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Concrete-filled steel tube (CFST) structures are widely used in the construction of large-scale structures owing to its exceptional load-bearing capacity. However, inadequate construction quality and improper maintenance may cause debonding defects at the steel-concrete interface. Two non-destructive testing methods, i.e. the ultrasonic phased array (UPA) method and the impact acoustic method, are developed for deboning detection. A combined inspection procedure is proposed to balance the detection accuracy and efficiency, where the impact acoustic method is utilised for a rapid preliminary inspection to pinpoint the suspected debonding areas, while the UPA method is sequentially applied to accurately evaluate the debonding rates in the suspected areas. The impact acoustic method analyzes the time-frequency spectrum from the echo signals using wavelet transform, and calculates the vibration energy ratio for debonding detection. The UPA method applies the total focusing method for image reconstruction, and extracts the reflection coefficient at the steel–concrete interface for debonding evaluation. The laboratory experimental results show that the combined method possesses a high accuracy and accurately delineates the range of the debonding defect while preserving the detection efficiency. Field tests conducted on an arch bridge in Foshan, China, verified the effectiveness of the proposed evaluation method. [ABSTRACT FROM AUTHOR]

With the continuous progress of technology, computed tomography (CT) technology has expanded from medicine to agriculture and other industries. With the advantages of non-destructiveness, high resolution, and high precision, CT technology shows great application potential in the agricultural field. However, there are still some problems with this technology that need to be solved. This paper aims to show the application of CT technology in the agricultural field, find technical challenges, and put forward specific countermeasures, so that CT technology can be better applied in the agricultural field. This paper summarizes the application of CT technology in the quality detection of agricultural products, disease and insect pest identification, seed screening, soil analysis, and precision agriculture management, and focuses on the current challenges and the countermeasures, and looks into the role of this technology in promoting agricultural development in the future. Despite various challenges, CT technology has far more advantages than disadvantages, and it is expected to become an indispensable part of all the links of agricultural production and promote the development of precision agriculture and smart agriculture. [ABSTRACT FROM AUTHOR]

A deployable reflector antenna (DR-A) is a structure that can be stored in a large-diameter Synthetic Aperture Radar (SAR) antenna and be mounted onto a launch vehicle. Considering the performance of the launch vehicle, it is necessary to develop a lightweight, high-performance antenna structure. The solid-type deployable reflector antenna is composed of a number of unit main reflectors. To reduce the weight of the antenna, a lightweight main reflector must be developed. In this paper, following "Development of Deployable Reflector Antenna for the SAR Satellite (Part 1)", the manufacturing and qualification of the main reflector using honeycomb sandwich composites are described. Four types of composite main reflectors were manufactured with variables in the manufacturing process. The manufacturing variables include the curing process of the structure, the application of an adhesive film between the sheet and the core, and the venting path inside of the sandwich core. After manufacturing the main reflector, we performed weight measurements, non-destructive testing (NDT), surface error measurement using a Coordinate Measurement Machine (CMM), and modal testing for each type of composite main reflector. Through the research and development process, we found that a perforated hole is necessary when excluding the adhesive film during bonding of an aramid core and a CFRP sheet, and a lightweight composite reflector could be developed through this process. We selected the main reflector with the best performance and developed a composite main reflector that can be applied to satellites. [ABSTRACT FROM AUTHOR]

This review examines the integration of advanced ultrasonic techniques and artificial intelligence (AI) for monitoring and analyzing concrete structures, focusing on detecting and classifying internal defects. Concrete structures are subject to damage over time due to environmental factors and dynamic loads, compromising their integrity. Non-destructive techniques, such as ultrasonics, allow for identifying discontinuities and microcracks without altering structural functionality. This review addresses key scientific challenges, such as the complexity of managing the large volumes of data generated by high-resolution inspections and the importance of non-linear models, such as the Hammerstein model, for interpreting ultrasonic signals. Integrating AI with advanced analytical models enhances early defect diagnosis and enables the creation of detailed maps of internal discontinuities. Results reported in the literature show significant improvements in diagnostic sensitivity (up to 30% compared to traditional linear techniques), accuracy in defect localization (improvements of 25%), and reductions in predictive maintenance costs by 20–40%, thanks to advanced systems based on convolutional neural networks and fuzzy logic. These innovative approaches contribute to the sustainability and safety of infrastructure, with significant implications for monitoring and maintaining the built environment. The scientific significance of this review lies in offering a systematic overview of emerging technologies and their application to concrete structures, providing tools to address challenges related to infrastructure degradation and contributing to advancements in composite sciences. [ABSTRACT FROM AUTHOR]

