Browse Topic: Data exchange

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Scene-Level Multi-View Instance Consistency Using Multi-Feature Vision Fusion for Synthetic Ground Vehicle Environments2026-01-75029/22/2026
Maintaining consistent object identities across multiple camera viewpoints is a critical challenge in synthetic perception environments used for autonomous ground vehicle evaluation. This paper presents a scene-level multi-view instance consistency framework that integrates OpenUSD scene composition, Omniverse Replicator synthetic-data generation, and a multi-feature vision fusion pipeline. The proposed approach combines semantic embeddings from CLIP, patch-level descriptors from DINOv2, geometric correspondences from LoFTR, mask-derived shape invariants using Hu moments, and relative-position priors to associate object instances across views, including visually identical objects. A compact composite scoring function fuses these complementary cues to achieve robust cross-view identity assignment while preserving OpenUSD asset modularity through grouped-prim support. Synthetic experiments across 120 multi-camera scenes demonstrate improved Top-1 Match Accuracy and Identity Consistency Rate, with reduced ID-switch occurrences compared to single-cue baselines. The framework supports scalable, repeatable, and traceable digital engineering workflows for defense-oriented perception evaluation.
Bhattacharya, Sambit, Nakamoto, Kyle
Distributed Intelligence at the Tactical Edge: Enabling Contested Logistics in Degraded Networks2026-01-75589/22/2026
Contested logistics environments expose the limitations of both legacy fragmented systems and emerging Next Generation Command and Control architectures that assume persistent connectivity. In degraded or denied conditions, sustainment operations face latency, bandwidth constraints, and reduced decision velocity. Expanded decision support tools further increase reliance on timely, relevant data exchange. This paper argues that contested logistics requires distributed, mission-aware intelligence at the tactical edge. Low-power onboard compute enables real-time inference, adaptive data conditioning, and connectivity-aware transmission across Radio-Frequency and non-RF pathways. By selectively elevating critical information based on mission context and network state, edge-intelligent architectures improve survivability, bandwidth efficiency, and sustainment effectiveness in degraded networks.
Baumann, Edward, Pardee, Shawn
Computational Electro-Thermal and Degradation Modeling Framework for Lithium-Ion Batteries in Electric Vehicles2026-24-00119/21/2026
This paper presents an integrated computational framework that couples electro-thermal and degradation dynamics for lithium-ion batteries used in electric vehicles (EVs). The model is implemented using Python. At the cell level, the model describes charge and discharge behavior, state of charge (SOC), terminal voltage, internal resistance losses, and heat generation. An energy balance equation is used to estimate temperature variation during operation. Temperature-dependent resistance and capacity are included to represent nonlinear battery behavior under different load conditions. At the system level, feedback relationships between SOC, temperature, state of health (SOH), and degradation rate are modeled using system dynamics. Battery aging is represented through mathematical functions that relate capacity loss to temperature and usage cycles. This allows simulation of long-term performance under different driving scenarios. The model enables parametric and sensitivity analyses to evaluate the effects of discharge rate, ambient temperature, and degradation parameters. Results show the strong interaction between thermal behavior and battery aging. Model validation against experimental data is not performed in this study and remains an important direction for future research. The current work focuses on the derivation and parametric analysis of the modelling framework. The proposed framework provides a clear, low-cost, and scalable computational approach for EV battery analysis, design studies, and engineering education.
Gutierrez, Marcos, Taco, Diana
Further Investigation of the Variables Affecting Brake Squeal: Dual-Piston and Single-Piston Calipers with NAO Pads2026-01-08259/14/2026
An earlier publication reported that brake squeal occurrence increases with increasing (inboard/outboard) pads wear rate difference in the case of a front dual-piston (twin-piston) caliper for a GVW vehicle of 2,510 kg fitted with Lowmet pads of straight chamfers and diamond chamfers. The current investigation was undertaken to find out if a front dual-piston caliper for a heavier vehicle (GVW 3,200 kg) fitted with NAO pads of straight chamfers, and a lighter single-piston caliper (GVW 2,100 kg) fitted with NAO pads of straight chamfers behave the same or not, using the SAE J2521 and Los Angeles City Traffic simulation procedures. In all cases, brake squeal is found to increase with increasing (inboard/outboard) pads wear rate differences (wear differentials); increasing pad radial taper is associated with increasing (I/O) pads wear differential; pad tangential taper lowers the (I/O) pads wear differential. Increasing friction coefficients do not relate to increasing squeal occurrences. To minimize brake squeal occurrence, caliper should be designed to minimize (I/O) pads wear differential.
