In-service Testing Research Articles

Development of an in-service NDT system for storage tanks

The large storage tank is one of the major infrastructures. Once a leak occurs, it often causes environmental pollution and even catastrophic accidents. In the early years, the method of emptying tanks and cutting plates for defects inspection was adopted to avoid leakage. However, there exist some deficiencies such as large blindness, long downtime and high cost. Since there are many problems in the traditional testing, inspection without emptying the tank and without stopping production is an indispensable technical means to ensure the safe operation of the tank. An in-service non-destructive testing (NDT) system for storage tanks without emptying is developed in this paper, which mainly includes sensors, the signal processing module, the testing crawler, the winding and releasing mechanism and control module et. al. The sensors, signal processing module and testing crawler need to be placed into the tank from the roof man-hole by the crane, while the control module is located outside the tank. The sensor can realize the combined inspection of magnetic field leakage (MFL) and electromagnetic acoustic transducer (EMAT). The laboratory experiments indicate that the system can realize in-service inspection of the corrosion defects on the bottom and works well in water. The new testing system will overcome the shortage of off-line service inspection methods that emptying and cleaning tanks are needed before inspection and environmental risks are involved. These research works guarantee the safe operation of storage tanks and provide an alternative NDT system for storages related industrial projects.

Eddy current nondestructive evaluation of metallic plates electrical conductivity using artificial neural networks based inverse problem

The most used method and extensively studied in the literature for conductors’ characterization is Eddy Current Nondestructive Evaluation (ECNDE) due to its significant advantages, such as its ability to preserve the integrity of the structures or materials to be examined during manufacturing or a regular in-service nondestructive testing. Various approaches are developed for the Eddy Current measurement of the electrical conductivity. In the present work, the evaluation of the electrical conductivity is treated as an inverse problem. In pursuit of this aim, a combination is established between Eddy currents evaluation and artificial neural networks (ANN) to evaluate the electrical conductivity of homogeneous metallic plates from eddy-current probe impedance measurements. For this purpose, an experimental setup is developed, including a bobbin-coil probe, metallic plates (target), data acquisition and signal processing systems. Finally, experimental conductivity values of various metallic plates using ANN are compared with those obtained using four-point measurements of direct current potential drop (DCPD) made on the same plates and very good agreement is obtained.

An observational objective job analysis of role related tasks undertaken by Royal Navy sailors.

The current in-service Royal Naval Fitness Test has two elements to test the aerobic endurance and muscular strength of Service Personnel through generic field-based tests and a short job task simulation. However, in 2017 the Royal Navy (RN) identified a requirement to update their in-service fitness test to align with international best practice. The purpose of this study was to conduct an Objective Job Task Analysis on critical, physically demanding tasks that could be undertaken by RN sailors during sea deployments. Twenty-one training exercises were observed across a range of contexts; Type 23 Frigates, Type 45 Destroyers and at shore-based training facilities. A total of 203 RN personnel (age 27.8±7.1 years) were observed undertaking 36 job related tasks (e.g., 'firefighting', 'damage control', 'abandon ship' and 'casualty handling'). Tasks were evaluated by cardiovascular response, primary functional movements and contextual factors to aid a Military Judgement Panel in task list down-selection. 14 Criterion Tasks (e.g., 'firefighting', 'two-person magazine stowage' and 'casualty handling') were selected to progress to the next stage of the process. Five tasks were selected based on cardiovascular responses and a further nine tasks selected based on task ergonomics and other factors. This research has identified and quantified the most physically demanding, critical roles undertaken by RN sailors on sea deployments and will inform the development of the RN Physical Employment Standard.

Comparing Graduating Plastic Surgery Residents' Case Logs With Accreditation Council for Graduate Medical Education Requirements, Content at National Meetings, and In-Service Examination Test Items.

