Browse Topic: Reliability

Items (3,682)
Tackling the heavy computation of affine formation control under switching topologies—rooted in frequent stress matrix recalculation—this paper presents a distributed control framework fusing consistency estimation with dynamic error constraints for efficient coordination. In a leader-follower architecture, affine transformation parameters are estimated by followers using local information—global stress matrix solutions are thus avoided. A time-varying constraint function and Lyapunov stability analysis are devised to ensure tracking errors converge to specified accuracy within a predetermined time. Both theoretical analysis and simulation results show that this method greatly simplifies computation. It also supports flexible formation transformations such as translation and scaling, making it a stable and reliable solution for dynamic scenes.
Liu, GuicaiLi, JianzhenZhou, JunyiTang, Jiye
As system automation advances, the impact of human factors on human-machine system reliability becomes increasingly prominent. Given that the metro train dispatch system is central to metro operations, analyzing its human reliability aspects is crucial. Although human factor reliability analysis techniques have matured in fields like nuclear power and aviation, research on human-factor reliability analysis for metro train dispatch systems remains in its infancy. Based on this, the study proposes a method for identifying factors influencing human-factor reliability in metro train dispatch systems using exploratory factor analysis, grounded in survey data on such factors. Second, based on the identified factors, a structural equation model was constructed to identify the importance of human reliability factors in metro train dispatch systems. Through goodness-of-fit evaluation, the causal relationships among these factors were ultimately determined. The study indicates that individual, organizational, equipment, and environmental factors are the primary influences on human reliability in metro train dispatch systems, with 20 observable sub-factors under these main categories. The structural equation model results indicate that the relative importance of the four primary factors on human-factor reliability in the metro train dispatch system is: organizational factors > personal factors > equipment factors > environmental factors. This suggests organizational factors exert a relatively greater influence on human-factor reliability. This research provides a basis for enhancing the safety level and management decision-making of metro train dispatch systems.
Li, XinWang, LiangTang, ShuoYao, Zhenxing
In reliability evaluation of RV reducers using accelerated degradation tests, practical constraints (e.g., test costs and resource shortages) often lead to insufficient test iterations or small sample volumes. This results in limited insights into the product’s overall degradation trajectory, inadequate data for reliability analysis, and notable epistemic uncertainty. Conventional accelerated degradation models—rooted in probability theory—depend on the large numbers, rendering them ill-suited to address such uncertainty in small-sample scenarios. Uncertainty theory, a modern mathematical framework developed to characterize epistemic uncertainty, has garnered broad academic interest for its strong adaptability to small-sample contexts. Accordingly, this study explores the evaluation of RV reducer reliability using accelerated degradation data and uncertainty theory, aiming to mitigate epistemic uncertainty arising from small sample sizes. Specifically, this work develops a transmission accuracy degradation model for RV reducers based on the Liu process—a core component of uncertainty theory—that incorporates both inter-sample individual variability and the epistemic uncertainty inherent in the degradation process. This study also assesses the reducer’s reliability and service life; comparative analysis against probability-theoretic models confirms the proposed model’s advantages in small-sample scenarios.
Luo, MinHuang, JinxingDai, JinzhenShu, Ke
In recent years, China's urban rail transit sector has undergone rapid expansion, with passenger demand consistently increasing. Accurate passenger flow forecasting is essential for ensuring efficient and safe metro operations. This paper takes Nantong Metro Line 1 as a case study and applies an optimized forecasting approach that integrates a grey metabolism model with the Holt double-parameter exponential smoothing method. Based on an analysis of Automated Fare Collection (AFC) data from March 2023 to February 2024, passenger flow on this line demonstrates a clear linear growth trend, which aligns well with the assumptions of the grey metabolism model. The results indicate that the optimized grey metabolism model not only significantly enhances prediction accuracy but also greatly reduces the variance ratio, demonstrating high reliability in forecasting outcomes. This improved methodology provides a more robust tool for metro operators in planning services, managing capacity, and optimizing resource allocation.
Fan, FanZhao, ZehengZhang, JinMa, JunhaoQian, Beiyue
One challenge in railway operation is how to achieve high levels of punctuality and reliability. However, especially in peak hour operation, a high volume of train traffic will affect timetables, which are more sensitive to the increase in travel time. The concept of virtual coupling has been introduced for controlling train movement mainly to increase capacity. As the operation under virtual coupling requires a short separation distance between trains, it might be applied to reduce the delay and recover the train timetable. However, there is no approach proposed detailing how the coupling is applied to reduce delay. In this paper, the virtual coupling state movement approach based on a vehicle following model with the coupling conditions determined to couple a group of trains for reducing or preventing secondary delay is proposed. The train operation under the proposed approach is simulated in MATLAB software, then applied to the hypothetical case, High-speed line, Bangkok - Nakhon Ratchasima, Thailand. The delay analysis is performed, and the waiting probability is determined to prove the effectiveness of the proposed approach. The simulation results show that trains will be virtually coupled with their front train as a form of train convoy when they cannot proceed at the ideal speed. Thus, operating train movement based on the proposed approach can reduce secondary delay and bring a train to arrive on time compared to the operation under the moving block control.
