Browse Topic: Electrical, Electronics, and Avionics

Items (59,496)
Find
J1979 DBCJ1979DBC_202609To be published on 09/07/2026
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.
Ultrasonic Guided Wave Thickness Measurement of Cortical Bone with Soft Tissue2026-99-12209/4/2026
Early diagnosis of osteoporosis is crucial for preventing fractures and improving the quality of life of patients. In clinical practice, the mainstream diagnostic methods, such as dual-energy X-ray absorptiometry (DXA), are limited by high equipment costs and ionizing radiation, resulting in a low coverage rate of large-scale early screening. Only less than one-third of brittle fracture patients have received a DXA assessment. To address this issue, this study proposes an innovative diagnostic method based on ultrasonic guided wave technology. This technology is cost-effective and portable, and it overcomes the limitations of X-ray detection in terms of its unsuitability for large-scale early diagnosis. The Young’s modulus and Poisson’s ratio of water are similar to those of soft tissue, so this method utilizes water coupling to simulate the environment of soft tissue around the bone and combines the transverse isotropy of cortical bone, which is an important characteristic that most existing models ignore, to analyze the propagation of guided waves in anisotropic cortical bone. Through the processing of ultrasonic signals using two-dimensional short-time Fourier transform (2D-STFT), the local thickness of cortical bone can be inverted. By establishing a fluid-coupled orthotropic anisotropic plate model, deriving the dispersion equation, solving the theoretical method for the dispersion curve, using the bovine long plate to construct a water-coupled detection platform, and obtaining experimental data to invert the thickness of the bone plate, the local thickness of the bone plate was obtained, proving that this method can effectively reconstruct the thickness changes of anisotropic and variable cross-section cortical bone under simulated soft tissue conditions, with an average relative error of 13%. This lays the foundation for subsequent in vivo experiments and provides a reliable solution for large-scale early osteoporosis screening.
Nong, Kexin, Li, Bing
A Novel Physics-Informed Graph Convolutional Reduced-Order Model for Fluid Flow on Unstructured Meshes2026-99-12459/4/2026
This study proposes a physics-informed graph convolutional reduced-order model, namely Phys-GCN, for high-fidelity and computationally efficient prediction of steady incompressible flow fields. In Phys-GCN, the incompressible Navier–Stokes equations are embedded into the loss function via residual constraints, such that the spatial feature extraction of graph convolutional networks is integrated with the physics-constrained learning strategy of physics-informed neural networks. This mixed design enables the model to capture complex nonlinear flow features while maintaining a clear level of physical interpretability. Benefiting from the node-edge encoding inherent to graph neural networks, Phys-GCN operates directly on unstructured CFD meshes to learn flow features from graph representations constructed using node attributes and adjacency relationships. In doing so, Phys-GCN dispenses with voxelization or SDF preprocessing and fully preserves the local geometric and topological characteristics of the flow domain. The proposed model is systematically evaluated on steady flows past circular and elliptical cylinders, where the predicted velocity and pressure fields are compared against reference CFD solutions in both interpolation and extrapolation scenarios. Results show that, for all physical quantities, the reconstructed steady flow fields achieve mean relative errors below 5%, exhibiting excellent agreement with the CFD benchmark solutions. After offline training, Phys-GCN achieves inference times that are several orders of magnitude faster than conventional CFD solvers, while maintaining comparable predictive accuracy. These findings demonstrate that Phys-GCN provides an accurate and efficient graph-based and physics-informed surrogate for steady flow-field reconstruction on non-uniform, unstructured meshes, thereby laying a solid foundation for future extensions to more complex three-dimensional and compressible flow configurations.
Xie, Haoran, Zhou, Hao, Yu, Changhao, Li, Qiang, Liu, Tianyu, Peng, Jiangzhou
Dynamic Characteristics Analysis of Needle Roller Bearings in Planetary Gear Trains with Consideration of Inner Bore Spalling Defects of Planet Gears2026-99-12799/4/2026
Driven by the growing demand for higher efficiency and load-bearing capacity in fields such as new energy vehicles and heavy-duty engineering machinery, planetary gear sets are increasingly operating at elevated rotational speeds, coupled with a corresponding expansion of their revolution radii. This dual trend directly induces a substantial surge in centrifugal acceleration acting on the internal needle roller bearings. Under the cyclic stress inherent to transmission operations, such enhanced acceleration not only accelerates the initiation of spalling faults on the inner bores of planet gears but also exacerbates the propagation and deterioration of these faults throughout the service life. To elucidate the influence mechanism of inner bore spalling on the dynamic response of planetary gear bearings, this study develops a specialized dynamic model. This model explicitly incorporates the compound kinematic effects of simultaneous rotation and revolution, thereby ensuring a high-fidelity reconstruction of actual operating scenarios. The research systematically investigates how different spalling types and dimensional parameters affect the system’s dynamic behavior. Numerical results demonstrate a positive correlation between the severity of the spalling defect and the dynamic response intensity. Specifically, the expansion of defect dimensions under harsh operating regimes markedly exacerbates both the contact impulses at the needle-roller interface and the overall vibration acceleration amplitudes. Notably, the amplitude increment of the needle rollers is far more pronounced than that of other components. These findings enrich the theoretical understanding of fault-induced dynamic responses in planetary gear systems and provide a solid theoretical and model-based foundation for optimizing the fault diagnosis, condition monitoring, and maintenance strategies of the associated needle roller bearings.
Zou, Desheng, Lai, Junbin, Guo, Wei, Dong, Peng, Xu, Xiangyang, Sun, Qiang
A Coaxiality Measurement Method Applicable to the Three Holes of an Engine2026-99-12269/4/2026
To address the measurement challenges posed by the large diameters and wide spans of engine crankshaft holes, cylinder holes, and camshaft holes, as well as the abnormal laser measurement data caused by oil film adhesion and local protrusion structures on their inner walls, this paper proposes a non-contact coaxiality measurement method based on a laser displacement sensor (LDS) and a threshold-modified least squares ellipse fitting (TMLSE) algorithm. The method first preprocesses the data through median filtering and then employs an adaptive distance threshold based on maximum inter-class variance to eliminate outliers caused by oil film scattering and protrusions, achieving robust fitting of the cross-sectional centers. Subsequently, the datum axis is established using the least squares midline method, ultimately enabling the evaluation of coaxiality error. In the simulation experiments, a dual-hole model with an inner diameter of 100 mm and a spacing of 700 mm was simulated, where the right hole was translated by 1.5 mm to introduce coaxiality error. Each cross-sectional point cloud included 10% protrusion points (protrusion height of 10 mm) along with random noise and data loss simulating the effects of oil film. To assess the robustness of the method, a systematic analysis was conducted on the influence of laser incidence angles [80°,89°]on measurement accuracy. The results show that across different incidence angles, the maximum deviation between the coaxiality error obtained by the TMLSE method and the theoretical value is only 0.1582 mm, which is significantly better than that of the RANSAC, MZC, and MIC methods. Meanwhile, TMLSE demonstrates stable and efficient computational speed. The simulation verifies that this method offers higher fitting accuracy and robustness under both optical interference and variations in installation angle, making it suitable for the precision measurement of key engine hole systems.
Yin, Jiakuo
Research and Analysis of Civil Aircraft Radio Altimeter Malfunction2026-99-12359/4/2026
The radio altimeter is an important navigation instrument on an aircraft, capable of accurately measuring the aircraft's true height above the ground or sea to ensure safe flight. This capability is crucial for ensuring normal flight operations, especially during critical phases such as takeoff, approach, and landing. Polar terrain is complex and continually changing. The vast, endless ice fields, crisscrossing glacier crevasses, towering icebergs, and weather conditions all add significant uncertainty to air travel. In such environments, the aircraft's navigation system is particularly important as a core device to ensure flight safety. This article provides a brief overview of the aircraft radio altimeter system. Using data and observations from production flight tests, it studies the specific challenges posed by radio altimeter failures encountered during these critical validation flights. The study synthesizes these findings and proposes a relatively general troubleshooting approach to address such issues. Furthermore, the effectiveness of this method has been rigorously validated through its application in solving a complex real-world radar altimeter failure case.