Sriwiboon, Meechai, Rhee, Seong Kwan, Sukultanasorn, Jittrathep, Khathinhorm, Nicha, Kunthong, Jitpanu
Predicting Wear of NAO Brake Pad Using Scaled-Down FMVSS 135 Testing and Machine Learning2026-01-08089/14/2026
Brake pad wear is a major and growing source of non-exhaust particulate emissions, projected to reach 1.3 million tons annually by 2030 and contributing up to roughly 55% by mass of non-exhaust traffic-related PM10 in urban environments, underscoring the need for improved durability and material optimization. This study investigates a three-stage eXtreme Gradient Boosting (XGBoost) ensemble paired with a residual Fully Connected Neural Network (FCNN) corrector to predict brake pad wear rate and support formulation optimization. Experiments used a simplified FMVSS 135 protocol on a Universal Mechanical Tester (UMT) simulating realistic braking across eight friction regimes. Wear rate was the sole machine-learning prediction target, while coefficient of friction (CoF) was retained as an input feature rather than a target. Despite a limited but high-quality 280-cycle dataset, regime-aware stratified splitting, sample reweighting, and hyperparameter optimization enabled robust generalization. The three-stage XGBoost ensemble with residual FCNN correction achieved a global held-out test R2 of 0.976 for wear rate prediction. A Taguchi L8 design of experiments defined the brake pad compositions, reducing experimental time and material consumption compared to conventional approaches. The framework demonstrated strong agreement between measurements and predictions for the dominant low-severity regime, while per-regime analysis identified the high-severity minority regimes as the priority for additional data collection, since within-regime R2 remains negative for every regime given current sample sizes. A sequence-aware mean absolute scaled error (MASE) analysis further shows that, despite the high global R2, none of the four pipeline stages currently outperforms a naive one-cycle persistence forecast on absolute error, a distinction reported here for transparency. The scalable architecture enables straightforward integration of additional material and process parameters, supporting iterative brake formulation development in industrial settings and, by reducing empirical testing requirements, sustainable brake material development with reduced replacement frequency and associated emissions.
Katakam, Abhishek, Eslamiat, Hossein, Kancharla, Sai Krishna, Filip, Peter
Research on the Stability of Three-Axis Vehicles with Coordinated Steering under High-Speed Low-Adhesion Conditions2026-99-11369/11/2026
Three-axle vehicles are widely used in engineering, transportation, and other heavy-duty applications, but they are prone to lateral instability at high speeds or on low-adhesion road conditions, which severely degrades handling stability. To enhance their dynamic performance under extreme operating conditions, this paper proposes a direct yaw-moment control (DYC) strategy based on an incremental linear quadratic regulator (ILQR) for a distributed-drive three-axle vehicle equipped with active front-wheel steering (AFS) and differential drive assist steering (DDAS), thereby improving the accuracy and responsiveness of lateral stability control. Furthermore, to mitigate the mutual coupling and interference among multiple control subsystems, a coordinated steering strategy based on phase-plane analysis is proposed to achieve effective integration and dynamic coordination of AFS, DDAS, and DYC. Co-simulation studies conducted in Matlab/Simulink and TruckSim reveal that the proposed coordinated steering strategy substantially diminishes the peak yaw rate and vehicle sideslip angle across diverse driving conditions, thereby considerably enhancing the lateral stability of the three-axle vehicle during extreme maneuvers.
Hu, Jiadong, Wang, Tie
Analysis of Traffic Capacity at the Intersection of Xiyou Road and Qianshan Road in Hefei City2026-99-15519/11/2026
With the advancement of urbanization and the popularization of automobiles, the traffic load on urban roads is becoming increasingly heavy, resulting in many traffic problems. Road intersections serve as crucial linchpins in the urban transportation grid, wielding considerable influence over the overall traffic capacity of a city’s road network. Enhancing intersection efficiency and cutting down on delays stand at the heart of tackling urban congestion challenges. This study zeroes in on the crossroads where Xiyou Road intersects with Qianshan Road in Hefei City. Employing hands-on observation and photographic documentation, the research examines traffic flow and signal configurations during the peak demand period (7:30-8:30). The analysis evaluates traffic capacity and utilization rates for through, left-turn, and right-turn lanes at this intersection. Findings reveal that the right-turn lane at the southern entrance and the left-turn lanes at both northern and eastern entries show relatively low saturation levels, while the saturation of other lanes is greater than or close to 1. Therefore, this intersection does not have sufficient capacity. The actual traffic operation at the intersection, particularly during peak traffic times, is analyzed to identify the reasons for congestion Finally, improvement plans for optimizing traffic organization at intersections are proposed, such as optimizing signal timing schemes and transforming traffic channelization. Simulation analysis using VISSIM shows a 9.34% reduction in total intersection parking time, a 34.26% decrease in average queue length, and an 8.12% reduction in average vehicle delay. These results provide a reference for future optimization work, including intersection signal timing and channelization.