Chansong, SukanyaKetphat, Naphat
J1979 DBCJ1979DBC_2026099/7/2026
The SAE J1979 DBC file contains decoding rules for converting raw J1979 data to 'physical values' (Mph, %, etc.). This file lets you easily decode data from heavy duty vehicles (trucks, buses, tractors, etc.). This DBC file download includes: The SAE J1979 DBC file with Includes 2,400+ Parameter Group Numbers (PGNs) and 16,000+ Suspect Parameter Numbers (SPNs), derived from the J1979-2 released in September 2026. One legal license (1 user, 1 PC) matching the DA license DECODE J1979: Convert J1979 data in wide range of software/API tools REVIEW FIRST: Use our CAN ID converter to check if your PGNs are covered CROWD INPUT: Benefit from free corrections based on large user base SAVE HOURS: Avoid manually constructing the DBC file from scratch Improved Accuracy & Reliability A fully standardized DBC file ensures precise signal decoding, eliminating errors and ensuring reliable data interpretation. Interoperability Seamlessly compatible with many different software stacks, enabling frictionless adoption and significantly expanding market reach. Partnership with Vector Informatik GmbH Works seamlessly with Vector’s free software (CANdb++), used by over 90% of the industry, with free download link provided on SAEI’s J1979DBC file landing page. What is a DBC file? A DBC file is a standardized method for storing the "rules" on how to interpret raw CAN bus data. It contains details on what 'signals' (e.g. RPM, Vehicle Speed, …) are contained within which 'messages' (i.e. CAN IDs). In the J1979 standard, messages are referred to as Parameter Group Numbers (PGN) and signals as Suspect Parameter Numbers (SPN). Further, a DBC file includes names, descriptions, positions, and lengths of the signals - as well as how to offset & scale them.
Assessing the vulnerability of bridges to traffic loads is critical for ensuring their long-term operational safety. The reliability of bridges under design vehicle loads or simulated random traffic flows constitutes the primary focus of existing research. Current research often lacks analysis that incorporates actual traffic load conditions. This paper proposes a traffic-load fragility assessment method for prestressed concrete hollow slab bridges considering load characteristics. The methodology integrates Metropolis-Hasting sampling algorithm with Copula functions to simulate random traffic flow, calculates resistance levels corresponding to structural cracking, yield, and failure states, and employs Monte Carlo sampling for failure probability calculation. Finally, a case study of four prestressed concrete hollow slab bridges is conducted to analyze their traffic load fragility. The results show that, under the same traffic load characteristics, different bridges have varying vulnerabilities corresponding to different failure states. The traffic-load fragility assessment approach put forward in this study can offer important technical support for both bridge design work and the development of vehicle load restriction policies.
Zhou, YihangYang, Gan
In the context of aerospace development towards lightweight, high reliability, and long life directions, such materials have become the core materials of key load-bearing structures for advanced aircraft, and their structural dynamic characteristics are directly related to the flight safety and service stability of the aircraft. This article uses uniform artificial springs to simulate the stiffness coupling effect and boundary conditions of the entire structure. In the stage of theoretical modeling, classical shell theory is used, and orthogonal polynomials are introduced as displacement functions. Is solved by the Lagrange energy equation. On this basis, the effect of external size parameters on structural vibration frequency is deeply discussed. With the change in structural natural frequency with the taper of the conical shell, the ratio of cylindrical shell length to diameter and the ratio of diameter to thickness are analyzed.
Zhao, YunhaoChen, Jie
Driven by the stringent service conditions of aviation, aerospace, and military equipment, parallel seam welding, as an advanced resistance-welding packaging process, has been widely applied in ceramic-metal packages that require high hermeticity, owing to its excellent sealing performance and reliability. In this study, targeting the hermeticity failures that appear in parallel seam-welded ceramic packages after temperature cycling, molecular dynamics simulation is used to systematically investigate helium diffusion in nanoscale interfacial microchannels and its effect on hermeticity. On the LAMMPS platform, a three-region model is constructed that includes a helium-charging region, a wall-channel region composed of Fe, Ni, and Au, and a vacuum leak region. The Lennard-Jones potential is used to describe interatomic interactions, and a thermal-cycling environment conforming to MIL-STD-883, with a temperature range from -50°C to +125°C, is simulated to represent actual service conditions. The simulation results show that when the channel diameter is less than or equal to 1.2 nanometers, the number of leaked helium atoms remains constant at approximately 22 and is not affected by temperature; when the diameter is greater than or equal to 1.6 nanometers, the leakage exhibits significant temperature dependence. For example, in a 2.6-nanometer channel, 212 atoms leak at 423 K and 176 atoms at 223 K. Both leakage flux and leak rate increase markedly with channel size. OVITO analysis confirms that helium diffusion exhibits molecular-flow characteristics; at very small apertures, atomic escape efficiency is limited by the frequency of collisions with the wall. These findings provide insight for improving hermetic packaging and reliability of critical electronics used in aviation, aerospace, and military equipment.
Li, XiangyangGong, YubingZheng, Xianling
The stress servo mechanism (SSM) is frequently employed in DEM simulations, but the importance of the parameters in the SSM has been seriously underestimated, and it remains unknown whether this affects the reproducibility of numerical simulations. Therefore, in this note, we focus on explaining the stress servo mechanism in numerical simulations by referring to the existing literature. A series of drained biaxial compression simulations was conducted to investigate how the maximum stress servo velocity (umax), a key parameter within the SSM, influences both the macroscopic mechanical response of the specimen and the evolution of the measured confining pressure. It is found that when the umax is large (≥ 0.05 m/s), the simulation results are consistent with the existing studies and are able to reproduce the stress-strain behaviour of the material. Conversely, if umax is set below a critical threshold (e.g., < 0.05 m/s), the servo mechanism fails to function properly. This inadequacy introduces significant numerical artifacts, distorting the simulated response and ultimately misrepresenting the true mechanical behavior of the material. We therefore advocate for the explicit recognition and detailed reporting of umax as a key parameter in all DEM studies utilizing stress servo control. This study helps to improve the reliability of DEM results and provides a reference for the improvement of numerical simulation methods.