Concrete is one of the most important elements in building construction. However, concrete used in construction is susceptible to damage due to corrosion. The influence of corrosive substances causes changes in the reinforcing steel and affects the strength of the structure. The repair method is one approach to overcome this problem. This research aims to determine the effect of grouting and jacketing repairs on corroded concrete. The concrete used has dimensions of 15 cm × 15 cm × 60 cm with planned corrosion variations of 50%, 60%, and 70%. The test objects were tested using the Non-Destructive Testing (NDT) method using Ultrasonic Pulse Velocity (UPV). The test results show that the average speed of normal concrete is 5070 m/s, while the lowest average speed is 3070 m/s on the 70% planned corrosion test object. The test object was then given a load of 1600 kgf. At this stage, there is a decrease in speed and wave shape with the lowest average speed obtained at 2753 m/s. The repair method is an effort to restore concrete performance by using grouting and jacketing. Grouting is done by injecting mortar material into it. Jacketing involves adding thickness to the existing concrete layer with additional layers of concrete. After improvements were made, there was an improvement in the UPV test, with a peak speed value of 4910 m/s. Repairing concrete by filling cracks can improve concrete continuity and reduce waveform distortion, thereby increasing wave propagation speed. [ABSTRACT FROM AUTHOR]

In this paper, the effect of radiation hazards on the environment while using the non-destructive radiography method was investigated. The research was carried out by measuring the radiation amounts at 0.5 and 2 m distance from the exposure container with radioactive iridium-192 isotope used for tests with the radiography method. The tests were carried out in different positions in relation to the protective bunkers used in the company STSI Ltd. (Zagreb, Croatia) to reduce the radiation emission of the used radioactive isotope. The effectiveness of the protective bunkers in terms of reducing radiation in the environment is determined. In addition to examining the effects and hazards of radiation, the procedure for proper disposal of hazardous and non-hazardous waste generated by the non-destructive radiography method is described. Research has shown that the storage of exposure containers with radioactive iridium-192 isotope in the large protective bunker and the mini-bunker contributes to the improvement of environmental and personnel protection. The disposal of hazardous and non-hazardous waste after testing with the non-destructive radiography method has also proven to be of enormous importance for environmental protection.

There is a need for non‐destructive testing (NDT) methods to evaluate concrete properties in fresh and hardened states. The current study aims to utilize the piezoelectric ring actuator technique (P‐RAT), originally developed for soil applications, to assess the properties of cementitious materials. The research presents the adaptation of P‐RAT to monitor hydration kinetics of cement‐based materials at an early age. The technique measures shear wave velocity (VS) through the materials, offering insights into their behavior during the setting process. The methodology involves a new configuration for the sample holder and new ring dimensions adapted to obtain resonance frequency appropriate for evaluating the cementitious materials at an early age. The study includes an experimental evaluation of different cement paste and mortar mixtures—focusing on examining factors like repeatability, calibration, and ability to determine setting times using both P‐RAT in comparison to traditional methods like the Vicat needle test. The study demonstrates the feasibility of adapting the P‐RAT technique to measure VS along with its potential to provide valuable insights into the cement‐based materials' characteristics during their critical early stages of development. [ABSTRACT FROM AUTHOR]

Ultrasonic thermal excitation can be regulated by coupling pressure conditions that indirectly influence the excitation effect. This study evaluated the effects of coupling pressure conditions on concrete microcracks detection through ultrasonic thermal excitation testing. Concrete microcracks were subjected to coupling tests, and two coupling pressure conditions were applied to the stimulation. A finite element simulation model was used to quantify the coupling pressure excitation, and the differences in temperature rises due to the coupling pressure conditions were analyzed. The study indicates the addition fluctuations in coupling pressure under the direct loading excitation could be neglected; while the coupling pressure increases by about 53% under the aluminum alloy sleeve loading excitation, and the fluctuation increases with the initial coupling pressure. The excitation effects of the tests are influenced by the coupling pressure condition, which will be weak if the perturbation of coupling pressure is great and changes drastically. Analysis suggests the drastically varying coupling pressure leads to substantial changes in the transducer's equivalent resistance and the output efficiency of the piezoelectric transducer decreases. It emphasizes the importance of controlling the perturbation of coupling pressure and provides research ideas to enhance the detection efficiency. [ABSTRACT FROM AUTHOR]

Non-destructive inspection and analysis techniques are crucial for quality assessment and defect analysis in various industries. They enable for screening and monitoring of parts and products without alteration or impact, facilitating the exploration of material interactions and defect formation. With increasing complexity in microelectronic technologies, high reliability, robustness and thus, successful failure analysis is essential. Machine learning (ML) approaches have been developed and evaluated for the analysis of acoustic echo signals and time-resolved thermal responses for assessing their ability for defect detection. In the present paper different ML architectures were evaluated, including 1D and 2D convolutional neural networks (CNNs) after transforming time domain data into the spectral- and wavelet domains. Results showed that 2D CNNs processing data in wavelet domain representation performed best, however at the expense of additional computational effort. Furthermore, ML-based analysis was explored for lock-in thermography to detect and locate defects in the axial dimension based on thermal emissions. While promising, further research is needed to fully realize its potential. [ABSTRACT FROM AUTHOR]