Song, Mingming, Mi, Yujie
Strain Analysis of Buried Pipelines in Trench Models Crossing Strike-Slip Faults2026-99-12809/4/2026
Long-distance buried pipelines are the core type in pipeline transportation; the technical indexes and requirements for protection are stricter. In the previous coupling model of pipe and soil, the in-situ soil and backfill soil are treated as a unified continuous medium, and the actual geometric shape and boundary effect of the pipe trench are ignored through simplification of the calculation model. In this study, a new coupling model of in-situ soil, backfill soil, and pipeline is proposed to analyze the actual strain state of buried pipeline with different backfill soil and in-situ soil materials. A model was established based on the ANSYS software to simulate and investigate the mechanical behavior of strike-slip fault-crossing buried pipelines under real trench conditions. By varying multiple parameters, this study analyzes the effects of different operating conditions on the strain distribution and magnitude of buried pipelines. The findings of this study can serve as a reference for the design, construction, and protection of buried pipelines traversing active faults.
Li, Yuxiang, Wang, Guang, Zhang, Chengbin, Wang, Ke, Bi, Haisheng
Simulation and Structural Optimization Design of Thermal-Mechanical Coupling Performance of Supporting Components2026-99-12939/4/2026
This research aims to develop a high-performance composite material support component that meets extreme performance requirements. It is used to solve the problem of protecting critical electronic control units (ECUs) and flight data recorders in aerospace and automotive safety systems under harsh combined conditions of high temperature and high shock. Its internal dimensions are 0.14 m × 0.08 m × 0.08 m. In addition, it is required to withstand a constant temperature of 65°C for 3600 seconds, with the internal core temperature not exceeding 35°C. It can withstand a static load of 1.8 kg and a transient impact acceleration of 1400 G. The dual-layer composite structure based on functional decomposition solves the problems of thermal insulation and load-bearing/impact resistance. The inner layer uses ultra-low thermal conductivity aerogel to form a thermal barrier. The outer layer is a load-bearing frame made of high-strength/high-modulus quartz fiber reinforced epoxy composite material. The study employs a systematic numerical simulation method to verify the optimized design parameters. The results show that the internal temperature remained stable at 34.173°C. The outer layer deforms only at the micrometer level under static load. The inner layer is under zero load and there is no distortion in the internal space. The integrated design method of “material-function-structure-simulation” proposed in this paper provides a research approach for the survivability design of mechanical structures of new-generation aircraft and ground vehicles under complex multiphysics constraints.
Liu, Jiaxin, Wang, Yi, Zhao, Xiaorong, Wu, Chaofu, Zhao, Zhuo, Chen, Long
High-Precision Micro-Satellite Attitude Control: Design and Testing of an Ultrasonic Motor-Driven Control Moment Gyroscope2026-99-12919/4/2026
The issues associated with the traditional single-gimbal control moment gyroscope (SGCMG) driven by electromagnetic motors, such as complex structure, significant gear backlash, weak anti- interference capability, poor adaptability to space environments, and large volume and weight, make it difficult to meet the attitude control requirements of micro/nano satellites. To address these issues, this paper proposes an SGCMG design based on a rotary traveling wave ultrasonic motor (RTWUM) drive. Ultrasonic motors offer advantages including high torque, fast response, self-locking upon power-off, immunity to electromagnetic interference, and simple structure, making them suitable for spacecraft attitude control systems. This paper elaborates on the working principle and structural design of the ultrasonic motor, covering the entire process from stator modal optimization, flywheel and gimbal structural design to system integration and control system implementation. Through finite element analysis and experimental verification, the designed ultrasonic motor-driven SGCMG meets the requirements of micro/nano satellites in terms of output torque, speed control accuracy, and structural compactness, demonstrating the promising application prospects of ultrasonic motors in aerospace attitude control.
Wu, Jintao, Zhang, Jiyang, Li, Huafeng, Pan, Song
Aerodynamic Load Calculation and Prediction Method for Folded Wing Mechanism2026-99-12899/4/2026
The folding wing mechanism is widely used in aircraft design. Whether the folding wing surface can unfold smoothly determines whether the aircraft can fly normally. Therefore, studying the aerodynamic loads and structural deformations during the unfolding process of folded wing surfaces is very important. The motion process of a folded wing mechanism is a typical fluid-structure interaction (FSI) process. During deployment, the wing surface moves under the combined action of the actuator’s pull and the aerodynamic loads from the incoming flow, while the large deformation of the wing surface during its movement, in turn, affects the aerodynamic loads on the mechanism from the flow field. Considering the FSI effects during the unfolded motion process of the folded wing, simulation was conducted using the ALE algorithm in LS-DYNA to obtain the kinematic and dynamic parameters in the unfolded motion process, and also to get the aerodynamic torque on the wing under different angles and angular velocities. In practical engineering applications, the actuation force of the deployment mechanism can vary due to factors such as the amount and performance of the pyrotechnic material. Consequently, the final velocity and the whole motion process of the wing mechanism will also change. For the calculation of aerodynamic external loads under multiple operating conditions, using the ALE algorithm will consume a large amount of computational time and cost. Given the high computational cost and long computation time of finite element simulations, a BP neural network was established to calculate the aerodynamic loads on the wing surface under different actuation forces. This allows for a rapid assessment of whether significant deformation or damage will occur to the folding mechanism or nearby components during the deployment process.
Wei, Ting, Li, Naitian, Tong, Zongkai
Numerical Investigation of Spiral Tubes and Turbulators for Enhanced Metal Hydride Reactors2026-99-12589/4/2026
Solid-state hydrogen storage is severely limited by poor thermal performance of storage reactors, which leads to non-uniform temperature fields and slow reaction kinetics. A numerical model for metal hydride hydrogen storage technology was implemented by means of COMSOL Multiphysics 6.3, based on hydrogen sorption behavior for LaNi5-based material. After experimental validation, a spiral-wound tube with embedded turbulators was introduced into the reactor. The influence of turbulator cross-sectional ratio and shape on hydrogen-absorption performance was then investigated. When the turbu-lator occupied 1/40 of the cross-section, the temperature distribution became more uniform and the reaction rate increased markedly; the time to achieve 80% conversion was reduced by approximately 9.29%. The study demonstrates that tailoring the turbulator geometry (circular vs. square) and exploiting its synergy with the spiral tube accelerates reaction kinetics and balances the temperature field. Under 0.8 MPa and 313 K, a hydrogen uptake of 1.4 wt% was achieved. The simple structure can be mass-produced by CNC (Computer Numerical Control) tube-bending, making it attractive as a portable hydrogen source for mobile devices such as unmanned aerial vehicles.
Lin, Jiangnan, Jin, Tingxiang
New Nonlinear Buckling Solutions of Piezoelectric Truncated Conical Shells2026-99-12629/4/2026
Piezoelectric materials are highly valued in engineering for their electromechanical coupling. With these characteristics, structural applications utilizing such materials are increasingly being employed across a variety of disciplines. Among these structural configurations, piezoelectric conical shells have garnered significant interest owing to their inherent electromechanical coupling behavior, making them ideal for applications in various devices such as actuation systems, sensing mechanisms and energy harvesting solutions. To ensure the structural safety of these devices, assessing the stability of such shell structures is essential. This study conducts an analysis of the buckling stability of truncated piezoelectric conical shells. To this end, a theoretical buckling model for piezoelectric truncated conical shells is established, based on first-order shear deformation theory combined with nonlinear pre-buckling deformations. Utilizing a novel set of displacement trial functions within the Galerkin framework, this study derives precise critical buckling loads along with their associated mode shapes. The accuracy of the model is verified through comparative studies in the numerical section. Subsequently, the influence of key parameters—including applied voltages, semi-apex angles, and shell thickness—on the buckling behavior is investigated. The findings indicate that including the nonlinear pre-buckling deformation in the analysis is essential for ensuring reliable predictions. This research offers a theoretical foundation for the dependable design and assessment of piezoelectric truncated conical shells. Moreover, they also create opportunities for smart structures in aerospace, civil, and robotics, where accurate predictions of stability under electromechanical loading are critical.