Huang, GuangjingJin, JiachengHuang, Liang
This study investigates the cracking problems observed on the surface of T-joint welds and shell welds of storage tanks used for storing crude oil containing trace amounts of hydrogen sulfide (H2S) in a certain oilfield. Tests were conducted on Q235 and Q345R welded joints using electrodes with different hydrogen contents to evaluate their susceptibility to cold cracking, hydrogen-induced cracking (HIC), and sulfide stress corrosion cracking (SSC), as well as the effects of post-weld hydrogen removal treatment. The results show that no delayed cold cracks occurred in any welded joints of either Q235 or Q345R. Both materials exhibited hydrogen-induced cracking (HIC) on the cross-section, and the hydrogen removal treatment had little effect on improving HIC resistance. The overall HIC sensitivities of Q235 and Q345R were similar, both showing susceptibility to hydrogen absorption and internal cracking in the wet H2S environment. In contrast, SSC tests revealed that low-hydrogen welds exhibited no fractures or cracks, whereas high-hydrogen welds developed surface cracks. After hydrogen removal treatment, no SSC cracks were found in any specimens, regardless of electrode type. Therefore, for storage tanks operating in H2S-containing environments, the combination of low-hydrogen electrodes and post-weld hydrogen removal treatment is recommended to improve weld reliability and ensure operational safety.
Kang, ChunDeng, YufaZhang, PenggangHan, XiaochunHuang, MingjiDeng, BanghuiLi, QiangZhang, Shuxin
Fracture failure of girth welds in high-grade steel pipelines poses a critical threat to pipeline integrity. Leveraging enhanced digitalization in pipeline engineering, a statistical database has been developed to support reliability analysis based on actual operational data. This study utilizes real project data to analyze the failure probability and key influencing factors of girth welds containing crack defects, thereby providing theoretical support for safety design and risk management. To overcome the conservatism of traditional deterministic methods, a probabilistic reliability model was established, incorporating a modified PRCI-CRES ultimate tensile strain criterion. Addressing the inefficiency of standard Monte Carlo (MC) simulation in high-dimensional low-probability contexts, an efficient Hamiltonian Monte Carlo-Subset Simulation (HMC-SS) strategy was introduced. Results show that HMC-SS improves computational efficiency by 99.95% over MC, with only 0.90% relative error. Key findings include: crack depth has the strongest influence – variation from 0.92 mm to 3.68 mm, which increases failure probability by 103 times; the strength matching coefficient is dominant, and higher values reduce failure risk; strain demand exhibits a positive correlation with failure probability and couples with material properties. It is concluded that high- or equal-strength material matching should be emphasized in welding, and reliability-informed design should account for multi-parameter interactions to ensure global safety.
Yang, KaiWang, KaihongWang, BinShao, JiaYu, WeichaoZhang, Dong
For vibration issues induced by coupling effects between flexible barrel guide mechanisms and moving bodies in high-speed dynamic systems, this study investigated their interaction mechanism using flexible multibody dynamics principles. A solid model was developed in 3D CAD software. The modal neutral file (MNF) of the guide mechanism was generated in ABAQUS, and its contact dynamics with the moving body were simulated in ADAMS via flexible contact theory and the modal superposition method. Comparative simulations revealed that incorporating structural flexibility yielded smoother fluctuations in the moving body’s axis inclination angle, providing more accurate system behaviour characterization. Exit velocity and spin rate errors remained below 5% against theoretical values, demonstrating model reliability.
Zhu, QingCheng, ZixiangZhuo, Changfei
Effective shock absorption is essential for maintaining stability during landing events. Aerospace systems traditionally rely on oleo-pneumatic struts, while robotic platforms utilize lightweight compliant joints for impact mitigation. Recent advances have shifted attention toward adaptive solutions, including magnetorheological and electrorheological dampers, which can adjust their damping characteristics in real time through sensor feedback and control algorithms. By integrating established mechanical design principles with advanced materials and intelligent control strategies, modern landing systems can achieve improved energy dissipation and enhanced performance under variable and unpredictable conditions. This work evaluates the transition from passive to adaptive shock absorption technologies by examining landing dynamics, the mechanical architectures of conventional and semi-active systems, and the control strategies that enable adaptive damping. The findings indicate that, although passive systems offer reliability and simplicity, they lack the adaptability required for highly variable environments, while semi-active systems provide enhanced performance through real-time modulation enabled by advanced control algorithms. However, challenges related to power requirements, system complexity, material durability, and long-term reliability continue to limit widespread implementation of adaptive technologies. Overall, this review highlights the limitations of passive designs, evaluates the tradeoffs between MR and ER damping technologies, examines the evolution of semi-active control strategies, and identifies the key technical barriers that must be addressed before adaptive shock absorption systems achieve broader operational adoption.
Shah, RajeshPatel, ParthMittal, Vikram
Corrosion-wear damage behavior affects the bearing life and reliability seriously in a corrosive environment. The accurate evaluation of the tribocorrosion behavior of 8Cr4Mo4V bearing steel samples is critical for the application and protection of bearings. The present work seeks to establish the relationship between laboratory salt spray accelerated experiments and the corrosion of 8Cr4Mo4V steel samples in real outdoor marine atmosphere exposure, and investigate the tribological behavior in the corrosion-wear process under artificial seawater. Results show that salt spray corrosion tests can well simulate the corrosion of 8Cr4Mo4V steels in marine atmospheric exposure. The tribocorrosion performance of 8Cr4Mo4V steels under artificial seawater conditions is affected by the temperature effect of the corrosive liquid and the working conditions. Increased normal load and reduced rotational speed can improve the anti-friction performance. This work offers the possibility and reference of precise control of corrosion-wear-coupled damage failures for bearings.