This paper investigates the capabilities of the resonant cavity system (ResCav) for detecting tampered integrated circuits (ICs) within supply chains. Prior research showcased ResCav's ability to discern minor circuit variations, this study focuses on enhancing supervised classification results and introduces a one-class support vector machine (SVM) approach with a modified radial basis function kernel for novelty detection. Through finer hyperparameter tuning, the system achieves improved classification accuracy, demonstrating its potential to identify nuanced alterations with even higher precision and recall rates. Additionally, the application of a one-class SVM enables the detection of tampered ICs without reliance on labeled datasets, expanding utility in scenarios where access is limited to golden ICs. These advancements in ResCav's capabilities signify progress in failure prevention methodologies, offering an efficient and non-destructive solution crucial for safeguarding against counterfeit and non-conforming components infiltrating critical supply chains. [ABSTRACT FROM AUTHOR]

In this paper, the effect of radiation hazards on the environment while using the non-destructive radiography method was investigated. The research was carried out by measuring the radiation amounts at 0.5 and 2 m distance from the exposure container with radioactive iridium-192 isotope used for tests with the radiography method. The tests were carried out in different positions in relation to the protective bunkers used in the company STSI Ltd. (Zagreb, Croatia) to reduce the radiation emission of the used radioactive isotope. The effectiveness of the protective bunkers in terms of reducing radiation in the environment is determined. In addition to examining the effects and hazards of radiation, the procedure for proper disposal of hazardous and non-hazardous waste generated by the non-destructive radiography method is described. Research has shown that the storage of exposure containers with radioactive iridium-192 isotope in the large protective bunker and the mini-bunker contributes to the improvement of environmental and personnel protection. The disposal of hazardous and non-hazardous waste after testing with the non-destructive radiography method has also proven to be of enormous importance for environmental protection. [ABSTRACT FROM AUTHOR]

In this paper, an iterative numerical approximation technique is used for analyzing the distribution of eddy currents density in conductive materials plates by using the electromagnetic T-formulation and the Biot-Savart law, solved by the finite element method. The proposed approach allows for the meshing of the different parts of the studied system separately, including the sensor and the conductive plate, without the need for an air region. Firstly, this approach reduces the number of unknown variables by avoiding the air region of the system's mesh. Secondly, it simplifies the consideration of the sensor's motion without the need to remesh the system. For this purpose, a calculation code has been developed for solving an electromagnetic three-dimensional non-destructive testing model. This latter permits the resolution of JSEAM # 6 Benchmark problem to validate the proposed method. The impedance variation due to the presence of a defect are evaluated. The obtained results are compared with the experimental ones found in the literature. These results reveal a good agreement, which proves the validity of the proposed method. [ABSTRACT FROM AUTHOR]

Non-contact infrared thermography measurement has exhibited advantages of cost saving, fast inspection time, and high efficiency. However, infrared thermography has a relatively low spatial resolution which leads to low quality thermal images. This paper suggests a new wavelet-based technique by merging of new edge-directed interpolation (NEDI) with wavelet zero padding (WZP), and discrete wavelet transform (DWT). The developed technique is built upon the target of improving the visual effect of blurring thermal images with increasing spatial resolution, thus producing high quality thermal images. The DWT procedure is applied through dividing the low-resolution image to four frequencies of sub-bands. For a good reconstruction of a high-resolution image, the sub-band of low-frequency is estimated by applying WZP to the perceived image. The rest three sub-bands of high-frequencies are handled by NEDI and a soft threshold-method so as to maintain more edges and remove probable noise. The accomplishment of the suggested approach has been examined on diverse types of thermal images. The experimental results appear the distinction of the suggested technique above the interpolation and state-of-the-art wavelet-based techniques. [ABSTRACT FROM AUTHOR]

Non-destructive testing (NDT) techniques play a crucial role in industrial production, aerospace, healthcare, and the inspection of special equipment, serving as an indispensable part of assessing the safety condition of pressure equipment. Among these, the analysis of NDT data stands as a critical link in evaluating equipment safety. In recent years, object detection techniques have gradually been applied to the analysis of NDT data in pressure equipment inspection, yielding significant results. This paper comprehensively reviews the current applications and development trends of object detection algorithms in NDT technology for pressure-bearing equipment, focusing on algorithm selection, data augmentation, and intelligent defect recognition based on object detection algorithms. Additionally, it explores open research challenges of integrating GAN-based data augmentation and unsupervised learning to further enhance the intelligent application and performance of object detection technology in NDT for pressure-bearing equipment while discussing techniques and methods to improve the interpretability of deep learning models. Finally, by summarizing current research and offering insights for future directions, this paper aims to provide researchers and engineers with a comprehensive perspective to advance the application and development of object detection technology in NDT for pressure-bearing equipment. [ABSTRACT FROM AUTHOR]