Zhang, Junlin, Chen, Lide, Jia, Jufang, Zhou, Zhenhuan
Ant Colony-Artificial Potential Field Fusion Path Planning Algorithm Based on a Maneuver Action Library2026-99-12579/4/2026
The traditional Ant Colony Algorithm has defects such as easy entrapment in local optima due to a simplistic heuristic function and slow convergence due to excessive search directions. A fusion path planning algorithm integrating ant colony optimization and artificial potential field based on a maneuver action library is proposed. Firstly, a mathematical model for UCAV path planning is established. Considering the maneuverability constraints of UCAVs, and drawing on the concept of basic maneuver action libraries for fighter aircraft, an ant colony-potential field fusion path planning algorithm based on a maneuver action library is introduced. Simulation results demonstrate that compared to two other algorithms, the proposed method significantly improves the number of waypoints and planning completion time.
Li, Ruishen, Chen, Xiaogang
Experimental Study on Heat Transfer Performance of Gravity Heat Pipes in Green Highway Construction2026-99-12399/4/2026
Gravity heat pipe technology offers an innovative solution for utilizing shallow geothermal energy to melt pavement snow and ice in winter, aligning with the requirements of green highway construction. By leveraging the evaporation and condensation of internal working fluids, these heat pipes efficiently transfer underground thermal energy to the ground surface, delivering a continuous and stable heat supply for road pavements in cold weather. To explore the factors affecting heat transfer efficiency, this study built an indoor environmental simulation platform and systematically examined the impacts of heat pipe shape, working fluid type (R-134a, R245fa), heating temperature (15°C–25°C), and working fluid filling rate (15%–30%). A winter pavement snow- melting simulation experiment was conducted to quantify key indicators such as pipe wall temperature and heat transfer power under medium-low temperature conditions. Experimental results show that R-134a heat pipes outperform R245fa counterparts in heat transfer power under simulated shallow geothermal snow-melting conditions. Low filling volumes tend to induce temperature gradients in the condensation section of L-shaped heat pipes, reducing overall efficiency. Straight heat pipes work best at a 15% filling rate, while L-shaped models achieve optimal performance at 25%. Comparative experimental analysis yielded parameter-effect diagrams for heat transfer power and thermal conductivity, which clarify the variation rules of heat pipe performance and provide engineering guidance for gravity heat pipe applications in green highway construction.
Wang, Zhen-kun, Yuan, Zhi-ming, Wang, Kang, Zhang, Wen-jun, Wu, Xiang-song, Liu, Guang-bo
Detection of Pipe Surface Coatings on Ultrasonic Guided Wave Propagation2026-99-12159/4/2026
Coating the surface of pipelines is one of the most crucial and effective methods for inhibiting corrosion and prolonging the operational lifespan of pipelines. The coating acts as a protective shield that isolates the pipeline metal from external corrosive environments. However, once the coating begins to peel off or deteriorate due to aging, mechanical damage, or environmental factors, the exposed metal surface becomes highly susceptible to corrosion. Statistics indicate that over 50% of external corrosion failures in pipelines are directly associated with coating defects. Despite the critical importance of coating integrity, research on the interaction between surface coatings and nondestructive testing methods—particularly ultrasonic guided wave techniques—has remained relatively limited in recent years. In this study, the impact of surface coatings on the propagation behaviors of ultrasonic guided waves in pipeline systems was systematically investigated. Coal tar pitch, a commonly used and cost-effective coating material, was applied to steel pipeline specimens with varying coating lengths. The attenuation rate of the guided wave signal amplitude was measured under different coating conditions to analyze the relationship between coating parameters and acoustic energy loss. The experimental results reveal that the coating significantly affects guided wave propagation, especially in terms of signal attenuation and boundary reflection. Furthermore, the study reveals that ultrasonical guided waves possess strong sensitivity to coating discontinuities and can accurately locate coating boundaries. These findings confirm the potential of guided wave technology for early detection of coating defects and quantitative evaluation of coating adhesion. Moreover, the outcomes provide useful insight for other transportation and aerospace structures that employ multilayer coatings or protective films, such as aircraft pipelines and composite fuselage components, where similar material interfaces and inspection challenges exist. This research provides theoretical and experimental references for improving the reliability of pipeline health status detection.
Xiao, Tianyi, Li, Bing
A Simultaneous Impulse and Oscillatory Component Decomposition Method for Fault Diagnosis of Rolling Bearings2026-99-12049/4/2026
Due to the interference of oscillatory components and noise, the periodic impulses associated with localized bearing faults become difficult to extract, leading to unreliable diagnostic performance. To solve this problem, the study proposes a simultaneous impulse and oscillatory component decomposition method (SIOCD). The method designs and solves a novel optimization model to decompose oscillatory components and fault impulse components from noisy vibration signals. To achieve component separation in the optimization model, distinct penalty functions are introduced for oscillatory and impulse components. For oscillatory components, a regularization term is applied to achieve their extraction by minimizing the component bandwidth in the frequency domain. For impulse components, a penalty function is designed to achieve their decomposition by enhancing both sparsity within groups (SWG) and sparsity across groups (SAG) in the time domain. Then, an iterative solver is derived using an alternating minimization framework and the majorization-minimization (MM) algorithm. Finally, the proposed method’s effectiveness is demonstrated through comprehensive simulation and experimental analyses, and the results demonstrate that it achieves superior performance over existing approaches in fault feature extraction and enhancement.
Sun, Haoran, Zhang, Jinduo, Han, Tianyu, Shi, Xi
Nonlinear Modeling and Parameter Identification of Air Rudder System2026-99-12129/4/2026
The modeling accuracy of the air rudder system directly affects the quality of aircraft attitude control. However, the commonly used simplified second-order model cannot accurately represent its nonlinear transfer characteristics. To this end, a dynamic model of the air rudder system considering three types of nonlinear factors, such as saturation, clearance, and dry friction, was established. On this basis, a stepwise identification test modeling method based on frequency characteristic data was proposed. By designing two different excitation levels of test conditions to excite or suppress the influence of some nonlinear factors, the stepwise identification of each unknown physical parameter was completed. The identification results show that the air rudder system model established in this paper can accurately characterize its nonlinear transfer characteristics, and the transfer characteristic curve of the identification results is in good agreement with the measured data.
