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A new 3-GeV synchrotron light source, NanoTerasu, started user service in April 2024 to provide highly brilliant soft to tender X-rays as complementary partner of SPring-8 which mainly covers hard X-rays in Japanese photon science platform. The present maximum stored current is 200 mA at top-up mode with current fluctuation of 0.5%. The horizontal and vertical emittances are roughly 1.1 nm.rad and 0.02 nm.rad, respectively, with 200 mA. More than 1,500 hours of scheduled user time were performed by August 2024 with high beam availability of 99.5% and long mean time between failures (MTBF) of 220 hours. The first phase 10 beamlines (BLs) are composed of two multi-pole-wiggler (MPW) BLs for hard X-rays, two in-vacuum undulator BLs for tender X-rays and five APPLE-II undulator BLs and a twin helical undulator BL for EUV and SX regions. The seven BLs are in operation for users for various experiments such as imaging and three BLs are under commissioning. This paper describes commissioning and user operation status of NanoTerasu accelerator system.

In this paper, we shall describe the reliability function R(t) as probability that the system will not malfunction within a given interval of execution times for maintained systems. Although, we shall be concerned with developing the reliability functions and predicted time to equipment breakdown (MTTF), Time between failures on average (MTBF) and the overall repair time (MTTR) from concepts of Markov model and some of transformations of Laplace to obtain the reliability and availability.

This paper briefly introduces the maintainability design and human factors of civil aircraft, emphasizes the accessibility design of the Line Replaceable Unit (LRU), and puts forward that the method of judging accessibility only by virtual simulation fails to fully prove whether the aircraft design meets the requirements of 25.611 of the airworthiness clauses. Combined with the Mean Time Between Failures (MTBF) and maintenance interval of the LRU, an innovative accessibility design method for civil aircraft system equipment based on 25.611 terms is proposed, and an example is given to show the application of the method. This method improves the maintainability design level of the main manufacturer and the market competitiveness of aircraft products.

As one of the most widely used metal tube bending methods, the rotary draw bending process enables reliable and high-precision metal tube bending forming (MTBF). The forming accuracy is seriously affected by the springback and other potential forming defects, of which the mechanism analysis is difficult to deal with. At the same time, the existing methods are mainly conducted in offline space, ignoring the real-time information in the physical world, which is unreliable and inefficient. To address this issue, a digital-twin-enhanced (DT-enhanced) metal tube bending forming real-time prediction method based on multi-source-input multi-task learning (MTL) is proposed. The new method can achieve comprehensive MTBF real-time prediction. By sharing the common feature of the multi-close domain and adopting group regularization strategy on feature sharing and accepting layers, the accuracy and efficiency of the multi-source-input MTL can be guaranteed. Enhanced by DT, the physical real-time deformation data are aligned in the image dimension by an improved Grammy Angle Field (GAF) conversion, realizing the reflection of the actual processing. Different from the traditional offline prediction methods, the new method integrates the virtual and physical data to achieve a more efficient and accurate real-time prediction result, and the DT mapping connection between virtual and physical systems can be achieved. To exclude the effects of equipment errors, the effectiveness of the proposed method is verified on the physical experiment-verified FE simulation scenarios. At the same time, the common pre-training networks are compared with the proposed method. The results show that the proposed DT-enhanced prediction method is more accurate and efficient.

The nacelle system, as one of the critical components of civil aircraft, is used to house the aircraft’s engine, providing structural protection, aerodynamic optimization, and facilitating ground maintenance. Its reliability is directly related to the flight safety and operational efficiency of the aircraft. With the continuous development of the national civil aviation industry, research on the reliability technology of civil aircraft nacelle systems has become particularly important, emerging as a significant research direction in the field of aeronautical engineering. This paper focuses on the reliability study of civil aircraft nacelle systems, establishing a failure FTA diagram, exploring and studying the prediction methods for reliability indicators such as DR, SR, and MTBF of civil aircraft nacelle systems, and conducting quantitative estimates of equipment-level reliability. This provides a theoretical reference for further research on the reliability and safety of civil aircraft nacelle systems in China.