The inspection of thick-section sandwich structures with skins around core materials such as honeycomb, balsa, and foam relies on low-frequency vibration techniques to identify defects through changes in amplitude or phase response. However, current industrial methods are often limited to detecting specific types of defects, potentially overlooking others. Moreover, these methods do not gather detailed information about the defect type or depth, as they only analyse a small portion of the available data instead of the full relevant response spectrum. This paper explores the scientific basis of using low-frequency vibration in the pitch-catch variant for defect detection in homogeneous solids, through analysis of the full relevant frequency spectrum (5–50 kHz). Defects in structures lead to reduced local stiffness and mass in the affected area, causing resonance in the layer above, resulting in amplified vibrations known as local defect resonance (LDR). In this work, an aluminium plate with a 40 mm diameter circular flat-bottomed hole (FBH) at a depth of 1 mm (representing a skin defect) is excited with a chirp signal of 5–50 kHz, and the response is monitored 17 mm away from the excitation point. Finite-element analysis (FEA) is used for the numerical model, addressing challenges in creating an accurate model. The process to optimise the numerical model and the reduce model-experiment error is outlined, including challenges such as the lack of knowledge of material damping. The study emphasizes the importance of modelling the probe’s stiffness and damping effects for achieving agreement between the model and experiment. After incorporating these effects, the maximum LDR frequency error decreased from approximately 3 kHz to less than 1 kHz. In addition, this study presents a method with the potential for defect classification through comparison to modelled responses. The minimum difference error was used to quantify the resonance frequencies’ error between the model and the experiment. Since the resonant frequencies are a function of the defect’s shape, size, and depth, a relatively low root mean squared (RMS) error across the resonance frequency error spectrum indicates the defect’s characteristics. Finally, defect detection and sizing using the pitch-catch probe are explored with a wide-band excitation signal and a line scan through the mid-plane of the defect. A method for defect sizing using a pitch-catch probe is presented and experimentally validated. Accurate defect sizing is achieved with the pitch-catch probe when the defect width is at least ≥ twice the 17 mm pin-spacing of the probe. [ABSTRACT FROM AUTHOR]

Railways serve as a vital link for global trade and transportation in any country, but the rail sections are susceptible to damage due to factors such as traffic, extreme environment, and other unavoidable conditions. Monitoring such damages in real time is crucial to prevent casualties and economic losses. Non-destructive testing (NDT) techniques have been used for damage localization, and the acoustic emission (AE) technique has gained attention for real-time monitoring. However, conventional AE approaches are complex, time-consuming, and require multiple sensors. An alternative method is needed for easy and effective implementation of damage localization in rail sections using AE signals. In this study presents, a deep learning approach deploying Artificial Neural Network (ANN) and Support Vector Machine (SVM) models under AI is illustrated experimentally for easy and effective implementation of the damage localization process in the rail section. The novelty in this approach is the application of single AE sensor data which makes the damage localization process economical and less time-consuming. These findings have significant implications for the scientific community and rail transportation industries, ensuring safe and efficient operations.. [ABSTRACT FROM AUTHOR]

This review paper aims to understand the current processing plant maintenance systems and further identify on-stream phased array corrosion mapping (PACM) to reduce turnaround maintenance (TAM) activity during plant operations. Reducing the TAM duration and extending the TAM interval are common goals of most researchers. Thus, a detailed review was performed to understand the maintenance systems and the problems faced. Furthermore, a review of the current PACM application and the possibility of applying it during on-stream inspection was also performed. PACM has better detectability for localized corrosion, and the results can be obtained for a range of thicknesses, which is the main advantage of this method. However, applying PACM during on-stream inspections at elevated temperatures presents challenges owing to the limitations of the ultrasonic properties and increased probe contact. Future research is needed to evaluate the effectiveness of PACM on piping systems that can be utilized for inspection during plant operation at elevated temperatures. This will enable the detection of general and localized corrosion in common materials, thereby reducing the TAM duration and extending TAM intervals. Detecting and monitoring corrosion growth without shutdown is critical for ensuring the safety and reliability of the processing plants. This literature review provides a more precise direction for future research to address these challenges and to advance the field of on-stream corrosion monitoring. [ABSTRACT FROM AUTHOR]

This study aims to develop a damage-detection algorithm based on the electromagnetic wave properties inside a reinforced concrete structure. The proposed method involves employing two algorithms based on data measured using ground-penetrating radar—a common electromagnetic wave method in civil engineering. The possible defect area was identified based on the energy dissipated by the damage in the frequency-wavenumber domain, with the damage localized using the calculated relative permittivity of the measurements. The proposed method was verified through a finite difference time-domain-based numerical analysis and a testing slab with artificial damage. As a result of verification, the proposed method quickly identified the presence of damage inside the concrete, especially for honeycomb-like defects located at the top of the rebar. This study has practical significance in scanning structures over a large area more quickly than other non-destructive testing methods, such as ultrasonic methods. [ABSTRACT FROM AUTHOR]