Zhao, ChaoYing, LixiaNie, ChongyangZhu, TianlinSun, Dong
In the conversation surrounding electrification, the vehicle itself typically dominates the headlines. But those operating on remote jobsites in the mining, construction and agriculture sectors know the machine is only half the equation. These industries prioritize reliability and uptime and require machines that can handle grueling shifts in demanding environments without compromise. Power providers in these heavy-duty, off-highway markets must move beyond the battery itself to explore a holistic approach to infrastructure when it comes to powering remote jobsites. The first step to success is understanding the fundamental differences between off-highway duty cycles and on-highway applications. While on-highway applications like long-hauling trucks benefit from steady-state operation and passive airflow for cooling, off-highway machines often operate at high torque for extended periods, with little to no forward movement. In these scenarios, there is no passive cooling to rely on or regular refueling stations at the next exit. Success, therefore, is defined by the engineering required to ensure that electric machines deliver the same productivity as diesel, even when operated at their limits in the most rugged, remote conditions.
Moore, Preston
For decades, hydraulic systems have been relied upon to do all the heavy lifting in aerospace. They are powerful, reliable, and deeply embedded in how aircraft are designed, to the extent that - for many engineers - they are simply part of the landscape. Now, however, things are beginning to change. From advanced air mobility platforms now entering certification to next-generation commercial aircraft on 10-year horizons, electric and electro-hydraulic actuation is steadily replacing the heavy, centralized hydraulic architectures that have defined flight control for decades. Understanding why means stepping back from the actuator itself and looking at the aircraft as a whole system - and, increasingly, as an integrated motion control challenge.
With the continuous development of large precision equipment, the reliability requirement for long-distance transportation is also constantly increasing. Large packaging box with sealing and vibration reduction performance is crucial during transportation. This article introduces the sealing measures for large-sized packaging box, as well as the sealing structure design methods for key parts, vibration reduction measures and the selection and design of vibration dampers. The designed packaging box has been used for long-distance transportation of various types of equipment and the reliability of sealing and vibration reduction performance has been verified in practical applications, providing reference for the design of similar packaging boxes.
Zhang, RuoyuJiang, Shouli
Recent advances in precision motion technology have heightened the requirement for precise stiffness analysis in flexible mechanisms. This paper begins with a theoretical analysis, constructing a mathematical expression for the stiffness of flexible mechanisms, providing a systematic framework for analysis. Subsequently, the study employed finite element analysis on both single and double parallelogram flexible mechanisms to validate the proposed theoretical stiffness formulas. This process not only confirmed the effectiveness of the proposed expressions but also highlighted the influence of different structures on stiffness characteristics. The finite element analysis results validate the proposed theoretical model as an effective and reliable tool for predicting the stiffness of flexible mechanisms. By establishing a reliable predictive model, this research paves the way for the informed design and systematic optimization of next-generation flexible mechanisms in precision motion engineering.
Cai, Dongchen
To address the challenge of accurately assessing the reliability of complex equipment, a reliability evaluation system for a five-axis machining center was developed based on extension theory. By collecting and analyzing the failure modes and data of various subsystems, the strengths of the Fuzzy Analytic Hierarchy Process (FAHP) and the Entropy Weight Method (EWM) were combined to determine the weight of reliability evaluation indicators for both the machining center and its subsystems. A comprehensive assessment of the five-axis machining center's overall reliability was conducted. According to the principle of maximum membership, the reliability grades for the spindle system and the feed system were both rated as “excellent.”
Fei, ShouxiangWang, DechaoPiao, ChengdaoZheng, Shengkui
Fleet heterogeneity, from manufacturing variations and diverse operating conditions, complicates reliability analysis by obscuring true failure patterns in aero-engines. This is a critical challenge in an industry as inaccurate Mean Time Between Failures (MTBF) estimates threaten safety and inflate operational costs, by forcing a choice between inefficiently conservative maintenance or the risk of in-service failures. Conventional analysis often fails by pooling all fleet data. To address this, our paper presents an analytical framework that improves predictive accuracy by filtering, rather than aggregating statistical noise. The methodology uses a Randomized Block Design (RBD) and ANOVA hypothesis test to screen a diverse dataset and isolate statistically homogeneous subgroups. This filtration identifies a core fleet with a consistent failure signature, providing a purified dataset for modeling. This refined data is then modeled using both Weibull and the Exponentiated Inverse Weibull distributions to ensure the results are robust and not model-dependent. Applying this framework to a 25-engine dataset that experienced 66 failures, we isolated a stable failure pattern, yielding a primary MTBF of 171.16 hours and a cross-validated MTBF of 176.35 hours. The close 3% convergence between these models validates our approach. By providing a dependable MTBF, this work establishes a stronger foundation for data-driven Reliability Centered Maintenance (RCM). It empowers maintenance planners to move toward evidence-based intervals, safely extending engine time-on-wing, optimizing spare parts inventory, and significantly reducing direct operational costs for airlines.