The importance of adaptable and up-to-date plastic surgery graduate medical education (GME) has taken on new meaning amidst accelerating surgical innovation and increasing calls for competency-based training standards. We aimed to examine the extent to which the procedures plastic surgery residents perform, as represented in case log data, align with 2 core standardized components of plastic surgery GME: ACGME (Accreditation Council for Graduate Medical Education) minimum procedure count requirements and the PSITE (Plastic Surgery In-Service Training Examination). We also examined their alignment with procedural representation at 2 major plastic surgery meetings. Nine categories of reconstructive and aesthetic procedures were identified. Three-year averages for the number of procedures completed in each category by residents graduating in 2019-2021 were calculated from ACGME national case log data reports. The ACGME procedure count minimum requirements were also ascertained. The titles and durations of medical programming sessions scheduled for Plastic Surgery The Meeting (PSTM) 2022 and the Plastic Surgery Research Council (PSRC) Annual Meeting 2022 were retrieved from online data. Finally, test items from the 2020 to 2022 administrations of the PSITE were retrieved. Conference sessions and test items were assigned to a single procedure category when possible. Percent differences were calculated for comparison. The distribution of procedures on plastic surgery resident case logs differs from those of the major mechanisms of standardization in plastic surgery GME, in-service examination content more so than ACGME requirements. Meeting content at PSTM and PSRC had the largest percent differences with case log data, with PSTM being skewed toward aesthetics and PSRC toward reconstructive head and neck surgery. The criteria and standards by which plastic surgery residents are evaluated and content at national meetings differ from the procedures they actually complete during their training. Although largely reflecting heterogeneity of the specialty, following these comparisons will likely prove useful in the continual evaluation of plastic surgery residency training, especially in the preparation of residents for the variety of training and practice settings they pursue.

Tracing the regulated emissions of field-aged gasoline/natural gas bi-fuel taxis from new to 160,000 km: Deterioration and environmental implications

Natural gas (NG) is considered an economically viable transport decarbonization option, especially for developing countries. However, as per the ongoing European and Chinese vehicle emission regulations, the durability and in-service compliance tests of the exhaust emissions from gasoline/NG bi-fuel vehicles are only mandated in gasoline mode, leaving the real-world emission performance of NG fueling at risk. To bridge this gap, the exhaust emissions from five gasoline/NG bi-fuel taxis were traced from new (less than 10,000 km) to 160,000 km after every 10,000 km of field driving. Both room-temperature cold-start and warm-start chassis dynamometer tests were performed over the certification drive cycle. This tracing study lasted for 3.5 years and covered the variations of seasons, routine services, and minor repairs. The results manifested that compared to gasoline fueling, NG had statistically lower carbon monoxide before 100,000 km of driving but higher total hydrocarbon and nitrogen oxides emissions throughout the useful life in both cold- and warm-start tests. By applying linear regression to the data points obtained across the 160,000 km tracing, NG fueling showed a noticeably quicker deterioration with mileage than gasoline. However, given that gasoline and NG modes shared the same catalysts, this is attributed to the less careful calibration of NG mode predominantly because of the void of regulatory requirements. On average, NG fueling produced about 20 % less carbon dioxide emissions than gasoline, but the observed fuel leakage in NG mode partially offset the global warming potential advantage. Overall, NG sees benefits and challenges in mitigating vehicle-related environmental issues. To better control this risk, it is strongly recommended that in future regulations, the durability and in-service compliance requirements of NG fueling shall be complemented, and fuel leakage shall be included in the control of evaporative emissions.

Ultrasonic testing through a thickened cladding

This paper presents the results of studies of the effect of thickened repair anti-corrosion surfacing on pre-operational and in-service ultrasonic testing (UT) of the reactor vessel metal through anti-corrosion cladding in comparison with ultrasonic testing through standard surfacing provided for by the design documentation [1]. The paper estimates the distortion of acoustic fields of transducers of transverse and longitudinal waves and the detectability of defects during ultrasonic testing through cladding of different thicknesses and cladding with an inclined fusion zone from a thickness of 11 mm to a thickness of 18 mm

Influence of tensile stress on the magnetic flux leakage signal of the coated steel belt