Wang, Yanmei, Wang, Chen, Fu, Ziyue, Meng, Xianglong
Effect Evaluation of Emergency Barrier-free Blocking Methods in Highway Tunnels Based on Visual/Driving Behavior2026-99-15319/11/2026
To address the lack of safe and effective on-site vehicle blocking and control methods in the event of fires or other emergencies in extra-long tunnels — which can significantly reduce traffic safety risks and prevent secondary accidents — this study proposes a novel barrier-free light–smoke curtain interception method. The method integrates conventional traffic safety warning facilities (gantry-mounted variable message signs and audio–visual alarms) with two light–smoke curtain interception images to form a composite early-warning and interception system. Driving simulation experiments were conducted to comprehensively evaluate its warning effectiveness, interception performance, and operational safety in comparison with methods employing only traditional warning facilities or light curtain images. Furthermore, field drills were performed to validate its real-world applicability and interception effectiveness under both daytime and nighttime conditions. The main findings are as follows: 1) The fixation ratio and interception success rate associated with the proposed method were significantly higher than those of the other two methods, demonstrating enhanced visual attention and superior warning and interception performance. 2) The maximum deceleration observed with the proposed method was lower than that of the light curtain–only method and did not trigger emergency braking, thereby indicating high operational stability and driver comfort. 3) In field drills, after activation of the interception equipment, only one and two vehicles entered the tunnel under daytime and nighttime conditions, respectively, and full control of on-site vehicles was achieved within two minutes without any traffic accidents, verifying the system’s rapid response and effective safety assurance.
Shi, Mingjun, Li, Shicao, Wang, Haohuan, He, Qifei, Che, Zhengzhang, Li, Yanbo
Real-time Vehicle Speed Detection Based on YOLOv11 and DeepSORT2026-99-15959/11/2026
The technology of real-time and effective vehicle speed detection is considered a key technology to improve traffic monitoring efficiency and traffic safety management grade. To address the limitations of traditional speed detection schemes—including reliance on dedicated hardware, poor environmental adaptability, and high construction and maintenance costs—this paper proposes a r10eal-time vehicle speed detection system based on YOLOv11 and the DeepSORT algorithm. The proposed system uses the YOLOv11 target detection algorithm as its primary model. DeepSORT multi-target tracking technology is integrated to enhance tracking performance. Speed measurement is implemented using a virtual detection line. This approach enables accurate vehicle detection, continuous tracking, and real-time speed measurement within video frames. Through the experiments, the result shows that the improved YOLOv11n model reaches mAP@0.5 of 0.982 and a recall rate of 0.956 in the test set, higher than the YOLOv8n and YOLOv5s models. The speed detection error can be restricted to 3 km/h, satisfying the real-time detection need. There is no need for road surface modification, and the detection system has a flexible layout, providing a dynamic basis for traffic law enforcement and traffic data support for road construction and traffic control optimization.
Jin, Guowei, Ma, Wenlong, Jiang, Dali, Li, Nan
Study on Low-Velocity Impact Damage of Glass Fiber Reinforced Composite Pipeline2026-99-14169/11/2026
Through low-velocity impact testing, the effects of punch shape (conical, hemispherical, and cylindrical) and impact energy (5, 10, and 15 J) on damage characteristics in glass fiber composite pipes were investigated. Ultrasonic A-scan inspection was employed to detect internal delamination damage at the impact points within the composite pipes. Test results indicate that the contact area between the punch and the pipe is a key factor influencing the severity of pipe damage. A smaller contact area results in a higher energy absorption rate, greater punch displacement, larger area under the load-displacement curve, and longer contact time, leading to more severe damage characteristics. When the conical punch delivered 15 J of impact energy, the energy absorption rate of the glass fiber composite pipe reached 91.6%, exhibiting multiple damage characteristics, including pitting, penetration, and cross-shaped cracks. As impact energy increases, the area of internal delamination damage caused by the three punch shapes exhibits near-linear growth. The conical punch induces severe damage characteristics in the thickness direction but results in the smallest delamination area. Blunt-shaped punches (hemispherical and cylindrical) disperse impact energy over a wider region, leading to increased delamination damage area.