Jubaid, Mayin UddinBebe, GibsonBigyen, Musa PethuelAnik, S M Kullul MehedeeYasmin, AshrafiSahran, Mohamed Sideek Mohamed
This study presents a systematic investigation into the assembly stress and fatigue life of 60-series harmonic reducers. A sophisticated finite element simulation model is constructed to precisely simulate the real assembly process and calculate stress distribution in the flexspline under axial assembly errors. In addition, corresponding fatigue life tests are designed to explore the influence of different axial assembly errors on the number of rotation cycles and transmission efficiency of the harmonic reducer. By comparing the predictions of the fatigue life mathematical model with the test data, a reliable fatigue life prediction method is established, providing a solid theoretical basis for the whole-machine assembly process and reliability design of this series of harmonic reducers.
Du, YuefeiQiu, HaodongFan, YongLi, ZiyuanDong, YiZhang, ChiLi, ChenzhengLi, Yuan
In the process of replacing the rollers of the fabric cart of the tobacco storage cabinet, in order to solve the problems of low replacement efficiency and high safety risk.This article proposes a specialized lifting tool for fabric cart rollers with a self-locking and adopts the screw lifting structure, which facilitates roller maintenance operations, and conducts SolidWorks Simulation calculations and dynamic simulation methods. Jinan Cigarette Factory fine cigarettes special line leaf silk temporary storage cabinet fabric car roller replacement, for example, the results show that: the average operating personnel reduced by 50%, the replacement time from 6.7h to 1.2h, efficiency increased by 458%, This innovation significantly reduces the labor intensity of maintenance personnel and ensures a safe and reliable replacement process.
Zhang, LeiXue, YifeiZhang, GeSun, YanzhaoWang, HongbinCheng, Linfeng
Reliability evaluation aims to quantify the reliability level of equipment and to verify its compliance with reliability requirements. Existing reliability evaluation methods primarily rely on operational phase data, which means reliability evaluation may lag behind actual needs. In practice, both users and design teams are more concerned with how to estimate CNC machine tools’ reliability before they are put into operation. Moreover, current reliability evaluation methods usually ignore the design team’s influence on CNC machine tool reliability. To overcome these limitations, this study proposes a novel reliability evaluation method that accounts for the influence of the design team on the reliability of CNC machine tools. By analyzing the impact of the design team’s technical capabilities and reliability capabilities on CNC machine tool reliability, a set of quantifiable evaluation indicators was established. Then, the weight coefficients of all indicators were determined using the expert scoring method. Finally, all data were integrated using the vector projection method, which enabled a quantitative reliability evaluation of CNC machine tools from different design teams within the same category. Additionally, the proposed method was applied to conduct practical case studies on multiple CNC external cylindrical grinding machine tools designed by different design teams, thereby validating the feasibility of the proposed method. The reliability evaluation results not only determine the reliability level of each CNC machine tool but also identify the weak points in the technical capabilities and reliability competencies of each design team. This study concludes by discussing the significance of this approach for enhancing the reliability capabilities of design teams and its practical implications for end users.
Sun, DongyangZheng, WeixuChu, HongyanXu, JingjingCheng, Qiang
In port construction, high-pile wharves—a primary structural form—are constantly exposed to marine environmental erosion, making corrosion a particularly prominent issue. Traditional anode installation typically relies on underwater diving operations, which suffer from low efficiency, high risks, and significant costs. To address these challenges, a novel installation technique requiring no divers has been developed. Through specialized equipment design and optimized construction processes, this technology enables remote, efficient, and safe anode installation. Research focuses on the design of non-diver anode support installation equipment, safety validation, and construction methodologies. Through theoretical analysis, numerical simulation, and field construction trials, this technology significantly enhances construction efficiency while reducing operational risks and costs. It provides a reliable solution for corrosion protection in high-pile wharves and holds significant importance for advancing port construction technology.
Lan, JinpingZhang, Shoulong
Transporting large steel materials for mountain electric towers is challenging due to steep gradients, narrow roadways, and uneven terrain. To address these issues, this study designs an adaptive attitude adjustment mountain transport vehicle. This mountain transport vehicle has a compact structure, measuring 1.4 meters in length and 1.1 meters in width, which enhances its suitability for confined mountainous environments. This vehicle adopts a design scheme that combines hydraulic lateral adjustment, load-bearing platform follow-up adjustment and frame adaptive adjustment mechanisms. The transportation of tower materials, measuring 12 meters in length and 1.2 tons in weight, is accomplished by employing two vehicles working in coordination. The three-dimensional model of the entire vehicle is established by using SolidWorks software. The lateral stability of the mountain vehicle and the limit working conditions of its adjustment mechanism are analyzed through theoretical calculation. The dynamic simulation of the virtual prototype is carried out using Adams software, including the processes of lateral leveling, follow-up adjustment and frame adjustment. The results show that the leveling mechanism can achieve an adjustment range of more than ±25°. The results confirm the vehicle’s excellent stability and adaptability to mountainous conditions. This study provides a more effective and more reliable solution for the construction of mountain electric towers than traditional manual or animal-powered transportation methods.
Zhang, RuiKong, FanfangHe, YulingLv, JiahuiChen, ChanglongZhan, LulinLiang, Ke
Ball screws, as classic high-precision transmission structures, are widely used in various linear motion mechanisms. To meet the needs of space applications, it is necessary to address issues such as microgravity and long lifespan to enhance the in-orbit lifespan and reliability of ball screws. Traditional oil or grease lubrication methods are often unsuitable for space environments due to microgravity and vacuum evaporation problems. This paper conducts relevant research on lubrication design, friction pair design, and friction and wear verification to solve the lubrication and lifespan issues of long-lifespan ball screws for space applications.