Wang, Ding, Nangong, Zi-jun, Liu, Bo
Degradation-Based Reliability and RUL Prediction for Railway Wire Harness Connectors Under Multi-Temperature Conditions: An Adaptive Wiener-DGM Hybrid Model2026-99-12719/4/2026
Railway wire harness connectors are critical elements in modern rail transport systems, ensuring reliable signal transmission, power distribution, and communications across the subsystems that govern traction, braking, and passenger information. The progressive deterioration of these connectors under harsh operating conditions, particularly temperature variations encountered during continuous railway operations, poses significant challenges to system reliability and operational safety. This paper presents a hybrid framework integrating an adaptive Wiener process with a deep generative model (DGM) for reliability assessment and remaining useful life (RUL) prediction of railway wire harness connectors under multi-temperature conditions. The proposed methodology combines Arrhenius-based temperature acceleration with a Wiener degradation model that characterizes temperature-dependent degradation kinetics. Specifically, a variational autoencoder (VAE) is employed as the deep generative network to learn the complex nonlinear degradation patterns that conventional parametric models may fail to capture. Furthermore, a particle filter algorithm is incorporated to enable real-time Bayesian parameter updating and state estimation, thereby allowing the model to be refined in an adaptive manner as new monitoring data become available. The effectiveness of the proposed method is validated through accelerated degradation tests on electrical connectors at four temperature levels (25°C, 55°C, 85°C, and 105°C), demonstrating that the RMSE is reduced by 23.5%, 18.2%, and 32.1% compared with the standard Wiener process, LSTM-based approach, and Gaussian process regression, respectively. The analytically derived reliability function and RUL distribution provide comprehensive uncertainty quantification to support maintenance decision-making in railway systems.
Wu, Jiajun, Chen, Yongping
Assembly Accuracy Optimization of Aero-engine Section Based on Dynamic Weighting Multi-Objective Optimization Algorithm2026-99-12729/4/2026
The pose-solving method for aero-engine component docking assembly often faces challenges such as slow convergence and susceptibility to local optima when dealing with complex optimization problems involving multiple features and constraints. This paper proposes an optimized assembly pose solution method for engine sections based on an improved multi-objective optimization algorithm. The method first preprocesses the high-density point clouds obtained from 3D scanning to extract geometry such as feature points, lines, and surfaces. It builds an assembly constraint model with geometric relations and process needs. It focuses on the pose solution phase: we transform the assembly problem into a nonlinear optimization problem to minimize parallelism error, gap error, and step error. In order to solve this multi-objective problem efficiently, we propose an iterative multi- objective optimization algorithm as the optimization engine and propose a dynamic weight allocation strategy. During iteration, the strategy adaptively adjusts the weight coefficients of three error terms in the overall fitness function due to the evolution of the population and convergence of each error term, guiding the search direction and balancing the algorithm's global exploration and local exploitation ability. Our results show that instead of adopting an optimization algorithm with fixed weights and a multi-Objective optimization system with fixed weight, the proposed pose solution method based on dynamic weight multi- objective optimization algorithm achieves a high accuracy and stability of the solution and can easily and accurately produce a good pose matrix which meets challenging assembly constraints, providing a practical theoretical framework and technical support for achieving high-quality automated engine assembly.
Huang, Mi, Wu, Guanghui, Su, Xun, Xu, Yongqian, Ding, Han, Liu, Xiaopeng
Study on the Effect of NaNO 3 +NaClO 3 Electrolyte on the Corrosion Resistance of the Oxide Layer on M50 Aviation Bearing Raceway2026-99-12839/4/2026
In the electrochemical machining (ECM) process of the M50 bearing raceway, the oxide layer’s corrosion resistance exerts a notable impact on the machining efficiency. To achieve high-efficiency ECM of M50 bearing raceways, the electrochemical impedance spectroscopy (EIS) testing technique was adopted to conduct systematic research on the anti-corrosion performance of the oxide layer on M50 bearing raceways under different ECM processing parameters (polarization voltage, polarization time, inter-electrode gap). Then, the impact of different processing parameters on the oxide layer’s corrosion resistance was revealed. The results show that the corrosion resistance of the oxide layer decreases with the increase of the polarization voltage and polarization time, and increases with the increase of the interelectrode gap. Based on this law, in the actual ECM process, the rapid formation of oxide layer can be promoted by adjusting the polarization time, increasing the polarization voltage and reducing the interelectrode gap, and finally, the efficiency of ECM can be improved.
Wu, Jianxing
Johnson-Cook Model Calibration of 10# Steel and Dynamic Mechanical Behavior Analysis under High Strain Rates2026-99-12019/4/2026
As a typical material for fragmentation warheads, the mechanical behavior and ballistic penetration performance of 10# steel are critical for assessing warhead lethality. To characterize the dynamic response of 10# steel, systematic experiments were conducted, including quasi-static tensile tests, split-Hopkinson tensile bar tests, and thermal softening measurements. A = 505.46 MPa, B = 292.84 MPa, n = 0.335, C = 0.0343, and m = 1.213 are the calibrated Johnson–Cook parameters. Bridgman-corrected notched tensile tests determined damage parameters D1 to D4: 0.065, 0.746, −0.646, and 0.031). A study of its constitutive behavior shows that the strength of 10# steel increases with stress triaxiality and strain rate, whereas increasing temperature enhances ductility and reduces strength. Finite element software was updated to include the calibrated parameters to develop a material model for ballistic impact simulation. When compared with the ballistic penetration test results obtained using a 14.5 mm projectile, the simulated residual velocities show less than 5% deviation from the measured values. 3D scanning reveals that fragment sizes in experimental data differ by under 10% from simulation predictions. This work enables precise numerical simulations for warhead fragmentation prediction and lightweight armor design.
Tian, Yumo, Zhang, Longhui, An, Fengjiang, Feng, Bo
Molecular Dynamics Simulations of Microstructural Evolution in Pure Titanium under Laser Shock Peening2026-99-12859/4/2026
Impacts of laser shock peening (LSP) on the evolution characteristics of microstructure in commercially pure α-phase titanium (α-Ti) are explored by molecular dynamics (MD) simulations of high strain-rate compression. The EAM potential (Zhou potential) is selected for its ability to capture the evolution of microstructures. Considering the LSP-induced peak plasma pressure, the strain rate during the simulated shock compression process is set at 10^9 s-1 to replicate the LSP process. The stress-strain curve of the α-Ti under high strain-rate compression is obtained. The maximum equivalent stress reaches 3.6 GPa, consistent with the theoretically calculated value. The simulation results reveal that mechanical twins (MTs) are activated at a strain of 3%. The number of mechanical twins increases and eventually stabilizes, forming a network structure throughout the grains. In the meantime, numerous partial dislocations are generated adjacent to the grain boundaries. The dislocation density also increases with strain and dislocation reactions occur. Moreover, grain refinement is identified. The grain size is refined from the initial ~ 8 nm to ~ 4 nm in the polycrystalline α-Ti. Twinning, together with dislocation-mediated plasticity, drives the refinement of grain size. Gradients of twin density, dislocation density, and grain size density are induced by LSP on the surface of α-Ti. This study comprehensively investigates how LSP influences the evolution of microstructures by MD simulations. It develops an innovative numerical strategy that offers a foundation for elucidating the underlying mechanisms of LSP.
Zhao, Congshan, Zhang, Linbing, Xu, Yidi, He, Jianye, Fang, Jing, Li, Zezhou, Ruestes, Carlos J., Cheng, Xingwang
W60(FeCrNi2.5) Alloy with High Strength and High Adiabatic Shear Band Sensitivity2026-99-12439/4/2026
To meet the high-performance requirement of tungsten heavy alloys in kinetic energy penetrators under extreme dynamic loading conditions, high strength and high adiabatic shear band (ASB) sensitivity are essential. The formation and evolution of ASB during the penetration process directly dominate penetration capability of tungsten heavy alloys (WHAs). However, traditional WHA (93W) exhibits relatively low strength and adiabatic shear band insensitivity, which limits its applications in advanced kinetic energy penetrators. This study prepared W60(FeCrNi2.5) alloy by means of spark plasma sintering with 1~3 μm powders. The sintered alloy exhibits outstanding mechanical properties at quasi-static (0.001 s-1) and dynamic (4000 s-1) strain rates. Its yield strengths reach 1.5 GPa and 2.7 GPa respectively, manifesting a notable strain rate strengthening behavior. Dynamic compression tests indicate that the alloy generates ASB with a width of ~8 μm. Within the ASB, the body-centered cubic (BCC) phase is elongated to nanofibers under shear stress, and fine W particles are generated as a result of grain debonding in nanofibers. Meanwhile, the grains of the face-centered cubic (FCC) phase are disintegrated into subgrains due to dislocation pile-ups at subgrain boundaries, and new equiaxed grains are formed through subgrain boundaries rotation. The calculated adiabatic temperature elevation inside the ASB of this alloy reaches a maximum of 1315 K under 4000 s-1. Notably, its ASB sensitivity coefficient reaches 20.8, while that of the 93W alloy is 1.02. Thus, it achieves a favorable combination of high strength and high adiabatic shear band sensitivity, which offers meaningful references for advanced kinetic energy penetrator materials.