ABSTRACT The safety of coated steel belts (CSBs) is crucial for reliable elevator operation, as they are critical components in elevator systems. Magnetic flux leakage (MFL) testing is the preferred non-destructive method for evaluating CSBs due to its high sensitivity. Previous studies overlooked tensile stress's impact on in-service MFL testing of CSBs, potentially resulting in inaccurate defect assessments. This research aims to investigate the impact of tensile stress on the MFL signal of CSBs by developing a theoretical model, conducting finite element simulations, and performing experimental verification. In this paper, the rectangular edge defects are considered as the primary defect type in CSBs, and the applied stress on the CSBs varies from 30 MPa to 160 MPa. Under the above conditions, a linear relationship between MFL signal of CSBs and stress is established based on the simplified Jiles-Atherton model and magnetic dipole model suitable for CSBs. The finite element simulation and experiments further indicate that the MFL signal of CSBs increases linearly with the increasing tensile stress. The primary contributions of this study are establishing an MFL model suitable for CSBs and uncovering the linear relationship between the MFL signal of CSBs and tensile stress.

Loading test on the oil tank ground settlement performance monitored by an optical parallel scheme.

A loading test of the ground settlement (GS) performance of the oil tank must be examined before beginning its commercial service. This test requires the sensors to be installed around the oil tank, and the GS is measured while water is being filled in, where the liquid level is read with an ultrasonic radar equipment, etc., to indicate the applied water loads. During the service of the oil tank, loading and unloading corresponding to the oil inlet and outlet are the critical factors to cause the oil tank destruction in a fatigue way. Thus, a regular in-service loading test is the means of evaluating the tank base health condition. However, the sensors for GS measurement of the oil tank are mostly based on a liquid hydraulic sensor, which is an intrinsically static sensor determined by the fluidity of the measurement liquid. In order to meet the instantaneous requirement of the loading test, first, the configuration of the optical GS sensor was designed to suit the simultaneous measurement. Secondly, a data acquisition system was designed by combining the digital signal processing with a field programmable gate array to carry out a parallel multiple channel data collection. This ensures that the GS sensors are interrogated simultaneously to snapshot a GS status of the oil tank, even if its load was changed slowly. A practical oil inlet process was recorded with an ultrasonic radar oil level measurement, and the results of oil tank GS were verified with a manual measurement by using the Electronic Total Station. The effectiveness of our sensor monitoring of the oil tank GS performance during the loading test has been proven.

14. Is Plastic Surgery Resident Learning and Assessment Consistent? A Comparison of American Society of Plastic Surgery Educational Network topics, In-Service Examinations, and Residency Core Curriculums

Background: The in-service exam is the only objective measure to compare plastic surgery (PS) residents’ knowledge. Yet, there is an ongoing debate surrounding the correlation of the test to a plastic surgeon’s success. The American Society of Plastic Surgeons (ASPS) has created an Education Network (EdNet) with an in-depth curriculum, deemed a “gold standard” on which many programs model their academic didactic sessions. However, no analysis has investigated how well the in-service examination, EdNet, and core curricula across residency programs align. This study aims to quantify differences between critical PS learning modalities to inform a more unified education plan for residents. Methods: EdNet questions, accessed through ASPS, corresponding to each course subcategory were tabulated. Next, two independent reviewers and a third arbitrator assigned each question from the 2018-2022 in-service exams to the EdNet subcategories. Finally, the curriculums for fifteen residency programs were obtained, and didactics for each curriculum were assigned to EdNet subcategories. Alignment between core curricula, in-service exam questions, and EdNet resident courses was tested with Pearson’s Chi-Square and Fisher’s Exact Tests. Results: 102 EdNet subcategories were identified, corresponding to nine major courses. 2,038 questions exist across all resident courses. 1170 in-service questions and 910 didactics were assigned to EdNet subcategories. Program core curricula taught thirty subcategories at significantly different frequencies than those presented in EdNet courses. The past five in-service examinations tested 28 subcategories at significantly different frequencies than those taught in the EdNet courses. Conclusion: This study helps answer two questions in PS resident education: do programs teach, and does the in-service exam test, the gold standard? The answer, in both cases, is “somewhat,” as nearly one-third of gold standard subcategories are taught and tested at significantly different frequencies. The gold standard may also require review. For example, while anatomy courses exist for the breast and trunk, none exist for the head and neck or extremities. Similarly, EdNet does not dedicate a category to lymphedema. Therefore, there is significant room to further align teaching and standardized testing in PS education to improve resident learning and better assess resident knowledge.