Wang, Xuan, Cao, Yanzhen
Research on Torque Allocation Control of Multi-Articulated Vehicle2026-99-11239/11/2026
The multi-articulated vehicle uses distributed drive mode. Due to its large degree of freedom of movement and the large number of driving shafts, different torque distribution methods affect the operational stability of the vehicle, how to coordinate and distribute the torque of each driving motor has become an urgent problem to be solved. To improve drive stability of the multi-articulated vehicles, propose a layered torque allocation control strategy. The upper-layer sliding mode controller determines the required additional yaw moments of each car body based on the linear reference model, the controller is characterized by swift response and a strong ability to resist interference. The lower-level allocation module comprehensively considers the torque output limitations of the electric hub motors, the prevailing road adhesion state, and the corrective yaw moment constraints given by the upper layer, and constructs an optimization objective function centered on the uniformity and stability of tire load. The optimal distribution of driving forces for each wheel is completed by solving this function dynamically. To validate the strategy's effectiveness, a vehicle dynamics model is built in the multi-body dynamics software ADAMS/View. Using a joint simulation framework integrating ADAMS/View and MATLAB®/Simulink, the effect of the layered control strategy is evaluated in comparative simulation with uncontrolled situation under U-turn and single lane change conditions. The simulation outcomes demonstrate that, compared to uncontrolled situation, the yaw rate deviation of each car body under the torque layered control are significantly reduced, and the adhesion utilization rate of tire is also effectively controlled, thereby the driving stability is improved.
An, Guanbo, Zhang, Liwei
Research on the Synergetic Coupling Evaluation between the Yangtze River Delta Airport Cluster and the Regional Economy2026-99-15429/11/2026
To explore the coordinated development status between the Yangtze River Delta (YRD) airport cluster and the regional economy, this study takes the period from 2015 to 2023 as the research timeframe. It constructs an evaluation index system covering two dimensions: regional economy (including scale, structure, and benefit) and airport cluster development (including transportation scale, operation efficiency, among others). The Gini coefficient method and Pearson correlation coefficient method are used to screen indicators, while the entropy weight-standard deviation combined weighting method is adopted to calculate weights. Additionally, the coupling coordination model and geographical detector are integrated for in-depth analysis. The results show that the coupling coordination degree of the Yangtze River Delta region as a whole and its internal provinces and cities has rapidly recovered from the severe imbalance during the COVID-19 pandemic, featuring an inherent characteristic of “gradient catch-up and coordinated upgrading”. Factors such as the growth rate of passenger throughput and local fiscal general budget revenue have been identified as core influencing factors, and the interaction among these factors presents trends of two-factor enhancement and nonlinear enhancement. This study provides a theoretical basis and practical reference for promoting the integrated and coordinated development of the Yangtze River Delta airport cluster and the regional economy.
You, Zihao, Li, Yanwei
A Three-Dimensional Safety Domain Method for LNG Vessels in Ports Based on Human Factors and Speed Characteristics2026-99-15239/11/2026
To accurately assess the navigation safety status of LNG vessels in port waters and balance safety control with waterway capacity efficiency, this study constructs a 3D dynamic safety domain model for port LNG vessels, integrating human–ship–environment multi-factors. The model introduces the Weibull function to quantify the impact of drivers’ knowledge, skills, and physiological-psychological states on safety boundaries, combines a ship motion mathematical model to establish a 2D safety domain boundary equation, and incorporates hull subsidence to build a vertical dimension, forming a complete 3D model. Longitudinally, the safety distance is calculated using the car-following braking theory, while laterally, boundaries are determined by controlling the ratio of inter-vessel interference force to navigation resistance. Through static scenario analysis and dynamic simulation verification, results show that the safety domain scale is dominated by ship speed and environmental conditions, and its shape tends to shrink as the driver’s state improves, making it more suitable for actual port scenarios than traditional models. Verified with a specific LNG hub port as a case, the safety distance calculated by the model is significantly reduced compared with current specifications, while the delay impact rate and average delay time on other vessels are decreased. The research results establish a quantifiable framework for dynamic safety assessment, providing maritime administrations and on-board pilots with a scientifically-grounded tool to determine real-time safe navigation boundaries in complex port environments, balancing safety control with operational efficiency.