This review aims to study the process plant damage mechanisms published by previous research, such as general corrosion, localised corrosion, and stress corrosion cracking. This review was conducted by analysing the current application of the common inspection method and technique and focusing on the phased array ultrasonic testing application. In order to further the current study, the review seeks direction on evaluating phased array corrosion mapping techniques to detect corrosion and metal loss during plant operation and minimise the plant’s need for maintenance. This systematic literature review provides a better understanding of the current damage mechanisms and shows the possibility of an extended future study. [ABSTRACT FROM AUTHOR]

This paper discusses the complexities of non-destructive testing (NDT) for solid propellants in rocket motors, emphasising on the significance and evolution of various inspection techniques. It addresses the challenges associated with different propellant types and the inherent difficulties in defect detection. By highlighting recent advancements in digital methodologies and automated defect recognition (ADR), the study underscores the critical role of NDT in ensuring the safety and effectiveness of rocket motors, and points towards future technological trends and research needs. Given the crucial role of solid rocket motors in aerospace and defence, their inspection is paramount. Traditional methods, such as visual inspection (VI), have been essential for identifying surface defects such as cracks and debonding, though they are limited to surface anomalies. Advancements in radiographic testing, including conventional and digital radiography, have improved the detection of internal flaws such as voids, porosity, foreign objects or inclusions, and cracks. Digital radiography, utilising computed radiography (CR) and digital detector arrays (DDA), provides superior resolution and faster imaging, making it invaluable for detailed inspections. Ultrasonic testing (UT) has been instrumental, with pulse echo and through-transmission methods offering insights into internal discontinuities and bonding integrity. UT methods, particularly through-transmission, avoid contamination from couplants and are suitable for automated scanning. Shearography, using laser light to detect surface and subsurface defects, offers real-time feedback and quantitative analysis, particularly for detecting debonding and improper adhesion. Industrial computed tomography (ICT) provides high-resolution three-dimensional imaging, crucial for identifying structural abnormalities and ensuring propellant integrity, although it is challenged by high costs and operational complexity. Laser scanning thermography (LasST) generates detailed thermal maps to identify defects and material inconsistencies, making it suitable for in-line inspections during manufacturing. Recent advancements in NDT include integrating artificial intelligence (AI) and machine learning (ML) for ADR, enhancing defect detection, reducing human error, and supporting predictive maintenance. However, these technologies face challenges such as high costs, the need for specialised skills and the complexity of integration with existing methods. The future of NDT for solid propellants lies in developing cost-effective methods, standardised procedures, and portable equipment for on-site inspections. Embracing AI and ML will further automate and improve defect analysis, ensuring higher safety and performance standards for solid rocket motors. [ABSTRACT FROM AUTHOR]

Non-Destructive Testing (NDT) methods play a pivotal role in ensuring the safety and reliability of aircraft in the aviation industry. This article provides a comprehensive overview of the NDT techniques commonly employed in aviation to assess the structural integrity and performance of aircraft components and materials without causing any damage. The article discusses the significance of NDT in aviation, highlighting the importance of early defect detection, maintenance cost reduction, and enhanced operational safety. It delves into various NDT methods, such as ultrasonic testing, eddy current testing, radiographic inspection, magnetic particle testing, and dye penetrant testing, explaining their principles and applications. In addition, in this article, the advantages and disadvantages of NDT methods and which methods are used in which part of the aircraft are mentioned. Understanding these NDT methods is crucial for aviation professionals, as they contribute to the continued airworthiness of aircraft, ensuring that passengers and crew can travel safely and confidently. [ABSTRACT FROM AUTHOR]

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With the continuous progress of technology, computed tomography (CT) technology has expanded from medicine to agriculture and other industries. With the advantages of non-destructiveness, high resolution, and high precision, CT technology shows great application potential in the agricultural field. However, there are still some problems with this technology that need to be solved. This paper aims to show the application of CT technology in the agricultural field, find technical challenges, and put forward specific countermeasures, so that CT technology can be better applied in the agricultural field. This paper summarizes the application of CT technology in the quality detection of agricultural products, disease and insect pest identification, seed screening, soil analysis, and precision agriculture management, and focuses on the current challenges and the countermeasures, and looks into the role of this technology in promoting agricultural development in the future. Despite various challenges, CT technology has far more advantages than disadvantages, and it is expected to become an indispensable part of all the links of agricultural production and promote the development of precision agriculture and smart agriculture.

