Industry 4.0 in maintenance: Using condition monitoring in electric machines

Industry traditionally considered maintenance as a cost and a necessity to replace equipment and machines, but the path has changed to better focus on maintenance to prevent faults and it was designated as predictive. The ones motivated to take these advantages are faced with two of the biggest barriers: the investment it requires and the difficulty to develop algorithms. The costs of installation are still high, but the avoided costs surpass it. Also, Internet of Things (IoT) has brought a big shift, which is been known as the industry 4.0. One of the potentials in maintenance is the conditioning monitoring. Condition monitoring sensors and devices are now linked to maintenance platforms, providing real-time data. This new connectivity is both more affordable and easier to implement than predictive maintenance. Real-time data allows managers to adjust preventive maintenance plans while providing greater reliability. At the same time, artificial intelligence manages this data to recognize patterns, which is one of the most promising advances in digital reliability. So, regardless of the ability to immediately implement a preventive maintenance plan, condition monitoring is an asset itself. The present paper presents the common faults on electric machines, their effects, their impact on the industry and the main techniques on condition control to prevent them. It is also added the reflection on the use of IoT to enhance the potential of condition control maintenance. The implementation of continuous improvement actions throughout the life of the equipment allows to increase efficiency, either by overcoming weaknesses or by adapting production or operational capacities to processes, production or maintenance, avoiding under maintenance or over maintenance and minimizing operating costs.info:eu-repo/semantics/publishedVersio

Recent progress in turbine blade and compressor blisk regeneration

The regeneration process of jet engines is a highly complex, expensive and time-consuming. Especially the regeneration of high pressure turbine blades and compressor blisks are at the border of what is technically feasible. These components are highly loaded and thus substantial wear occurs. The blades and blisks must be overhauled or replaced regularly. The existing repair methods for these parts are inflexible and cannot be applied in many cases, resulting in a large number of scrapped parts. Therefore a new turbine blade regeneration process is presented. The goal of the improved process is to reduce the scrap rate and cost. This process includes an early evaluation of the condition of the hot-gas path components before disassembly, new detection methods for defects on the turbine blades surfaces, and more flexible manufacturing processes. The process is supported by production process simulations and functional simulations to predict the optimal regeneration path depending on the blade condition and the business model of the customer. The paper also presents a new approach for compressor blisk regeneration. This process will be developed and validated in the next years. New challenges in structural mechanics, aerodynamics, and manufacturing must be addressed due to the complexity of blisks. As part of the ongoing research, three new blisks will be designed and subjected to the complete regeneration path, which is also supported by simulations. In order to validate the simulations, their results will be compared to experimental results of the regenerated components on a compressor test rig.DFG/SFB/87

Aeronautical Engineering: A special bibliography with indexes, supplement 48

This special bibliography lists 291 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1974

Recent advances in active infrared thermography for non-destructive testing of aerospace components

Active infrared thermography is a fast and accurate non-destructive evaluation technique that is of particular relevance to the aerospace industry for the inspection of aircraft and helicopters’ primary and secondary structures, aero-engine parts, spacecraft components and its subsystems. This review provides an exhaustive summary of most recent active thermographic methods used for aerospace applications according to their physical principle and thermal excitation sources. Besides traditional optically stimulated thermography, which uses external optical radiation such as flashes, heaters and laser systems, novel hybrid thermographic techniques are also investigated. These include ultrasonic stimulated thermography, which uses ultrasonic waves and the local damage resonance effect to enhance the reliability and sensitivity to micro-cracks, eddy current stimulated thermography, which uses cost-effective eddy current excitation to generate induction heating, and microwave thermography, which uses electromagnetic radiation at the microwave frequency bands to provide rapid detection of cracks and delamination. All these techniques are here analysed and numerous examples are provided for different damage scenarios and aerospace components in order to identify the strength and limitations of each thermographic technique. Moreover, alternative strategies to current external thermal excitation sources, here named as material-based thermography methods, are examined in this paper. These novel thermographic techniques rely on thermoresistive internal heating and offer a fast, low power, accurate and reliable assessment of damage in aerospace composites

A review of infrared thermography applications for ice detection and mitigation

Ice accretion on various onshore and offshore infrastructures imparts hazardous effects sometimes beyond repair, which may be life-threatening. Therefore, it has become necessary to look for ways to detect and mitigate ice. Some ice mitigation techniques have been tested or in use in aviation and railway sectors, however, their applicability to other sectors/systems is still in the research phase. To make such systems autonomous, ice protection systems need to be accompanied by reliable ice detection systems, which include electronic, mechatronics, mechanical, and optical techniques. Comparing the benefits and limitations of all available methodologies, Infrared Thermography (IRT) appears to be one of the useful, non-destructive, and emerging techniques as it offers wide area monitoring instead of just point-based ice monitoring. This paper reviews the applications of IRT in the field of icing on various subject areas to provide valuable insights into the existing development of an intelligent and autonomous ice mitigation system for general applications

Damage Tolerance Assessment Branch

The Damage Tolerance Assessment Branch evaluates the ability of a structure to perform reliably throughout its service life in the presence of a defect, crack, or other form of damage. Such assessment is fundamental to the use of structural materials and requires an integral blend of materials engineering, fracture testing and analysis, and nondestructive evaluation. The vision of the Branch is to increase the safety of manned space flight by improving the fracture control and the associated nondestructive evaluation processes through development and application of standards, guidelines, advanced test and analytical methods. The Branch also strives to assist and solve non-aerospace related NDE and damage tolerance problems, providing consultation, prototyping and inspection services