Lin, Jingchen, He, Jianye, Wang, Qiang, Wu, Shanghao, Zhang, Linbing, Ruestes, Carlos J., Li, Zezhou, Zhang, Zhaohui, Zhang, Fan, Wang, Lin, Cheng, Xingwang
Adaptive-Weighted Coupling-Aware Gaussian Processes for AFP2026-99-12779/4/2026
Composite materials have gained widespread application in the aerospace field due to their advantages, such as high specific strength, high specific modulus, and corrosion resistance. Automated placement technology, as an emerging automated manufacturing method, is gradually replacing traditional manual placement processes and demonstrating significant advantages in composite manufacturing. Currently, the automated placement process for composite materials faces challenges such as insufficient experimental samples and strong coupling relationships between process parameters, leading to low fitting accuracy in process parameter optimization models. To address this, this paper proposes a placement process parameter optimization method based on model weight adaptive allocation. This method integrates three key technologies: a coupling-aware Gaussian process based on combined kernel functions, a weight allocation ensemble model based on leave-one-out cross-validation, and a multi-criteria adaptive sampling mechanism. Experimental validation demonstrates that the integrated model achieves a coefficient of determination R^2 = 0.82, which represents a superior fit compared to the R^2 = 0.65 achieved by a single-kernel Gaussian model and the 0.76 obtained from a single sampling. Furthermore, both the Root Mean Square Error (RMSE=0.92) and Mean Absolute Error (MAE=0.70) are lower than those of traditional baseline models. This framework provides an effective solution for optimizing parameters in the automated placement process for composite materials.
Zuo, Rui, Du, Tingting, Lv, Ruiqiang
Design and Validation of a 7-DoF Robotic Arm Featuring Hybrid Pneumatic-Electric Actuation2026-99-12229/4/2026
To enable more natural motion mapping between the human arm and a robotic counterpart while reducing control complexity, this paper presents a novel seven-degree-of-freedom (7-DoF) bionic robotic arm with hybrid pneumatic–electric actuation in an antagonistic configuration inspired by the skeletal structure and muscular actuation of the human upper limb. The design combines the high power density and intrinsic compliance of pneumatic artificial muscles with the precision and stability of electric motors, improving motion adaptability and payload-to-weight performance. Kinematic feasibility and motion smoothness for human-like waving are validated via forward kinematics and redundancy-resolved inverse kinematics, together with trajectory simulations. To quantitatively evaluate dexterity and operational range, Monte Carlo sampling is used to generate reachable postures across the workspace, producing a wrist activity map that characterizes attainable orientations and maneuverability. A prototype testbed is built to verify physical performance. Joint-angle tracking experiments for the wrist and elbow, as well as whole-arm coordinated-motion tests, demonstrate accurate trajectory tracking, smooth transitions, and stable motion. These results confirm the mechanical soundness and effectiveness of the proposed hybrid antagonistic actuation scheme. This work provides a practical basis for advanced control development and offers insights into hybrid actuation design for bionic robotic systems.
Dai, Yuanquan, Guo, Zhiqin, Zi, Mingkang, He, Zhaoyang, Song, Yongwei, Xie, Yinhui, Li, Jun
Automotive Engineering: September 202626AUTP099/3/2026
Bespoke at scale: How generative AI is rewriting the economics of manufacturing automation The economic logic behind factory software upgrades is breaking down. Navigating an increasingly complex engine oil landscape As the impending ILSAC GF-8, dexos 1 Gen 4, and a hybrid specification continue to obscure the North American landscape, passenger car engine oils need additive solutions that can help simplify blending operations and optimize product portfolios. High-temperature joint reliability Why preload retention matters more than fastener grade. Designing out corrosion at the wheel The case for advanced powder coatings. Editorial Where to? The challenges of automated driving around the world The Navigator Is China really our biggest automotive security threat? Better safety through collaboration at Toyota research center ATS 2026: automated driving is changing The software-defined technician: Manufacturing's next human capital revolution Aumovio says system can BAC with non-invasive finger touch How conveyors have carved a role in mastering manufacturing 2027 Mercedes-Benz S-Class: Same as ever, which is very good 2026 Lucid Gravity: Highly efficient luxury hauler Product Briefs Spotlight: Adhesives and coatings; sustainable materials Q&A How an automotive startup uses and doesn't use customer data
Validation Study of the Jaguar Land Rover Aerodynamic Computational Fluid Dynamics Process Using Metric-Based Assessment Criteria2026-01-50729/3/2026
Credibility of simulation data has always been fundamental in aerodynamic vehicle development, as a significant amount of early design phase work is conducted virtually before a physical test property is made. As the automotive industry pivots toward artificial intelligence and machine learning techniques to assist in aerodynamic development, training these models with simulation data requires a comprehensive understanding of the accuracy and validity of the underlying simulation. It is critical these systems are trained from reliable data with a full understanding of both the limitations and predictive performance of the computational fluid dynamics (CFD) process and the wind tunnel facility it is benchmarked against. Validation and verification studies have been a long-established set of guidelines to determine if the simulation model appropriately reflects reality (validation) or if it has been set with robust numerical schemes, mesh settings, or boundary conditions (verification). The work presented here shows a comprehensive validation study with more than 400 test configurations and 18 vehicle properties. It evaluates Reynolds-averaged Navier–Stokes (RANS) and detached eddy simulation (DES) approaches using moving reference frame (MRF) and rigid body motion (RBM) to account for wheel rotation and comparing STAR-CCM+ CFD process and the FKFS Aeroacoustic Wind Tunnel (AAWT). The results demonstrate that DES—particularly when wheel rotation is modeled using RBM—provides the highest overall predictive performance, with a drag accuracy from −2% to +4% for 80% of cases with corrections applied, which gets to ±2% for over 95% cases with an additional calibration step. A metric-based assessment criterion that combines key performance metrics into a single detection event (DE) score derived from failure mode effects analysis (FMEA) principles is proposed with an example shown for the 2021 Range Rover Velar. The benefit being that it removes a more judgement-based, qualitative approach, aiding toolset selection and methods development gaps.
Beves, Christopher, Simmonds, Nicholas, Dalmau Graells, Eric
Comparison of Two Distinct Automatic Emergency Braking Control Strategies for Heavy Vehicles02-20-01-00049/2/2026
Research on automatic emergency braking (AEB) control algorithms for heavy vehicles is relatively limited. Compared with passenger cars, heavy vehicle AEB algorithms must accommodate both unloaded and fully loaded conditions, with the latter posing higher demands. This study compares two distinct AEB control strategies: the time-to-collision (TTC) algorithm and the professional driver fitted (PDF) algorithm. Using simulation analyses under three regulatory-recommended scenarios—stationary lead vehicle, slow-moving lead vehicle, and decelerating lead vehicle—the results indicate that the PDF-based control system better adapts to both unloaded and fully loaded conditions. It demonstrates significant improvements in braking performance and robustness compared to the TTC-based system. For an unloaded vehicle equipped with the PDF–AEB control system (5500 kg), the final gap to the lead vehicle is the longest (11.5 m) under the scenario of a stationary lead vehicle with an initial ego vehicle speed of 80 km/h and the shortest (3.1 m) under the scenario of a lead vehicle with an initial speed of 50 km/h braking at 0.4 g. For a fully loaded vehicle (12,500 kg), the corresponding final gaps to the lead vehicle are 11.2 m and 2.5 m, respectively.