A deployable reflector antenna (DR-A) is a structure that can be stored in a large-diameter Synthetic Aperture Radar (SAR) antenna and be mounted onto a launch vehicle. Considering the performance of the launch vehicle, it is necessary to develop a lightweight, high-performance antenna structure. The solid-type deployable reflector antenna is composed of a number of unit main reflectors. To reduce the weight of the antenna, a lightweight main reflector must be developed. In this paper, following “Development of Deployable Reflector Antenna for the SAR Satellite (Part 1)”, the manufacturing and qualification of the main reflector using honeycomb sandwich composites are described. Four types of composite main reflectors were manufactured with variables in the manufacturing process. The manufacturing variables include the curing process of the structure, the application of an adhesive film between the sheet and the core, and the venting path inside of the sandwich core. After manufacturing the main reflector, we performed weight measurements, non-destructive testing (NDT), surface error measurement using a Coordinate Measurement Machine (CMM), and modal testing for each type of composite main reflector. Through the research and development process, we found that a perforated hole is necessary when excluding the adhesive film during bonding of an aramid core and a CFRP sheet, and a lightweight composite reflector could be developed through this process. We selected the main reflector with the best performance and developed a composite main reflector that can be applied to satellites.

Quantitative imaging technologies for in-situ non-destructive testing (NDT) demand high-resolution, wide-field, and stable metrology capabilities. Moreover, live processing and automation are vital for real-time quality control and inspection. Conventional methods use complex optical setups, resulting in large, immobile systems which can solely operate within controlled environmental conditions due to temporal instabilities, rendering them unsuitable for in-situ measurements of micro-to nano-scale physical phenomena. This article delves into the multiphysics application of lensless digital holography, emphasizing its metrological capacity for various in-situ scenarios, while acknowledging and characterizing the differing constraints imposed by various physical phenomena, both transient and steady-state. The digital reconstruction of holograms is computed in real-time, and numerical focusing capabilities allow for instantaneous retrieval of the optical phase at various working distances without the need of complex optical setups, making lensless digital holography well-suited for in-situ quantitative imaging under various types of environments. Current NDT capabilities are demonstrated, including high-resolution and real-time reconstructions, simultaneous measurements for comparative metrology, and practical applications ranging from vibrations and acoustics to thermo-mechanics. Furthermore, methodologies to enhance overall metrology capabilities are exploited, addressing the study of existing physical phenomena, thereby expanding the applicability of holographic techniques across diverse industrial sectors. [ABSTRACT FROM AUTHOR]

Using glass as a structural element that could obtain the role of the primary load-bearing elements of iconoclast structures has had a superficial history. Because of its aesthetic and admissible mechanical properties, glass has been considered one of the structural elements in the construction industry. Because of its extrasafety, laminated glass on top of the most widely used elements has been appraised with more depth. The study aimed to evaluate the failure modes in laminated glass and the possibility of detecting the pre-failure status of the surveyed elements, referring to the proffered approaches and image processing (IP) procedures in the literature. The outcomes have compared the peculiarity and strength points of various routes and have reached the inference for proper approaches in every procedure. According to the results, image processing (IP) is the most appropriate method of pre-failure detection in load-bearing laminated glass elements. Among the image processing (IP) techniques, digital image correlation has the widest application. The results of this study, in combination with other pieces of research, may propound a database for evaluating the failure status of glass structures. [ABSTRACT FROM AUTHOR]

This paper deals with the description and use of one of the up-to-date NDT method, the ultrasonic pulse echo, to determine the thickness of an asphalt concrete model. In the article, the authors explain the principle of the method and the limits of its use. Furthermore, attention is also paid to the influence of the shape and design of the back wall of the tested elements and the speed of propagation of ultrasonic waves. The research is part of a larger work, defect analysis and implementation of Whitetopping technology in the Czech Republic. [ABSTRACT FROM AUTHOR]

The probability of defects detection (POD) is developed as an efficient tool to evaluate the detection capacity of non-destructive testing methods. An experimental study has been carried out applying the magnetic particle test method with an electromagnetic yoke on welded steel joints, which contained surface defects previously characterized in shape, size and location. The test conditions were varied, such as the type of magnetization current, and the type of magnetic particle. The probability of detecting defects in welded joints evaluated by the Hit/miss method increased with the size of the defect, independent of its shape factor. Smaller defects were likely to be detected with dry magnetic particles compared to wet fluorescent ones, a50 (2,118 mm < 2,469 mm), a90 (6,395 mm < 6,77 mm) and α90/95 (12,12 mm < 12,19 mm). [ABSTRACT FROM AUTHOR]

Ice accumulation on infrastructure poses severe safety risks and economic losses, necessitating effective detection and monitoring solutions. This study introduces a novel approach employing surface acoustic wave (SAW) sensors, known for their small size, wireless operation, energy self-sufficiency, and retrofit capability. Utilizing a SAW dual-mode delay line device on a 64°-rotated Y-cut lithium niobate substrate, we demonstrate a solution for combined ice detection and temperature measurement. In addition to the shear-horizontal polarized leaky SAW, our findings reveal an electrically excitable Rayleigh-type wave in the X+90° direction on the same cut. Experimental results in a temperature chamber confirm capability for reliable differentiation between liquid water and ice loading and simultaneous temperature measurements. This research presents a promising advancement in addressing safety concerns and economic losses associated with ice accretion. [ABSTRACT FROM AUTHOR]