The Role of In-Service Pavement Studies on the German Highway Network in the Innovation Process

Innovations in the road construction sector are key to tackling the major challenges that the transport infrastructure sector is currently facing. In-service pavement studies (ISPS) are a vital component of the innovation process in the highway infrastructure sector. This paper defines the role of ISPS in the innovation process of the German highway construction sector and identifies suitable criteria to assess and evaluate the innovation characteristics of the in-service test tracks. In conclusion it provides generalisable recommendations how ISPSs can be improved as a tool to foster further innovations in the sector. To gain insights into the innovation characteristics of the ISPS qualitative expert interviews were conducted with the researchers that were responsible in setting-up, monitoring and evaluating the ISPSs.

가상경계법과 중첩격자법을 활용한 스윙 체크 밸브의 동수력학적 특성 비교

Nuclear Power Plant operators regularly check the performance of pumps and valves to verify the safety functions, and to monitor the degree of vulnerability over time through In-Service Test(IST). The swing check valve is one of the representative IST-related valve type. This valve functions to flow the fluid in only one direction, and automatically closes when the backflow occurs. In this study, the swing check valve performance test is conducted, and the result is compared with the computational fluid dynamics analysis using the immersed boundary method(ANSYS CFX R19) and overset mesh method(ANSYS Fluent R19). Overall, the inlet pressure depending on the disc angle predicted by the Fluent(overset mesh method) showed less error than the measured data compared to the CFX(immersed boundary method).The difference in the flow pattern passing through the gap between the valve entrance and top of the valve disc predicted by both methods was estimated to be the cause of the error in the simulation result compared to the measurement.

Application of On-line Digital Radiographic Inspection for Pipeline with Insulation

Pipes with insulation are widely used in the industrial field. The traditional nondestructive testing technology for on-line pipes with insulation often requires the removal of a large number of insulation layers and the forcing of the owner to stop for testing. The traditional testing mode not only has low detection efficiency, but also forces the owner to spend a lot of manpower, material resources and financial resources. In recent years, a series of new nondestructive testing (NDT) technologies have different advantages for in-service pipeline testing with coated layers. However, Digital radiographic (DR) testing can satisfy the integrity inspection of on-line pipeline with insulation well. In this paper, the basic principle of DR testing and the configuration of instrument parameters are introduced. Based on the analysis and discussion of the actual testing cases, it is proved that digital ray testing can effectively solve the quality testing of on-line insulation pipeline, and it is a new nondestructive testing technology worthy of further study and popularization.

Correlating the Asphalt-Binder MSCR Test Results to the HMA HWTT and Field Rutting Performance

Asphalt binder is one of the key constitutive components of hot-mix asphalt (HMA) that considerably affects its rutting performance. In particular, the high-temperature rheological properties measured from the multiple stress creep and recovery (MSCR) test are critical for correlating to the HMA rutting resistance. In this study, the Texas flexible pavements and overlays database was used as the data source to investigate the effect of asphalt-binder high-temperature rheological properties on the HMA rutting resistance. The study methodology was based on correlating the results of the MSCR test and the Hamburg wheel-tracking test (HWTT) to HMA field rutting performance. The data matrix for the study included asphalt binder (PG 64-22) from three different sources, three widely used Texas HMA mixes (fine gradation to coarse gradation), and five in-service highway test sections constructed using the same asphalt binders and HMA mixes. In general, the MSCR nonrecoverable creep compliance parameter, Jnrdiff, showed fairly strong correlations with the HMA rutting performance in the laboratory and field. The percent recovery parameter (R), on the other hand, exhibited the potential to ascertain and quantify the presence of modifiers in the asphalt binders. Furthermore, the test results indicated that material source/supplier has an impact on the rheological properties of the asphalt binders with the same performance grade (PG). Overall, the use of the MSCR test to quantify the asphalt-binder high-temperature rheological properties indicated the potential to compliment the laboratory HWTT test for correlating with the field HMA rutting performance in terms of the effects of asphalt binder.