Lai, Fei, Huang, Chaoqun
COVER ASSEMBLY, ELECTRICAL, FOR MS27212 TERMINAL BOARD ASSEMBLYAS18029F (Current)8/31/2026
AE-8C2 Terminating Devices and Tooling Committee
INSTALLING AND REMOVAL TOOLS, CONNECTOR ELECTRICAL CONTACT, TYPE I, CLASS 1, COMPOSITION CAS81969/17B (Current)8/31/2026
AE-8C2 Terminating Devices and Tooling Committee
INSTALLING AND REMOVAL TOOLS, CONNECTOR, ELECTRICAL CONTACT, TYPE III, CLASS 2, COMPOSITION AAS81969/12B (Current)8/31/2026
AE-8C2 Terminating Devices and Tooling Committee
Objective Quantification of Harmonic Impulsive Sounds and Interval Prediction of Sound Quality in Hybrid Vehicle Engines10-11-01-00038/28/2026
Steady advancement is observed in global research on eco-friendly and sustainable transportation. Rapid technological evolution of hybrid electric vehicles (HEVs) is documented. Lower overall noise output and more compact structures are achieved in HEV engines relative to conventional internal combustion engines. The perceptibility of harmonic impulsive sounds is significantly enhanced by these design characteristics. A close correlation is observed between these acoustic phenomena and negative human auditory perceptions. These events are treated as a core focus for HEV noise, vibration, and harshness optimization. Accurate quantification of harmonic impulsive sounds is not achieved by conventional objective indicators. A favorable balance between reliability and accuracy is not established by existing subjective prediction models. Practical engineering applications of these methods are severely restricted. A novel objective quantification method for harmonic impulsive sounds is proposed in this study. The method is established based on time–frequency masking theory and tonal strength. Bench tests in a semi-anechoic chamber and subjective evaluation experiments with standardized rating scales are performed for data collection. Collected sound signals are decomposed through an integrated approach of wavelet transform and variational mode decomposition. Targeted feature extraction is completed for harmonic impulsive sounds. A quantitative index incorporating human auditory temporal and frequency masking effects is developed. The proposed index exhibits a significantly stronger correlation with subjective evaluation results than traditional objective metrics, confirming its superior ability to reflect actual perceived sound quality. An interval prediction model for sound quality evaluation is established based on support vector machines and kernel density estimation. Traditional objective metrics and the proposed index are introduced as key input parameters. Effective and reliable prediction of HEV engine noise subjective satisfaction is achieved by the model.
Lin, Xu, Liang, Xingyu, Shi, Zhiyuan
Design, Simulation, and Experimental Evaluation of an R290-Based Dual Secondary Loop Thermal Management System for Electric Vehicles14-15-03-00188/28/2026
The transition toward low global warming potential (GWP) refrigerants, driven by increasingly stringent environmental regulations and carbon reduction targets, has imposed new requirements on thermal management systems (TMSs) for electric vehicles (EVs). These systems must ensure efficient operation across a wide range of ambient conditions while maintaining high energy efficiency and environmental compatibility. Among potential alternatives, R290 (propane) has emerged as a promising natural refrigerant due to its favorable thermophysical properties and low environmental impact. In this study, an R290-based dual secondary loop TMS is proposed and evaluated for wide-temperature-range EV applications. A one-dimensional system model was developed using Dymola and validated through experimental testing on a dedicated performance test bench. TMS performance was investigated under multiple steady-state operating conditions, including high-load cooling, battery fast charging, and low-temperature heating, and benchmarked against a conventional R1234yf-based direct TMS. The results demonstrate that the R290-based dual secondary loop system achieves improved performance compared to a conventional R1234yf direct system, with a coefficient of performance (COP) increase of 4.29% under high-load cooling conditions at 43°C and up to 27.27% under high-load heating conditions at −10°C. Furthermore, under extreme low-temperature conditions (−18°C), the system delivers a heating capacity of 7 kW with a COP of 1.8, demonstrating strong low-temperature adaptability without the need for auxiliary heating. The results confirm that the proposed R290-based dual secondary loop system provides significant advantages in energy efficiency and wide-temperature adaptability, offering a promising solution for next-generation EVTMSs.
Zhang, Yunpeng, Mohammed, Mustafa Mudassir, Gu, Yiliang, Zhou, Guoliang
Multi-Scale Investigation of Burn-Through Mechanisms during In-Service Welding of Pipeline Steel2026-99-04098/28/2026
The core challenge of in-service welding repair of oil and gas pipelines is the risk control of burn-through. Current research primarily focuses on macroscopic phenomena, lacking a systematic multi-scale analysis of burn-through mechanisms and their dynamic evolution. Existing criteria are primarily based on qualitative experience, and widely accepted quantitative safety assessment standards have yet to be established. Furthermore, insufficient understanding of multi-scale damage failure mechanisms and weak theoretical foundations have become bottlenecks in this field. This study targets X65 pipeline steel and combines in-service welding experiments with in-situ scanning electron microscope tensile tests to elucidate the formation mechanism of burn-through from a multi- scale perspective. The results show that during in-service welding, the remaining wall thickness of the pipeline continuously decreases with the welding process, ultimately resulting in burn-through holes. On one hand, the welding arc drives the expansion of the hole; on the other hand, the internal pressure of the medium further enlarges the hole, leading to the expulsion of water and rapid pressure loss in the pipeline. Notably, the fusion zone behind the maximum melt depth is subject to high temperatures, which reduces strength and degrades plasticity, exhibiting significant plastic strain, making it a high-risk area for burn-through instability. Before instability occurs, this region shows evident grain coalescence, with plastic deformation primarily occurring through dislocation slip; when the difficulty of activating slip systems increases, twinning deformation may be induced, and large twin grains rarely develop cracks. Strain concentration and crack initiation are more likely to occur between grains with significant orientation differences.
Wang, Bangyu, Qiao, YingJie, Li, Dong, Xu, ShiHang
Synergistic Effect of Matrix Porosity and Grouting Material Type on the Performance of Grouted Composite Pavement2026-99-04058/28/2026
The grouted composite pavement combines the advantages of flexibility and rigidity through the composite structure of organic-inorganic materials, but the optimisation of its performance is affected by the complexity of the matrix asphalt mixture void ratio and grouting material type. This study has revealed the influence of matrix asphalt mixture porosity and grouting material type on the grouting effect and road performance of grouted composite asphalt pavement. The results showed that the increase of matrix porosity could significantly improve the grouting rate and resistance to high-temperature rutting of the mortar, but the high porosity led to a decrease of low temperature cracking resistance of the materials. CA mortar enhanced the flexible deformation capacity by optimising the interfacial bond, and its low-temperature cracking resistance was better than that of ordinary cement mortar, but the grouting efficiency and high-temperature performance were slightly lower. In addition, ordinary cement mortar demonstrated better performance regarding high-temperature stability and resistance to water damage.
