Evaluation of UT Wall Thickness Measurements and Measurement Methodology

Weier, Dennis R.; Pardini, Allan F.

doi:10.2172/1035013

Cited by 5 publications

(5 citation statements)

References 2 publications

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“…In both trials, mean error approached the theoretical thickness resolution limit of 0.032 mm given by the instrumentation sampling rate and speed of sound in aluminum. Accuracy was within the ±0.5 mm reported for typical in situ manual thickness gauging [26], [27].…”

Section: 𝑑 = 𝑣𝑡 𝑛 ⁄ (1)supporting

confidence: 61%

Deployment of Contact-Based Ultrasonic Thickness Measurements Using Over-Actuated UAVs

Watson

Pierce

Kamel³

et al. 2021

Lecture Notes in Civil Engineering

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Unmanned Aerial Vehicles (UAVs) are increasingly being utilized for the structural health assessment of on and off-shore structures. Visual inspection is the usual methodology for acquiring data from these structures, but there is often a need for contact based structural measurements, for example to assess local thickness on corroding structures. Conventional UAV platform dynamics have not traditionally allowed for such contact measurements. The limited dynamic control afforded by fixed plane rotor UAVs means that forward thrust (to apply contact forces for surface transduction) is only possible by tilting the whole platform, thus taking the UAV into a non-stationary state and limiting positional accuracy. An over-actuated UAV platform (with fully vectored thrust capability) may provide the required contact force for such thickness measurements whilst maintaining stable hovering next to the structure. The authors herein present a contact based ultrasonic thickness measurement technique, whereby an ultrasonic wheel probe deployed from a UAV was used to make single point and scanned measurements across a surface to provide a set of local thickness measurements. A 5MHz, dry-coupled, dual-element, ultrasonic wheel probe is used to measure the thickness of an aluminum sample plate with thicknesses of 8.2 mm, 4.5 mm and 3.2 mm, and a precision stepped calibration block with size from 31.5 mm to 17.5 mm in steps of 1 mm, then steps of 0.1mm down to 16.5 mm over a total length of 500 mm. The thickness resolution obtainable from the ultrasonic wheel probe was typically 0.1 mm, and the positional accuracy attained from the overactuated deployment platform was 16.6 mm when performing single point measurements.

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Section: 𝑑 = 𝑣𝑡 𝑛 ⁄ (1)supporting

confidence: 61%

Deployment of Contact-Based Ultrasonic Thickness Measurements Using Over-Actuated UAVs

Watson

Pierce

Kamel³

et al. 2021

Lecture Notes in Civil Engineering

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“…The plate thickness error values noted above are clearly far away from the currently accepted convention of approximate accuracy limits (±0.002mm) when using modern equipment, manually scanned and calibrated for parameters such as cable lengths, temperature and surface properties [60]. However the values, shown in Table 7 are broadly aligned with the practical accuracy values of ±0.5mm, found in typical similar scenario manual inspections [61][62][63]. This is encouraging considering the automated aspect of the measurement and its relative > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < infancy.…”

Section: ) Nde Resultsmentioning

confidence: 67%

Machining-Based Coverage Path Planning for Automated Structural Inspection

MacLeod

Dobie

Pierce

et al. 2018

IEEE Trans. Automat. Sci. Eng.

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The automation of robotically delivered Non Destructive Evaluation (NDE) inspection shares many aims with traditional manufacture machining. This paper presents a new hardware and software system for automated thickness mapping of large-scale areas, with multiple obstacles, by employing CAD/CAM inspired path planning to implement control of a novel mobile robotic thickness mapping inspection vehicle. A custom post-processor provides the necessary translation from CAM Numeric Code through to robotic kinematic control to combine and automate the overall process. The generalised steps to implement this approach for any mobile robotic platform are presented herein and applied, in this instance, to a novel thickness mapping crawler. The inspection capabilities of the system were evaluated on an indoor mock-inspection scenario, within a motion tracking cell, to provide quantitative performance figures for positional accuracy. Multiple thickness defects simulating corrosion features on a steel sample plate were combined with obstacles to be avoided during the inspection. A minimum thickness mapping error of 0.21 mm and mean path error of 4.41 mm were observed for a 2 m 2 carbon steel sample of 10 mm nominal thickness. The potential of this automated approach has benefits in terms of repeatability of area coverage, obstacle avoidance and reduced path overlap, all of which directly lead to increased task efficiency and reduced inspection time of large structural assets. Note to Practitioners-Current industrial robotic inspection approaches largely consist of manual control of robotic platform motion to desired points, with the aim of producing an number of straight scans for larger areas, often spaced meters apart. Structures featuring large surface area and multiple obstacles, are routinely inspected with such manual approaches, which are both labour intensive, error prone and do not guarantee acquisition of full area coverage. The presented system addresses these limitations through a combined hardware and software approach. Core to the operation of the system is a fully wireless, differential drive crawler with integrated active ultrasonic wheel probe, to provide remote thickness mapping. Automation of path generation algorithms is produced using commercial CAD/CAM software algorithms, and this paper sets out an adaptable methodology for producing a custom post-processor to convert the exported G-Codes to suitable kinematic commands for mobile robotic

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“…But after the several tanks were so inspected during 2007, more multiple riser results became available. For the analysis of riser differences from those 2007 tanks, riser differences were not indicated (see Weier, Pardini 2007). This led to the consideration for reducing inspections from two paths from each of two risers to perhaps three or four paths from a single riser.…”

Section: Riser Differencesmentioning

confidence: 99%

Ultrasonic Examination of Double-Shell Tank 241-AW-106 Examination Completed July 2009.

Pardini¹,

Weier²,

Anderson³

et al. 2009

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AREVA Federal Services LLC (AFS), under a contract from Washington River Protection Solutions (WRPS), has performed an ultrasonic examination of selected portions of Double-Shell Tank 241-AW-106. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-AW-106 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plan (ETP), RPP-Plan-38332 (Castleberry 2008) and summarized on page 1 of this document, are to be reported to WRPS and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with WRPS, all data is to be recorded on electronic media and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report(s) that describes the results of the AFS ultrasonic examinations. Examination ResultsThe results of the examination of Tank 241-AW-106 have been evaluated by PNNL personnel. The ultrasonic examination consisted of two vertical 15-in.-wide scan paths over the entire height of the tank from Riser 28. The examination also included two vertical 15-in.-wide scan paths over the entire height of the tank and the heat-affected zone (HAZ) of four vertical welds and one horizontal weld from Riser 29. The examination was performed to detect any wall thinning, pitting, or cracking in the primary tank wall.

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Evaluation of UT Wall Thickness Measurements and Measurement Methodology

Cited by 5 publications

References 2 publications

Deployment of Contact-Based Ultrasonic Thickness Measurements Using Over-Actuated UAVs

Deployment of Contact-Based Ultrasonic Thickness Measurements Using Over-Actuated UAVs

Machining-Based Coverage Path Planning for Automated Structural Inspection

Ultrasonic Examination of Double-Shell Tank 241-AW-106 Examination Completed July 2009.

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