  
Ripening Stage ◽  
Robotic Automation ◽  
Non Destructive ◽  
State Of Art ◽  
Destructive Methods ◽  
Critical Aspects

This work highlights the most recent machine vision methodologies and algorithms proposed for estimating the ripening stage of grapes. Destructive and non-destructive methods are overviewed for in-field and in-lab applications. Integration principles of innovative technologies and algorithms to agricultural agrobots, namely, Agrobots, are investigated. Critical aspects and limitations, in terms of hardware and software, are also discussed. This work is meant to be a complete guide of the state-of-the-art machine vision algorithms for grape ripening estimation, pointing out the advantages and barriers for the adaptation of machine vision towards robotic automation of the grape and wine industry.

scholarly journals COMPARISON OF CONCRETE COMPRESSIVE STRENGTH VALUES OBTAINED USING REBOUND HAMMER AND DRILLED CORE SPECIMENS

2015 ◽  
Author(s):  
Raimondas SADZEVICIUS ◽  
Tatjana SANKAUSKIENE ◽  
Petras MILIUS
Keyword(s):  
Reinforced Concrete ◽  
Concrete Strength ◽  
Hydraulic Structures ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Main Attention ◽  
Concrete Core ◽  
Rebound Hammer ◽  
Concrete Elements ◽  
Non Destructive

Durability of reinforced concrete structures depends on the maintenance conditions, surveillance, and well-timed repair of structures or reconstructions. Usually, the main attention falls on the durability determination based on the evaluation of change of main physical –mechanical properties, especially, on the compression strength of concrete. In this study, tests with the rebound hammer and concrete cores extracted from the existing reinforced concrete elements in hydraulic structures are presented. The comparison of strength values obtained with the rebound hammer and the concrete core specimens of reinforced concrete in hydraulic structures is carried out. The research was performed during the scientific expedition in the period of 2010–2014. The investigated objects are allocated in hydroschemes of Druskininkai, Marijampolė, Klaipėda districts. It was established that the results obtained using the non-destructive method were by 17 % higher than the ones obtained by performing the destructive test. However, it can be said that despite this fact, the non-destructive method offers simplicity and rapidity in use: test results are readily available on site and there is a possibility to test concrete strength of those structures where cores cannot be drilled due to thin-walled or densely reinforced structures.

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