He, Mu, Wang, Yan, Ye, Ming, Yu, Chao, Ye, Xiao
Vinylene-Linked Covalent Organic Frameworks as Superior Photocatalysts for Hydrogen Evolution over Imine-Linked Counterparts2026-99-04148/28/2026
The scheme of photocatalysis of water, a way of hydrogen generation as a clean, high-efficiency fuel source for aircraft and long-range transport systems has received considerable interest. The development of the covalent organic framework (COF) - derived materials for hydrogen evolution reaction (HER) has since become a research highlight. Compared to traditional methods, photocatalytic hydrogen evolution systems based on COFs can provide ways of generating hydrogen gas without depending upon noble metal catalysts, thereby enhancing the sustainability and prospects of this technology for future aerospace energy applications.In this work, two covalent organic frameworks (COFs) with distinct linkages—a vinylene-linked COF A (via Knoevenagel condensation) and an imine-linked COF B (via Schiff-base reaction)—were designed and synthesized to compare their performance in the photocatalystic hydrogen evolution reaction (HER). Structural and electrochemical characterizations confirmed that, despite lower crystallinity and specific surface area due to pore blockage, COF A exhibited a suitable band structure for photocatalysis and achieved an HER rate of 56 μmol h^–1 g^–1 under simulated sunlight. In contrast, COF B was ineffective. This study experimentally validates the superior photocatalytic potential of vinylene-linked COFs over imine-linked counterparts for HER, highlighting their potential as non-noble-metal catalysts for aerospace and transport-oriented fuel generation.
Cao, Yijie, Luo, Xin
Effect of Copper Valence and Content in Copper Red Glaze on Its Color Appearance2026-99-04208/28/2026
Copper red glazes have received considerable attention due to their perfect decorative effects and vivid coloration. This paper selected four different formula copper red glazes with different colors of bright red, violet blue, dark red, and gray blue as the samples. Based on the analysis of the colorimeter, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscope (SEM), a possible coloration mechanism was proposed to explain the variation of glaze colors. The results indicated that the glaze layers were mainly composed of amorphous phases with few quartz diffraction peaks and mainly presented a granulous structure and phase separation. Increasing the content of CaO could cause color changes of the glaze due to the high ionic potential of calcium ions, which could form a unique feature in the glaze melt. In addition, a small amount of calcium phosphate could greatly change the color of the glaze. The phase separation structure of the blue samples was more obvious than that of the red samples, with a phase separation size of less than 100 nm. The formation of droplet phase separation structure in the glaze could lead to Rayleigh scattering and Mie scattering, which made the color of copper red glazes blue and opacified. Increasing the content of Cu0 and decreasing Cu+ could weaken the structural color, which contributes to a* value of the glaze changing from 26.93 to 22.93. At the same content of Cu0, the higher the ratio of Cu+ /Cu2+ is, the less a* value of the glaze is. Finally, the existence of CuSiO3 in the glaze could also make the blue color.
Ding, Erbao, Yang, Mengli, Liu, Nannan, Li, Yabo, Zheng, Ruimiao, Xu, Yan
Synthesis and Performance Study of a High-Workability Polycarboxylate Superplasticizer2026-99-04038/28/2026
This study used hexacarbon polyether (EPEG), acrylic acid (AA), polyethylene glycol maleate (MAPG), and vinyl acetate (VA) as the main raw materials to synthesize a highly workable polycarboxylate superplasticizer (CE-02) under the action of an initiator. The structure of the target product was characterized by FTIR and GPC. Tests showed that under conditions of low water dosage (150 kg), low cementitious material content (220 kg of cement), and poor aggregate gradation, the concrete mixed with CE-02 exhibited an initial slump flow increase of 25 mm, a bleeding rate of 0.6%, no stone exposure, and excellent workability.
Chen, Wenhong, Deng, Lei, Jiang, Yu, Zhang, Bo
Numerical and Experimental Investigation of the Impact of Close-Range Construction of Large-Section Tunnels on Existing Subway2026-99-04258/28/2026
Large-section tunnel construction using the mining method can significantly affect the operational safety of existing metro lines and ground stability, while their non-uniform settlement remains challenging to monitor comprehensively. In this study, the post-station section of a metro project in Chengdu was investigated to elucidate the vertical displacement and ground settlement behavior induced by a large-section tunnel undercrossing an existing metro line. A displacement reconstruction method integrating sparse-point monitoring with a radial basis function neural network (RBFNN) was developed to fit the full-field settlement distribution of both the existing line and the ground surface. A finite element model incorporating the existing shield tunnels, station structures, and the newly constructed mined tunnel was established, and the construction process was simulated. The numerical results indicated maximum settlements of 4.42 mm for the existing line and 4.37 mm for the ground surface, with fitting errors below 5.8% and 6.1%, respectively. Physical model tests further validated the approach, yielding maximum settlements of 0.86 mm and 1.01 mm for the existing line and ground surface, respectively, and an average fitting error below 3.5%. Both numerical and experimental findings confirmed that the induced displacements were within a controllable range and that the surrounding strata remained stable. The proposed method enables accurate and intuitive reconstruction of displacement distribution during under-crossing tunnel construction, reducing the number of required monitoring points while maintaining high fitting accuracy.
Wang, Rui, Chen, Jian, Cheng, Tao, Du, Lin, Li, Ruixiao
Simulation of Gas Diffusion in Nanoscale Microchannels at the Parallel Seam-Weld Interface2026-99-04198/28/2026
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, Xiangyang, Gong, Yubing, Zheng, Xianling
A Study on the Dynamic Characteristics of Long-Span Single Conductors Using Meshfree Methods2026-99-04248/28/2026
The free vibration characteristics of long-span transmission conductors form the fundamental basis for vibration control design, as their natural frequencies and mode shapes directly affect line safety and the selection of vibration suppression devices. In this study, the three-dimensional linear free vibration governing equations were derived through functional integration of the kinetic and potential energies by using Hamilton’s variational principle. Compared with the conventional integral transform method, an improved meshfree discretization strategy is proposed: the shape functions are constructed using the moving least squares (MLS) method, while the boundary conditions are treated with a fully transformed approach, thereby converting the partial differential equations into ordinary differential equations. Subsequently, a corresponding eigenvalue problem is solved to calculate the first few frequencies of the system, and the effect of conductor natural parameters on these frequencies for the transmission conductor is investigated. The results indicate that the natural frequency decreases when the conductor length becomes larger, and the rate of decrease becomes more gradual as the length increases; it decreases with increasing cross-sectional diameter; it decreases linearly with increasing material density; and it increases linearly with increasing elastic modulus. These findings demonstrate that conductor length, cross-sectional diameter, material density, and elastic modulus all have significant effects on the natural frequency. Among them, length and diameter affect the frequency by altering the conductor’s inertia and structural characteristics, whereas density and elastic modulus govern the frequency from the perspectives of inertia and stiffness, respectively.
Li, Chen, Cheng, Yongfeng, Li, Danyu, Qiu, Gang
Improvement of Cyclic Stability of P2-Na 0.67 Co 0.67 Mn 0.33 O 2 Cathode Material by Al 2 O 3 Coating2026-99-04228/28/2026
P2-type layered oxides are good cathode materials in high-performance sodium-ion batteries since they have desirable two-dimensional ion migration pathways. However, their instability at interfaces and their attenuation as cycles persist also remain a significant challenge. To increase their electrochemical stability, surface coating is also a good plan, but the balance between the coating and ionic conductivity is one of the key challenges. This study constructed an immensely thin layer of alumina (Al2O3) coating, and the influence of the amount of the coating (0.3-1.2 wt percent) on the working of the material was methodically examined. Electrochemical analysis showed that the lowest levels of Al2O3 (0.3 wt) provide the greatest improvement in performance. The optimized sample showed a retention capacity of 96.35 after 100 cycles of operation at 1C, significantly higher compared with samples that had increased coating contents. An analysis of cyclic voltammetry and impedance spectroscopy was subsequently done to corroborate the presence of a 0.3 wt% coating, which infected the electrode-electrolyte interface by inhibiting side reactions but minimally obstructing sodium-ion transport and thus promoting reaction reversibility and improved interfacial kinetics. These results highlight the importance of a less-is-more rule when it comes to surface coating and provide a novel understanding of how long-life sodium-ion battery cathodes can be designed by carefully engineered interfaces.