Xie, WenZhao, JianGong, KangHu, XiaonanGuo, MengleiJiao, Hanyu
The climb gradient along the takeoff trajectory at each point during takeoff reflects the aircraft’s ability to clear obstacles and reach a safe altitude, ensuring the safety of civil flights. Airworthiness regulations specify certain requirements for the single-engine-out climb gradient. Given that the data used in conventional calculation methods are significantly influenced by the flight status during the process, this paper explores two new climb performance calculation methods based on the existing ones. A set of data was calculated, and the resulting errors were all no more than 10%, indicating that both new calculation methods are effective and reliable. Therefore, they provide a certain reference value for the climb gradient calculation of transport category aircraft.
Jiang, TianjunLiu, Tao
Multi-UAV cooperative localization can utilize information fusion between nodes to improve localization accuracy and performance on the target. Distributed state fusion estimation methods have been heavily studied in recent years, but the final estimates in the research results do not converge towards the global optimum. This paper aims to make the state estimates of each individual in the UAV formation for the target converge and converge to reliable values. In this paper, we study a multi-UAV cooperative tracking method based on adaptive weighted fusion, which first evaluates the importance of each node in the UAV formation and the reliability of the local filtering estimation results, and then assigns the weights according to the reliability of the UAV’s local state estimation of the target in the whole at the current moment. Finally, this paper verifies through simulation experiments that the method can not only accomplish the state tracking of the target, but also that the state estimates of each node in the network converge to more accurate state estimates.
Xia, ShengjiWang, ChangqingLiu, FaleiJia, ZhaoxuanZhao, Quanpu
Craters are the primary landmarks used for visual navigation in missions exploring small celestial bodies. However, obtaining high-quality, annotated crater data is often challenging due to limited imaging conditions and strict mission constraints. Conventional semantic segmentation models struggle with limited data and are challenging to train effectively. To overcome this limitation, this study introduces a few-shot segmentation approach for crater detection on small celestial bodies. Our method includes a prototype representation module that constructs class-level prototypes to quickly associate crater regions with their semantic features. This paper also designs an iterative learning module that gradually improves the segmentation output, helping the model better capture detailed edges and structures. Tests on a simulated few-shot dataset demonstrate that our method provides reliable and accurate crater segmentation, achieving a mean intersection-over-union (mIoU) of 88.7, outperforming traditional fully supervised methods.
Li, ShuaiZhu, Shengying
Requirements of Interface for Aircraft/Store Electrical Interconnection System (GJB 1188A-99) is the current standard followed by all types of carrier aircraft and stores. This paper designed a 1553B bus remote terminal mode code configuration method that met the requirements of GJB1188A standard, completing the interrupt initialization and data initialization of compulsory mode codes. These comprehensive test results confirm that the proposed mode code configuration method is both reliable and effective, and provides strong portability, which can be used as a reference for the GJB1188A interface software design of other components
Han, BinZhang, KunLiu, XuhanYe, JinhanLi, Zhengmao
This document contains information and guidance on assessment of the risk posed by observed tin whiskers for aerospace, defense, and high-performance (ADHP) products or other products that demand high reliability.
G-24 Pb-free Risk Management Committee for ADHP
The reliability of aviation maintenance personnel directly impacts flight safety, yet systematic methodologies for the quantitative prediction of human error probability (HEP) in this domain remain lacking. To address this gap, a novel human factors reliability analysis method for aviation maintenance is proposed, extending the SPAR-H model through Evidential Reasoning (ER). This method is implemented as follows: Maintenance tasks are decomposed into subtasks. Subsequently, the eight types of Performance Shaping Factors (PSFs) for each subtask are evaluated by domain experts according to defined PSF levels. Expert judgments are then aggregated using Evidential Reasoning theory, enabling the calculation of aggregated PSF levels. These aggregated levels are interpolated to determine the corresponding impact multipliers. Finally, the HEP for aviation maintenance operations is calculated by integrating the SPAR-H basic error probability model with task series/parallel logic rules. The proposed methodology is validated using an inspection operation case study. This study establishes a methodological framework for human factors reliability analysis in aviation maintenance, providing a theoretical foundation for developing scientifically grounded prevention and control measures to enhance aviation safety levels.
Meng, MengMa, NingGuan, ZhongqingHan, ZuyangNan, WenxueCai, Hongbin
Vehicle vibrations during precision instrument transport can cause damage and failure. Existing vibration isolators often lack reliability, mass production feasibility, and easy maintenance. In this paper, we design and analyze a quasi-zero-stiffness vehicle-mounted isolator with an inerter, decreasing dynamic stiffness while raising the effective mass. Theoretical, simulation, and experimental results show improved isolation performance, lower isolation frequency, and a broader isolation bandwidth.
Li, KaiLv, SiboSun, NingDai, Shijie
The gearbox is a key component of the mechanical transmission system, and its fault diagnosis is essential to the reliability of the equipment. However, obtaining fault samples under actual working conditions for gearbox fault diagnosis is challenging. In this paper, the rigid-flexible coupling dynamic simulation model of the gearbox is established, and the co-simulation of gear normal, crack, and breakage is carried out in the ADAMS and MATLAB environments. The comparison between the simulated and measured signals shows that the simulation method can accurately reflect the key characteristics, such as rotation frequency and meshing frequency, and verify its reliability and accuracy. The research results can provide effective data support for gearbox fault diagnosis and improve the operational safety of mechanical systems.