ETCS (ESC) and GSM-R (RSC) compatibility tests in polish conditions

Abstract: The process of verification of the installation of the ‘on-board control-command and signalling’ subsystem is complex and requires numerous and time-consuming checks of both the overall technical documentation for a given ETCS installation on a specific vehicle, as well as checks performed during in-service tests. The experience has shown that the tests carried out in laboratories in simulated conditions and the commissioning tests of the on- board and trackside subsystems do not provide sufficient certainty in terms of the correct integration of the ‘on-board control-command and signalling’ subsystem with ‘trackside control-command and signalling’ subsystem and other subsystems. Therefore, additional tests of ETCS (European Train Control System) and GSM-R (GSM for Railways) on-board configurations with trackside ETCS and GSM-R installations on railway lines were introduced (hereinafter ESC / RSC compatibility tests). The premise of the ESC compatibility tests and RSC is to facilitate the operation of new subsystems, because their correct functioning in a given environment is fully verified at the stage of demonstrating compliance of ESC and RSC. In accordance with Polish requirements, from 1 July 2021, ESC / RSC tests are obligatory for all new, renewed and modernized projects in the field of the ‘on-board control-command and signalling’ subsystem. This obligation is a big challenge for vehicle manufacturers and users, because at that time these tests had not yet been carried out on the network managed by PKP PLK S.A. Accordingly, this article aims to introduce the issues related to the ESC and RSC tests, as well as to describe the roles and responsibilities of the various parties involved. in the implementation of the tests. Keywords: ESC / RSC tests; Compatibility; ERTMS, ETCS

International Context Regarding Application Of Single Failure Criterion (SCF) For New Reactors

The paper provides an overview of the regulatory design requirements for new reactors addressing Single Failure Criterion (SFC) in accordance to international best-practices, particularly considering the SCF relation to in-service testing, maintenance, repair, inspection and monitoring of systems, structures and components important to safety. The report [1] discusses the detailed comparison of the current SFC requirements and guidelines published by the IAEA, WENRA, EUR and nuclear regulators in the United States, United Kingdom, Russia, Korea, Japan, China and Finland. However, this paper presents the summary of work from [1] and 2major examples from IAEA and WENRA and applications for small and modular reactors.

Investigation of generative design for powder bed fusion technology in case of Formula Student race car components using Ti6Al4V alloy

In case of the racing car of the Formula Student competition, there was a need to use more modern solutions in the development of metallic parts. In the context of the joint research on the applicability of metal additive manufacturing, a methodology has been developed that will enable more efficient use of metallic parts in the future, from component selection across the generative design and 3D printing process steps to the validation of the results. As a further result of the research, we applied the new methodology to the 4 rocker components in the suspension of the racing car chassis, and as a result, we achieved a weight reduction of 40 % per component and three times higher load capacity. The built-in rocker's in-service testing and final approval took place on the ZalaZone proving ground.