Wang, Yangang, Jia, Changsheng, Zhu, Jinshan
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
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
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
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
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
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
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
Evaluating the Applicability of Advanced Physical Vapor Deposition Coatings through Characterization and Dry Machining05-19-04-00318/18/2026
This study investigates the characterization and dry machining performance of advanced physical vapor deposition (PVD) aluminum titanium nitride (AlTiN) and aluminum chromium titanium nitride (AlCrTiN) coatings deposited using three techniques: cathodic arc evaporation (CAE), high-power impulse magnetron sputtering (HiPIMS), and scalable pulse power plasma (S3p). The coatings were evaluated for thickness, microstructure, surface roughness, coefficient of friction (CoF), adhesion strength, and microhardness. Among the tested coatings, the S3p-deposited AlCrTiN showed the best performance, exhibiting the highest microhardness (40 GPa), the strongest adhesion (108 N), and the lowest CoF (0.25), along with a defect-free microstructure. Under the selected dry turning condition of 150 m/min cutting speed, 0.15 mm/rev feed rate, and 0.7 mm depth of cut, the S3p-deposited AlCrTiN coating achieved a maximum tool life of 10,800 mm, nearly three times higher than the CAE-deposited AlTiN coating. In contrast, CAE coatings showed comparatively lower hardness and weaker adhesion, with minimum values of 25 GPa and 68 N for C1, along with higher CoF values of 0.58–0.60. Furthermore, AlCrTiN coatings produced by HiPIMS and S3p provided 20–30% longer tool life than AlTiN coatings under identical cutting conditions, highlighting the importance of deposition technique.
Sonawane, Gaurav Dinkar
Numerical Simulation Study on Fire Prevention in Aero-Engine Fuel Tube2026-99-03038/14/2026
Transient gas-liquid two-phase flow in aero-engine fuel pipelines was examined using numerical simulations, focusing on the influence of flow rate on phase change behavior. Under low-flow conditions, phase change occurred repeatedly near the pipe wall, where vapor layers formed and collapsed in an intermittent manner. These processes introduced noticeable unsteadiness in the local mass flow and pressure fields. When the flow rate was increased, vapor generation was largely confined to a narrow region adjacent to the wall, and the overall flow exhibited a more stable character. The results suggest that flow-rate-dependent phase change plays an important role in determining the stability of fuel transport and should be considered in the fire safety assessment of aircraft fuel systems.
Wu, Bin, Xin, Bo, Zeng, Tai, Su, Zhengliang
Design of Adaptive Overtorsion Sliding Mode Observer Based on Logarithmic Gain Law and Estimation of Satellite Disturbance Torque2026-99-03158/14/2026
The vigorous rate of new spacecraft being launched has made the accurate estimation of in-orbit environmental disturbances torques paramount to reducing attitude control performance corrosion. Leveraging telemetry from an asset in low-earth-orbit, we present a novel Adaptive Super-Twisting Sliding-Mode Observer, which interlinks three techniques heretofore decoupled: 1) saturation-constrained angular-acceleration adaptation; 2) Kalman-filter preconditioning of angular velocity; and 3) state-weighted logarithmic gain with dual leakage. Denoising of raw Euler angle sequences and detection of quasi-steady epochs are achieved with a customized Kalman update, while an adaptive band-pass stage isolates the torque-related acceleration signature. Casting these filtered data into the super-twisting form, we update the log gain on-the-fly, and twin leakage terms remove excess energy with accompanying chatter rejection—without compromising bandwidth. Head-to-head telemetry tests show a positive margin headroom on noise attenuation that has to be compared with the power-gain type counterpart and that increases with the signal roughness, thereby validating the fact that this technique refines environment torque estimates and hence strengthens robustness design envelopes in next-generation attitude-control systems.