Hu, Chao, Peng, Rui, Zhou, Yu, Zhou, Dengmei, Tian, Liangliang
Development of Remote Cab Controller for Construction Machinery14-15-03-00178/27/2026
This article focuses on the research and development of a remote cab controller for pure electric loaders, aiming to address the threats posed by traditional loaders operating in harsh and hazardous environments to drivers’ health and safety. First, the functional requirements of the controller were analyzed, based on which the hardware design with a multicore microprocessor as the core was completed, featuring functions such as signal acquisition, controller area network (CAN) communication, and H-bridge driving. On this basis, a control algorithm framework for remote driving was developed, including modules for signal input, analysis and processing, and signal output. Detailed control strategies were formulated for key components: For the pedal sensor, algorithms for opening degree calculation, automatic zero-position calibration, and dual-signal redundant fault diagnosis were proposed; for the steering module, precise angle calculation and force feedback feel simulation were achieved; and for the electric control handle, a hysteresis control algorithm was developed to suppress shocks caused by overly fast operations. In addition, a hierarchical fault diagnosis mechanism was established to ensure system safety. To verify the controller performance, a complete remote driving system was built. Field test results show that the system exhibits good signal following and control responsiveness in terms of traveling and working functions. Efficiency tests indicate that the remote driving efficiency can reach 80% of that of in-person operation under short-term test conditions, demonstrating the technical feasibility and control effectiveness of the developed controller. While the prototype exhibits promising performance for pilot deployment, long-term reliability metrics such as mean time between failures (MTBF) remain to be validated through extended field operation.
Lu, Yueqi, Ji, Shaobo, Yu, Qiuye, Li, Meng, Xu, Haozhi, An, Meng
Study of Port Fuel Injection Engine Cold Start Unburned Hydrocarbons Reduction Using Computational Fluid Dynamics with a Reduced Iso-Octane Mechanism Considering Various Isomers and Thermal Decompositions03-19-04-00218/27/2026
A modeling study was performed to find solutions to reduce the unburned hydrocarbons during cold start of a PFI (port fuel injection) SI (spark ignition) engine. Through modeling, the root cause for the high unburned hydrocarbons of the baseline engine during cold start was found. The slow combustion, which is due to the high amount of exhaust gas flowing back into the intake port and then becoming trapped inside the cylinder, is the root cause. A new valve lift, which can reduce the internal residual by 26%, was designed. Along with a fuel amount decrease of 35%, the UHC (unburned hydrocarbons) before the three-way catalyst can be reduced by 40%. The exhaust temperature using the new valve lift design increases by 400°C, which improves the performance of the three-way catalyst for further reducing UHC. In addition to the adoption of the new valve lift, an active SAI (secondary air injection) strategy was also investigated. Modeling results show that SAI can promote secondary combustion in the exhaust pipes to increase exhaust temperature and thus is beneficial for further oxidizing unburned hydrocarbons. The amount of active SAI mass flow rate should be controlled to less than 25% of the intake air flow rate to avoid the cooling effect dominating over the oxidation process. The duration of SAI should be from EVO (exhaust valve opening) to IVO (intake valve opening). For combustion modeling, a newly reduced iso-octane chemical kinetic mechanism was developed using carbon flux analysis to extract major reaction pathways for a wide range of practical engine temperature conditions. In the new reduced mechanism, a skeletal sub-mechanism for species starting from iso-octane to C4 is coupled with a recently updated H2/O2/CO/C1–C4 detailed sub-mechanism. Including a reduced NOx (oxides of nitrogen) sub-mechanism, the final mechanism has 681 species and 3332 reactions. Before the new reduced iso-octane mechanism was used, it had been validated with available experimental data of ignition delay times, laminar flame speeds, and important species profiles in the literature. Both the investigation of PFI engine unburned hydrocarbons reduction under cold start operating conditions and the development of a reduced chemical mechanism are the objectives of this work.
Guo, Dongshao, Zhang, Licheng, Yang, Shiyou, Bourg, Cyrus, Sun, Yong, Abidin, Zainal, Lin, Shujun
AVSC Best Practice for ADS Remote Assistance Training and Human FactorsAVSC-I-07-20268/25/2026
AVSC Best Practice for ADS Remote Assistance Training and Human Factors is intended to support the development of processes regarding automated driving system-dedicated vehicle (ADS-DV) remote assistant training, qualification, assessment, and performance-related human factors. It provides information to standardize communication about remote assistance (RA) programs to stakeholders to increase public trust in the operation of ADS-DVs by providing guidance on training for remote assistants.
Automated Vehicle Safety Consortium
CRIMPING TOOL AND ACCESSORIES, 18 VDC BATTERY ELECTRIC, PORTABLE HYDRAULIC, WIRE SIZE 8 TO 00 UN-INSULATED, AND SIZE 8 THRU 2 INSULATED CRIMP BARRELSAS5259/8A (Current)8/24/2026
AE-8C2 Terminating Devices and Tooling Committee
Test Guidelines for Assessment of Electrical Insulation Material Aging in a High Voltage SystemARP7375 (Current)8/24/2026
To provide test guidelines, recommendations, and referenced standards for insulation materials in a high energy system especially at high voltages (AC, DC, and PWM) and at operational altitudes, for the purpose of defining/measuring the effects of insulation aging. This document is a part of a family of documents related to the impact of ageing on insulating materials devoted to aviation applications. Aging mechanisms, and the markers to monitor them, have been defined in AIR7374. For sake of brevity, the main conclusions are used here. ARP7375 focuses on the ways to measure these markers on representative samples (either coupons or electrical insulation systems) for aerospace applications.
AE-11 Aging Models for Electrical Insulation in Hi-Enrgy Sys
Resilient Trajectory Tracking Static Output-Feedback Control for Automated Vehicles under Denial-of-Service Attacks10-11-01-00028/24/2026
The safety and reliability of autonomous vehicles are critically linked to network communication quality. Consequently, threats such as Denial-of-Service attacks pose significant risks by disrupting communication between essential components and jeopardizing driving safety. This article presents a robust trajectory tracking control method resilient to such attacks. Utilizing a Linear Parameter–Varying control framework, the method effectively addresses time-varying vehicle speeds and incorporates a norm-bounded strategy to manage tire behavior uncertainties. By employing a Static Output-Feedback scheme, it avoids the need of costly sensors while maintaining a straightforward control structure suitable for real-time implementation. Using Lyapunov’s method, we analyze the system stability under attack conditions, ensuring the controller remains robust against disturbances. The design of the resilient controller is formulated as a convex optimization problem with Linear Matrix Inequalities constraints. The effectiveness of the proposed controller is validated through co-simulation in MATLAB/CarSim®, where it outperforms several state-of-the-art controllers across different driving scenarios, maintaining consistent tracking performance despite varying attack severity levels.
Meléndez-Useros, Miguel, Viadero-Monasterio, Fernando, Nguyen, Anh-Tu, López-Boada, María Jesús
WIRE, ELECTRICAL, FLUOROPOLYMER-INSULATED CROSSLINKED MODIFIED ETFE, LOW FLUORIDE, NORMAL WEIGHT, 80 MICROINCH SILVER-COATED COPPER 200 °C, 600 VOLT, ROHSAS22759/50C (Current)8/18/2026
AE-8D Wire and Cable Committee
WIRE, ELECTRICAL, FLUOROPOLYMER-INSULATED, CROSSLINKED MODIFIED ETFE, LOW FLUORIDE, LIGHTWEIGHT, 80 MICROINCH SILVER-COATED HIGH-STRENGTH COPPER ALLOY, 200 °C, 600 VOLT, ROHSAS22759/47C (Current)8/18/2026
AE-8D Wire and Cable Committee
Items per page:
1 – 50 of 59496