Performance testing of supercoarse sintered carbides with alternative nickel-based matrices in the context of mechanical, tribological, thermal and metallographic investigations

The recent advances in rock, coal, gas and oil drilling under continuously increasing loads and increased cutting speeds motivate the interest in and development of coarse and supercoarse sintered carbides. Complex drilling conditions are best simulated during in-service tests but their objectiveness and reliability are often problematic. Therefore, performance testing of real cutting tools in controlled conditions is of great importance. New grades of supercoarse hardmetals with nickel-based binders and relevant mining tools were designed and manufactured. Performance tests consisting in controlled rotary mining of a homogeneous artificial mineral block showed significantly lower wear of the experimental sinters (24–69%) in comparison with the classical cobalt matrix counterpart. The performed mechanical, tribological, thermal, fractographic and substructural investigations revealed the wear micromechanism, the correlations between the results obtained as well as the factors of the increased tool performance.

Harmonizing Flexible Pavement Rutting Design with Balanced Mix Design

The state-of-the-practice in asphalt concrete mix design and pavement structural design are two divergent concepts. The simulative laboratory performance tests such as Hamburg Wheel Tracking (HWT) and Asphalt Pavement Analyzer (APA) that are used primarily for balanced mix design are pragmatically accelerated surrogate tests developed to ensure the stability or ranking of mixes. Pavement structural design methods, being empirical or mechanistic-empirical, do not consider these laboratory test results in their analyses, in favor of other fundamental mechanical parameters such as dynamic modulus. As such, the selection of the type of mix to be placed on a project is based on the local experience, and a set of consensus limits, rather than the demand of the pavement section. A harmonized strategy that integrates the results from mix tests with the pavement structure, material properties, environmental conditions, and traffic levels can lead to an optimized pavement system. A framework is proposed to incorporate the laboratory HWT and APA device results into the rutting analysis associated with most mechanistic-empirical structural design algorithms. The proposed framework was applied to the results from two accelerated pavement testing facilities and six in-service pavement test sections to demonstrate its feasibility. The proposed strategy can be potentially used to predict the rutting life of the pavement reasonably well. By balancing the rutting demand of an asphalt layer with the rutting capacity of a given mix, the proposed method can potentially lend itself to the use of local materials for a more economical and sustainable pavement structure.

공동 모델의 계수가 캐비테이팅 벤츄리의 내부 유동 특성에 미치는 영향에 관한 연구

Nuclear Power Plant operators regularly check the performance of pumps and valves that perform safety functions, and either monitor or evaluate the degree of vulnerability over time through In-Service Test(IST). Cavitating venturi is installed in the pipeline of the auxiliary feedwater system that is related to the IST. Cavitation is a phenomenon that impair the safety function. Accurate analysis of cavitation flow inside the cavitating venturi can contribute to improve the safety of the auxiliary feedwater system. In this study, we tried to analyze the flow characteristics inside the cavitating venturi and effect of cavitation model coefficient. The multiphase flow simulation was performed using k-ω turbulence model, Volume of Fluid(VOF) model and Zwart cavitation model, implemented in OpenFOAM and predicted results were compared with experimental data.

Study on Micro-Structure and Tensile Mechanical Properties of Dissimilar Metal Weld Joint Connecting Steam Generator Nozzle and Safe-End

The safe-end of a steam generator (SG) nozzle dissimilar metal weld (DMW) for pressurized water reactors (PWRs) is the weakest point of failure which is crucial for the safe operation of a nuclear power station. Related to materials micro-structures, a uniaxial stress–strain relationship is the basic input parameter for nuclear power plant design, safety evaluation, and life management. In this paper, the micro-structure and tensile mechanical properties of a DMW of a European pressurized water reactor (EPR) were studied. Vickers hardness tester, optical microscope, and electron back scatter diffraction were used to analyze the micro-structure of the DMW joint. In addition, the residual strain of the DMW joint base material, heat-affected zone, weld metal, and fusion boundary region were studied. Based on digital image correlation (DIC) technology, tensile mechanical properties of the DMW joint were obtained. The results show that an accurate tensile stress–strain relationship of dissimilar metal welded joints can be obtained by using the DIC technique, the weld is the relatively weak link, and the residual strain is concentrated in the heat-affected zone. This study provides valuable engineering information regarding nuclear power plant design, in-service performance testing, and structural analysis and evaluation of welds containing defects.