In this work, we present a system architecture that is especially designed for remote ultrasound testing inspections (UT). The system itself is realized using a real-time session service and a web service based on a REST API (REST: Representational State Transfer; API: application programming interface). This web service is used to store data persistently, e.g., sample geometries, raw nondestructive testing (NDT) data and derived inspection results in a shared dataspace. In the current development state, the results consist of textures mapped onto the sample geometry. This approach allows us to display the UT results directly on the real sample using mixed reality technologies. We also implemented a feature to assist the inspector remotely by making use of the availability of this digital representation. Hence, it is necessary to share additional data like the current UT-signal, temporary position marks, user and device positions, etc. between the different participants. A real-time distribution of this highly dynamic data is required to create an effective assistance environment. Therefore, a separate session service is used. The inspection data generated in this temporary session can also be transferred to the afore mentioned dataspace to be saved persistently. The system features mixed reality visualization for the inspector and optionally a virtual reality or a 3D Desktop environment for one or more remote assistants. [ABSTRACT FROM AUTHOR]

Fiber-Reinforced Polymer (FRP) composites have emerged as a promising alternative to conventional steel reinforcements in concrete structures owing to their benefits of corrosion resistance, higher strength-to-weight ratio, reduced maintenance cost, extended service life, and superior durability. However, there has been limited research on non-destructive testing (NDT) methods applicable for identifying damage in FRP-reinforced concrete (FRP-RC) elements. This knowledge gap has often limited its application in the construction industry. Engineers and owners often lack confidence in utilizing this relatively new construction material due to the challenge of assessing its condition. Thus, the main objective of this study is to determine the applicability of two of the most common NDT methods: the Ground-Penetrating Radar (GPR) and Phased Array Ultrasonic (PAU) methods for the detection of damage in FRP-RC elements. Three slab specimens with variations in FRP type (glass-, carbon- and basalt-FRP, i.e., GFRP, CFRP, and BFRP, respectively), bar diameter, bar depths, and defect types were investigated to determine the limitations and detection capabilities of these two NDT methods. The results show that GPR could detect damage in GFRP bars and CFRP strands, but PAU was limited to damage detection in CFRP strands. The findings of this study show the applicability of conventional NDT methods to FRP-RC and at the same time identify the areas with a need for further research. [ABSTRACT FROM AUTHOR]

Laser-based powder bed fusion of metals (PBF-LB/M) is a widely applied additive manufacturing technique. Thus, PBF-LB/M represents a potential candidate for the processing of quenched and tempered (Q&T) steels such as 42CrMo4 (AISI 4140), as these steels are often considered as the material of choice for complex components, e.g., in the toolmaking industry. However, due to the presence of process-induced defects, achieving a high quality of the resulting parts remains challenging in PBF-LB/M. Therefore, an extensive quality inspection, e.g., using process monitoring systems or downstream by destructive or non-destructive testing (NDT) methods, is essential. Since conventionally used downstream methods, e.g., X-ray computed tomography, are time-consuming and cost-intensive, micromagnetic NDT measurements represent an alternative for ferromagnetic materials such as 42CrMo4. In this context, 42CrMo4 samples were manufactured by PBF-LB/M with different process parameters and analyzed using a widely established micromagnetic measurement system in order to investigate potential relations between micromagnetic properties and porosity. Using multiple regression modeling, relations between the PBF-LB/M process parameters and six selected micromagnetic variables and relations between the process parameters and the porosity were assessed. The results presented reveal first insights into the use of micromagnetic NDT measurements for porosity assessment and process parameter optimization in PBF-LB/M-processed components. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach for preload measurement of bolted connections, specifically tailored for offshore wind applications. The proposed method combines robotics, Phased Array Ultrasonic Testing (PAUT), nonlinear acoustoelasticity, and Finite Element Analysis (FEA). Acceptable defects, below a pre-defined size, are shown to have an impact on preload measurement, and therefore conducting simultaneous defect detection and preload measurement is discussed in this paper. The study demonstrates that even slight changes in the orientation of the ultrasonic transducer, the non-automated approach, can introduce a significant error of up to 140 MPa in bolt stress measurement and therefore a robotic approach is employed to achieve consistent and accurate measurements. Additionally, the study emphasises the significance of considering average preload for comparison with ultrasonic data, which is achieved through FEA simulations. The advantages of the proposed robotic PAUT method over single-element approaches are discussed, including the incorporation of nonlinearity, simultaneous defect detection and stress measurement, hardware and software adaptability, and notably, a substantial improvement in measurement accuracy. Based on the findings, the paper strongly recommends the adoption of the robotic PAUT approach for preload measurement, whilst acknowledging the required investment in hardware, software, and skilled personnel. [ABSTRACT FROM AUTHOR]