Li, DongxiaoZhang, QianqiZhang, ZhongzhengLi, Yongbo
The magnetic field modeling methodology for ships based on magnetic dipole arrays demonstrates heightened sensitivity to input data. When addressing overdetermined systems characterized by numerous variables and constrained measurement points, the coefficient matrix frequently develops pathological ill-conditioning, leading to solution divergence and compromised result accuracy. This research reformulates the ship magnetic field inversion challenge as a non-convex quadratic programming problem, employing the Successive Convex Approximation (SCA) algorithm as the computational solver. Rigorous comparative validation was performed against conventional stepwise regression algorithms and experimental datasets acquired from scaled ship model measurements. Results substantiate that while the modeling precision of the SCA algorithm remains comparable to that achieved by stepwise regression methods, SCA exhibits demonstrably superior solution stability. This enhanced robustness positions SCA as a more reliable computational framework for critical naval applications, particularly in high-fidelity ship magnetic signature modeling and rapid detection/localization of magnetic targets in marine environments.
Chen, HaoPan, Xun
Aiming at the problem of insufficient modeling of spatio-temporal heterogeneity in road traffic accident prediction, a dual task machine learning framework integrating geographical environment, location attributes and time periodicity is proposed. The dataset used in this study was derived from traffic accident records of Nanchang during 2019–2023. Firstly, geographical identifiers are generated by rounding and aggregating latitude and longitude coordinates. At the same time, the location type is processed by a one-hot encoding, so as to carry out spatial clustering analysis of accident hotspots. Compared with the North-South pattern, the contribution of geographical features shows a strong East-West trend. The kernel density heatmap identified Zone A and zone B as dual core high-risk areas. Secondly, the sinusoidal/cosine function is used to encode the time feature circularly, which effectively captures the daily change of the accident. The quantitative analysis of random forest regression model showed that time characteristics accounted for 89.2% of the variance of accident frequency interpretation, significantly exceeding the contribution of geographical factors (10.2%) and location attributes (0.6%). After hyperparameter optimization, the accuracy of XGBoost classifier in predicting serious accidents is 75.97%, and the AUC value is 0.8412, which has strong robustness, and provides reliable support for dynamic risk assessment of traffic management system.
Luo, JiangZhang, YuxinLi, XinWu, Ronghai
Medical device manufacturing is undergoing a structural shift. As devices become smaller with broader functionality, traditional approaches to assembling electronics are no longer sufficient. Increasingly, performance, durability, and reliability are dictated not just by design, but by how that design is manufactured.
Robotic manipulation remains one of the harder unsolved problems in automation engineering. Vision-based systems have matured considerably — object localization, pose estimation, and grasp planning from RGB-D data are now reliable enough for structured industrial environments. What vision cannot provide is contact information: whether a grasp is stable, whether a surface is beginning to slip, or how force is distributed across a fingertip during a hold. These signals are what close the control loop during manipulation, and without them, systems compensate through excessive grip force, conservative motion profiles, and large training datasets designed to paper over sensing uncertainty.
Traditional industrial robotics has been built on traditional premises: define the task precisely, program the motion, and repeat it with minimal variation. This model has delivered reliability, speed, and scale across multiple application domains.
To minimize noise caused by interior components rubbing against each other, automotive materials are usually tested in advance with the established stick-slip method according to VDA standard 230-206. This procedure is widely used for soft materials, upholstery and plastics. However, it is limited to constant climatic and selected loading conditions. Contrary, in real application, changing climates and dynamic excitations can nevertheless trigger noise issues even in materials rated as suitable in the prior tests. To address this gap, a new test method has been developed that evaluates the stick-slip behavior of material combinations for a wide range of loading and climatic conditions. Conducted in a climate chamber with a standard stick-slip test bench, the procedure applies sinusoidal excitations, dynamic climatic shifts and advanced data analysis. In addition to the usual results the new method also evaluates realistic scenarios such as starting a vehicle in different seasons or sudden jolting movements with high excitation speeds. The result is a detailed map of stick-slip behavior as a function of excitation speed and climate. While requiring a similar level of effort as the traditional test, this approach delivers far greater insight. It enables a more reliable optimization of materials and facilitates targeted material selection for specific applications. In this manner, it can not only contribute to improve product quality but also to achieve quiet interiors and customer satisfaction.
Fritz, SusanneStrangfeld, Martin
Abstract: This research paper investigates the performance of FKM (Fluorocarbon) seal material when exposed to a 50:50 ethylene glycol-water mixture. The study aims to determine the volume change percentage and Hardness change of FKM elastomers under standardized testing conditions. The experimental approach follows ASTM D471 and ASTM 2240 guidelines, focusing on weight and hardness measurements of the test samples to establish a success criterion. The results provide critical insights into the chemical compatibility and durability of FKM elastomers in Aerospace and industrial applications where ethylene glycol-water mixtures are commonly used. The findings contribute to enhanced material selection and design considerations for sealing applications subjected to glycol-based fluids. Samples of FKM material were immersed in the fluid at controlled temperatures and durations, simulating real-world operational conditions. The primary metric of interest, volume change percentage and Hardness change, were assessed through precision measurement techniques. Weight changes before and after immersion were also recorded to correlate material absorption characteristics with the success criteria. Success thresholds were established based on industry requirements for seal integrity and operational reliability. Preliminary results indicate that FKM exhibits minimal volume expansion and hardness change under specified conditions, aligning with the acceptance criteria. These findings support the suitability of FKM seals for long-term use in coolant systems, with implications for material selection and design in demanding applications. This research contributes to the development of durable sealing solutions, ensuring reliability and safety in systems utilizing ethylene glycol-based coolants. Keywords: FKM, Volume Expansion, ASTM D471
Yarolkar, MakrandPatil, SandipSingh, Tanul
The mechanical performance of short fiber-reinforced plastic (SFRP) components is highly sensitive to fiber orientation, which is significantly influenced by the injection gate location during the molding process. Traditionally, gate placement decisions are driven by warpage minimization strategies, often overlooking mechanical performance under diverse load cases. This research introduces an automated workflow within Digimat-MS that integrates injection gate optimization into the early design phase, leveraging Integrated Computational Materials Engineering (ICME) principles. The proposed methodology enables engineers to upload either Marc, Abaqus or Ansys input decks, select a component of interest, assign material cards, and define gate scenarios. A Design of Experiments (DOE) is then executed locally or remotely, allowing Digimat to evaluate multiple gate configurations. The system aggregates results and identifies optimal gate locations based on the initiation of failure under quasi-static loading conditions, thereby reducing reliance on trial-and-error and expert intuition. This approach not only streamlines the simulation process but also ensures that gate placement decisions are informed by comprehensive mechanical assessments across multiple load cases. The integration of Digimat’s ICME capabilities enhances simulation accuracy, leading to improved reliability and performance of SFRP components.