Yin, Xu, Deng, Yuhui, Chi, Dongxiang
Research on Optimizing Mars Atmospheric Capture Approach Trajectories Based on the Adaptive Differential Evolution Algorithm2026-99-03078/14/2026
To strictly balance orbital insertion precision with engineering constraints during Mars aerocapture, we present an angle-of-attack (AoA) trajectory optimization framework based on adaptive differential evolution. First, a three-degree-of-freedom flight dynamics model was established utilizing the Mars-GRAM 2024 atmospheric standard. Subsequently, we formulated a penalty function centered on apoapsis altitude deviation to enable constraint-oriented dynamic optimization. Within this framework, we introduced an adaptive, direction-guided mutation strategy that integrates global optimal individuals with elite solutions. Furthermore, a parameter update mechanism driven by mutation success rates was developed to significantly enhance algorithmic robustness and computational efficiency. The AoA command sequence for the capture phase was parameterized using a piecewise constant formulation. Comparative simulations under ±30% atmospheric uncertainty demonstrate that, within critical velocity ranges, our improved algorithm elevates the trajectory altitude by approximately 36 km compared to fixed AoA methods. Notably, it reduces convergence time by 50% while strictly adhering to spacecraft physical performance boundaries. These results underscore the method's capability to provide robust, high-precision orbital adjustment support for aerocapture missions in uncertain atmospheric environments.
Tao, Kemeng
Vibration Simulation of Guide Mechanism Based on Rigid-Flexible Coupling Dynamics2026-99-03108/14/2026
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, Qing, Cheng, Zixiang, Zhuo, Changfei
Research on the Intelligent Design Method of Roof Frame Based on the Middle Layer and Component Technology2026-99-09078/7/2026
This study proposes an intelligent automotive roof frame design method based on the middle layer and component technology on CATIA. It aims to solve core roof modeling issues: determining geometric input quantity but uncertain attributes (tangent vectors, normal vectors, number of curve segments, number of surface patches, and boundaries), high manual interaction dependence, and poor knowledge reuse, to realize efficient design knowledge reuse. Methodologically, it builds a feature-driven parametric template, develops a knowledge rule-embedded componentized UDF library (reducing repeated modeling and geometric reconstruction needs), and integrates knowledge engineering for geometric input verification and operation direction control, eliminating curve/surface attribute uncertainty impacts. Verification shows the template stably generates roof crossbeams under simple/complex inputs, improving model robustness and reuse rate, reducing design workload, shortening verification cycles, and providing an extensible solution for white body design.
Jin, Chunning, Fu, Xinyu, Hou, Wenbin
Optimization of Pneumatic Conveying Elbows to Reduce Grain Particle Normal Contact Forces via CFD-DEM Coupling Method2026-99-01167/31/2026
This study presents a refined design for pneumatic conveying pipelines, featuring a grooved structure at the bend aimed at reducing particle breakage during transportation. Using soybean particles as a focus, the research employs a gas-solid two-phase flow approach to explore how different groove depths and widths influence the breakage rate. We used CFD-DEM simulation techniques, combining fluid mechanics with discrete element modeling to achieve a more accurate representation of particle motion and collision forces during expressing. Based on these simulations, we identified the most effective combination of groove width and spacing. Experimental results showed that a groove width of 4.5 mm coupled with a 40 mm spacing could decrease impact forces on particles by approximately 5% to 10% at expressing speeds of 15 m/s and 20 m/s. Throughout all measured time intervals, the impact forces remained stable, with turbulence exerting minimal influence on the particle forces.
Luo, Xinhao, Yang, Tiancheng, Huang, Bo, Mao, Genwu, Dong, Deliang, Shi, Heng, Li, Xiaoliang, He, Bo
Test and Simulation Analysis of Edgewise Compressive Performance of Marine Composite Sandwich Structures with Delamination Defects2026-99-02007/31/2026
In this paper, PTFE membranes were used to preform delamination defects, and VARI technology was employed to prepare marine composite sandwich structures with such defects. The cohesive zone model was used to emulate the interfacial bonding characteristics, thereby establishing a simulation analysis model to assess the edgewise compressive behavior of marine composite sandwich structures with delamination discontinuities. By combining experimental data with simulation results, the edgewise compressive resistance of marine composite sandwich structures was evaluated. Additionally, various parameters including the size, depth, quantity, and geometry of the delamination defects were studied to investigate their effects on the edgewise compressive performance of the marine laminated structures. The research results indicate that as the number of delamination defects increases, the edgewise compressive strength of the sandwich structure gradually decreases. Particularly, when the diameter of the layering defect is less than 30 millimeters, the influence of the defect on the edgewise compressive strength of the sandwich structure can be negligible. Conversely, when the diameter of the defect exceeds 30 millimeters, the rate of decrease in edgewise compressive strength increases significantly with the increase in the diameter of the defect, thereby greatly exacerbating the adverse effects of the delamination defects and ultimately resulting in a 10.77% reduction in the edgewise compressive strength. Furthermore, it was observed that the delamination defects located at the interface between the two panels and the core material on both sides of the sandwich structure do not affect each other, and to a certain extent, improve the compressive stability of the specimen. The degree of edgewise compressive strength reduction caused by elliptical delamination defects with the same area and long axis length is less than that of corresponding circular delamination defects, indicating that using circular delamination defects in the analysis of composite material structures with delamination defects is safer.