The Synchrotron Light Source PETRA III at DESY is one of the most brilliant storage-ring based X-ray sources for high-energy photons worldwide, which offers scientists unique X-ray experiments in a wide range of fields since 2009. The light source is operated mainly in two operation modes with 480 and 40 bunches at a beam energy of 6 GeV with a maximum beam current of up to 120 mA. High reliability is one of the key requirements for a synchrotron radiation facility. The key performance indicators, availability and mean time between failures (MTBF), could be significantly improved during the operation periods of the last years. As the final milestones of the extension project that started in 2014, a new undulator was installed for the beamline P62 in the Paul P. Ewald hall in 2020, and a new dipole beamline (P66) have been installed in the North East section of PETRA III in 2021.

CNC machine tools, as key equipment in modern manufacturing, have reliability that directly affects machining quality, production efficiency, and total life cycle cost. Addressing the challenges of insufficient failure data for highly reliable CNC machine tools and the difficulty of applying traditional assessment methods, this paper proposes a reliability assessment method based on multi-axis machining accuracy degradation data. A 3000-hour on-site tracking test was conducted to systematically collect time-series machining accuracy data of the machine tool in single-axis and multi-axis coordinated motion directions. The Wiener process was used to establish degradation trajectory models for each accuracy indicator, from which pseudo-failure times were derived. Subsequently, the Weibull distribution was employed to fit the pseudo-failure time series, achieving quantitative reliability assessment of the whole machine. The results show that this method effectively addresses the assessment challenge posed by insufficient failure data. The established Weibull model shows significant fitting performance, with a Mean Time Between Failures (MTBF) of 2045.32 hours. Contribution analysis reveals that multi-axis coordinated motion accuracy has the most prominent impact on overall reliability, with the combined contribution of XZ, XYZ, YZ, and XY coordination accuracies reaching 69.56%. This study provides theoretical basis and methodological support for condition awareness and predictive maintenance of highly reliable CNC machine tools.

Minimizing total system failure could improve the reliability of power network in order to optimize power system operation. In this way, reliability analysis has been proposed by researchers to tackle the mentioned problem. This paper investigates an analytical methodology for reliability assessment and failure analysis techniques in an actual distributed power system. We use reliability analysis to evaluate system design and gathering outage data in this paper. Modelling and simulation of our assumed system are implemented in electrical transient analyzer program (ETAP) software. The results of theoretical/practical reliability and failure analysis including mean time between failure, mean time to repair, availability, system average interruption frequency index, system average interruption duration index, consumer average interruption duration index, average service availability index, average service unavailability index, expected energy not supplied, expected interruption costs, and interrupted energy assessment rate are compared with the summary of reliability assessment simulation. The capability and effectiveness of reliability evaluation are demonstrated according to the simulation results through ETAP which obtained by applying it to this power system.

Given the pressing need to strengthen operational reliability in electrical distribution networks, this study proposes an optimization methodology based on the Teaching–Learning-Based Optimization (TLBO) algorithm for the strategic location of redundant lines. The model is validated on the “MV Distribution Network—Base Model” test system, considering the combination of the MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) indicators as the objective function. After 500 independent runs, it is determined that the configuration with three redundant lines identified as LN_1011, LN_1058, and LN_0871 offers the most stable solution. Specifically, this topology increases the MTBF from 403.64 h to 409.42 h and reduces the MTTR from 2.351 h to 2.306 h. In addition, significant improvements are observed in the voltage profile and angle, along with a more balanced redistribution of active and reactive power, more efficient use of existing lines, and an overall reduction in energy losses.

The 4-leg inverter can adjust the load current or output voltage even under unbalanced load conditions, but it is known that the additional switch arm to the 3-leg inverter can increase the overall cost and the failure rate. This paper aims to analyze the failure rate and mean time between failures (MTBF) of 3-leg inverters and 4-leg inverters using part count failure analysis (PCA) and fault-tree analysis (FTA), and to compare the price of the inverters. The FTA can analyze the failure rate, including the type, number and connection status of the circuit components, and moreover the redundancy effect of the 4-leg inverter. For more accurate failure-rate prediction, the failure rate and MTBF of the 4-leg inverter according to the lifecycle of the controller are analyzed. Finally, by comparing the price of 3-leg inverters and 4-leg inverters using the cost model of major parts, the degree of reliability improvement against price increase is quantitatively analyzed.