Kauthale, TanmayMadhavan, VinaySoni, Ganesh
Using vibration data to estimate buckling loads is proven effective for a wide range of structures, including rods, plates, and shells. The Arbelo formulation of the vibration correlation technique improves prediction reliability for cylindrical and spherical shells. In this study, we introduce a simplified variant of the Arbelo approach that provides higher prediction accuracy while requiring significantly lower pre-load levels. We define a new parameter, the Stiffness Decay Index (SDI), to characterize stiffness degradation by normalizing the loaded natural frequency with respect to the unloaded state. This metric enables accurate buckling prediction without causing structural damage or permanent deformation. We evaluate SDI numerically and experimentally for multiple isotropic geometries and demonstrate its advantages over the Arbelo method, particularly for ellipsoidal domes subjected to external pressure. We conduct experiments on rods, plates, oblate shells, and beverage cans to measure frequency shifts under pre-loading. The results show that when load data above 50% of the critical value is available, the SDI approach predicts the buckling load with accuracy exceeding 90%. These findings confirm that SDI, by directly correlating vibration response with stiffness loss, provides superior buckling-load prediction and serves as a reliable, non-destructive alternative to the Arbelo vibration-correlation method.
Rangarajan, GopikrishnaV, VishwajithRaju, GangadharanDinavahi, Ramkrishna
A new DC-DC power converter is superior to previous designs and paves the way for more efficient, reliable, and sustainable energy storage and conversion solutions. The Kobe University development can efficiently interface with a wide range of energy sources while enhancing system stability and simplicity at an unprecedented efficiency.
Designing the next generation of wireless wearables, implantables, and real-time external or in-body monitoring devices is a complex challenge that requires highly reliable electronic components that greatly exceed the performance of standard commercial alternatives.
Ultra-miniature sensors are enabling advanced procedures and treatments across a wide range of medical devices, from catheters and neuro interfaces to wearables. But as electromagnetic sensors get smaller, trade-offs begin to emerge — lower sensitivity, less tolerance for environmental influences, and greater susceptibility to interference — underscoring the need for robust testing to ensure accurate, reliable tracking.
This SAE standard establishes the requirement for suppliers to plan a reliability program that satisfies the following three requirements: a The supplier shall ascertain customer requirements b The supplier shall meet customer requirements c The supplier shall assure that customer requirements have been met
G-41 Reliability
The sag prediction of overhead ground wire is very important, because excessive sag will reduce the safety margin and endanger the transmission reliability, especially under extreme conditions such as heat wave and icing. To solve this problem, we propose a model that combines Exponential Moving Average (EMA) features and monotonic constraints XGBoost. By fusing multi-source meteorological data and sag monitoring data, sag-related features are extracted after outliers elimination and time alignment. Furthermore, EMA features are introduced to capture short-term fluctuations and time dependence. Monotonic constraints encode the physical prior knowledge of “the higher the temperature, the greater the sag”, which improves the physical interpretability. On the measured data, the model’s coefficient of determination is increased from 0.709 to 0.879, indicating that the short-term prediction accuracy is significantly improved. The combined application of EMA features and monotonic constraints can maintain the physical consistency and enhance the time learning ability, which provides a feasible scheme for intelligent sag prediction of transmission lines.
Li, XingyuLin, ShizhongShao, ZhanCui, ShichengChen, RuiduanLuo, He
This study investigates the use of the Overset mesh method for propeller simulations in OpenFOAM and compares it with the Arbitrary Mesh Interface (AMI) approach. While AMI is well validated for rotor aeroacoustics, it is limited in handling large relative motions and complex component interactions. In contrast, the Overset method enables flexible simulation of transition kinematics using overlapping grids, though its aeroacoustic capability in OpenFOAM has not been well established. A comparative analysis was conducted on a Joby-scale five-bladed propeller at an 80° tilt angle without a fairing, representing a transition-flight condition. Aerodynamic and acoustic predictions were obtained using hybrid DDES coupled with the Ffowcs Williams–Hawkings method. Results show that the Overset method provides improved agreement with experimental thrust and torque and captures stronger leading-edge vortices than AMI. Both methods resolve blade-vortex and blade-wake interactions. However, the Overset approach produces higher broadband noise due to stronger vortices and interpolation effects, while AMI yields smoother pressure fields and clearer tonal content. In the far field, AMI better matches experimental SPL trends. Overset shows larger first-BPF SPL errors (up to 22.5 dB vs. 5.7 dB for AMI), though OASPL differences remain small. Overall, Overset is less reliable for noise prediction and more computationally expensive.
Hua, JieMankbadi, Reda R.Lyrintzis, Anastasios S.Golubev, Vladimir
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