This paper presents a set of Ground Penetrating Radar (GPR) data obtained from in situ measurements conducted in four ornamental stone quarries located in Italy (Botticino quarry) and Romania (Ruschita, Carpinis, and Pietroasa quarries). The GPR is a Non-Destructive Testing (NDT) technique that enables the detection and localization of fractures without damage to the surface, among other capabilities. In this study, two instruments of ground-coupled GPR were used to detect and locate the fractures, discontinuities, or weakened zones. The GPR data contains radargrams for discontinuities and fracture detection, besides the geographic location of the measures. For each measurement site, a set of radargrams has been acquired in two orthogonal directions, allowing for a 3D reconstruction of the investigated site. Dataset: DOI:10.17632/w26n6nftxs.3 (https://data.mendeley.com/datasets/w26n6nftxs/3) Dataset License: CC BY-NC-ND [ABSTRACT FROM AUTHOR]

Offshore oil and gas resources play a crucial role in supplementing the energy needs of human society. The crisscrossing subsea pipeline network, which serves as vital infrastructure for the storage and transportation of offshore oil and gas, requires regular inspection and maintenance to ensure safe operation and prevent ecological pollution. In-line inspection (ILI) techniques have been widely used in the detection and inspection of potential hazards within the pipeline network. This paper offers an overview of ILI techniques used in subsea pipelines, examining their advantages, limitations, applicable scenarios, and performance. It aims to provide valuable insights for the selection of ILI technologies in engineering and may be beneficial for those involved in pipeline integrity management and planning. [ABSTRACT FROM AUTHOR]

This study presents a non-destructive testing (NDT) thermographic procedure for assessing the quality and mechanical strength of Resistance Projection Welded (RPW) joints with rectangular embossments. We analysed twelve RPW joints by systematically varying process parameters based on a factorial design. These joints underwent flash thermography followed by mechanical tests to evaluate the maximum breaking force (Fmax). Significant statistical correlations between process parameters (time and force) and Fmax were established. Furthermore, we found a correlation (p-value 0.86) between the optically measured fused region and Fmax. Subsequently, we developed a pulsed phase thermography-based procedure for non-destructively measuring the fused region, resulting in an average difference of approximately 4 % compared to optical measurements. An empirical linear relationship was derived to correlate the welded area obtained by thermal data with Fmax, enabling the estimation of mechanical joint strength through non-destructive pulsed thermography. This research offers a promising approach for assessing the mechanical integrity of RPW joints using thermal imaging techniques.

Quantitative imaging technologies for in-situ non-destructive testing (NDT) demand high-resolution, wide-field, and stable metrology capabilities. Moreover, live processing and automation are vital for real-time quality control and inspection. Conventional methods use complex optical setups, resulting in large, immobile systems which can solely operate within controlled environmental conditions due to temporal instabilities, rendering them unsuitable for in-situ measurements of micro-to nano-scale physical phenomena. This article delves into the multiphysics application of lensless digital holography, emphasizing its metrological capacity for various in-situ scenarios, while acknowledging and characterizing the differing constraints imposed by various physical phenomena, both transient and steady-state. The digital reconstruction of holograms is computed in real-time, and numerical focusing capabilities allow for instantaneous retrieval of the optical phase at various working distances without the need of complex optical setups, making lensless digital holography well-suited for in-situ quantitative imaging under various types of environments. Current NDT capabilities are demonstrated, including high-resolution and real-time reconstructions, simultaneous measurements for comparative metrology, and practical applications ranging from vibrations and acoustics to thermo-mechanics. Furthermore, methodologies to enhance overall metrology capabilities are exploited, addressing the study of existing physical phenomena, thereby expanding the applicability of holographic techniques across diverse industrial sectors.

This paper reports an investigation of the mechanical and microscopic properties of partially replaced banana leaf ash (BLA) concrete. In this research, the cement was partially replaced by BLA in two phases: Phase A (0%, 5%, 10%, 15%, 20%, 25% and 30%) and Phase B (0%, 10%, 20% and 30%). The consequence of partially replacing cement with BLA in concrete was investigated by the application of a range of tests, namely X-ray fluorescence (XRF), compressive strength, splitting tensile strength, flexure strength, ultrasonic pulse velocity and scanning electron microscopy (SEM) analysis. The properties were then correlated with the properties of a standard 100% Portland cement concrete of similar strength. The XRF result of the BLA identified a composition with 48.93% SiO2 and 3.48% Al2O3, which indicates that the material potentially possesses pozzolanic properties. The mechanical properties of the partially replaced BLA concrete noted minor strength loss, approximately 5% with 20% partial replacement. The nondestructive testing data showed enhanced performance up to 20% partial replacement, with ultrasonic pulse values above 3500 m/s. The scanning electron microscopy analysis illustrated that the morphology of BLA specimens contained increased microcracks compared with the control. The decrease in strength observed is attributed to the fibrous composition of the BLA. The mechanical, nondestructive testing and microscopic results highlight the potential to utilize BLA as a partial replacement for cement as a pozzolanic material in concrete at up to 20% by weight of cement. [ABSTRACT FROM AUTHOR]