Zhang, Yao, Xu, Mingcai, Bian, Tianya, Zhou, Songqiang, Ji, Bing, Cheng, Jiahuan, Zhuang, Ya, Li, Xiang
A New Ternary Phase Diagram Prediction Descriptor Combined with Machine Learning Research2026-99-01807/31/2026
The morphological characteristics of ternary phase diagrams play a pivotal role in optimizing material properties and facilitating the design of novel alloys. In this study, machine learning (ML) is used to predict the number of phases in ternary alloy systems. A new feature descriptor for phase diagram prediction is proposed in ML, which includes the characteristics of element properties, thermodynamic properties of materials and CALPHAD parameters. Initially, this study constructed a dataset comprising various feature descriptors and validated their correctness employing ML models such as LRC, SVM, RFC, Bagging and GBDT. Subsequently, comparing the performance of different models, and the better-performing models Bagging and GBDT were selected for further prediction studies. The models were fine-tuned using grid search and random search methods to optimize their predictive performance. Ultimately, by predicting phase diagram data for multiple ternary systems at different temperatures, the accuracy rate near the temperature range of the given experimental data was approximately 82%. This demonstrates phase diagram descriptors in conjunction with machine learning to predict ternary phase diagram proposed in this study is practicable. The predicted data also provide guidance for experimental determination of phase diagrams and lay the foundation for future material design and optimization.
Fan, Hanchao, Su, Yu, Jin, Zongxiao, Li, Jun, Lee, Soowohn, Tang, Jianguo, Fu, Huaqing, Du, Zhi
Research on the Erosion and Wear Characteristics of Gathering and Transportation Pipelines by Cyclone Abrasive Process Parameters2026-99-01847/31/2026
Cyclone abrasive pigging technology, with advantages like environmental friendliness, easy construction, and low destructiveness, has broad application prospects. Studying how the process parameters affect the erosion-wear characteristics of gathering pipelines is crucial for improving pigging efficiency and effectiveness. This study adopted numerical simulations based on gas-solid two-phase flow erosion theory to explore such effects and verified the simulations via a self-designed experimental platform. Results showed that within the given parameter range, erosion rate rose significantly with velocity, especially at 20-30 m/s, peaking at 60 m/s; 0.6 mm abrasives and 0.25 kg/s mass flow rate led to higher erosion rates. Experimental data matched simulations with <10% error, confirming accuracy. Thus, cyclone abrasive process parameters significantly influence pigging performance, and the findings can guide practical operations within the studied range.
Wang, Haoran, Zhou, Xianjun, Li, Long, Song, Huifang, Zhang, Jin, Jv, Xiaolong
Desulfurization and Acid Resistance of Multifunctional Protective Coatings in Severe Environment2026-99-02387/31/2026
Desulfurization equipment in electric power industry is in a multi-field coupled corrosion environment with high temperature, high humidity, strong acid and solid-containing slurry. The annual direct economic loss of corrosion exceeds 5 billion yuan, and the equipment replacement cycle is only 1.5-2 years. Traditional protective coatings are difficult to meet the needs. The concept of “bionic barrier-intelligent response-in-situ purification” is proposed to construct multifunctional protective coatings: The Langmuir-Blodgett technique was used to alternately assemble MXene nanosheets and polysilazane. Ti-O-Si covalent bonds enhanced the interface bonding, resulting in a coating hardness of 4H and an elongation of 200%. After 1500 hours of extreme environment test, the coating has low weight loss rate, high self-repair and antibacterial rate, and its service life is extended by 8 times. The engineering application makes the maintenance period of desulfurization tower of a 660MW unit extended from 8 months to 6 years, saving 1.2 million yuan annually, and increasing 200,000 yuan annually by recovering H ˇ SO 2. It provides a cross-scale scheme for electric power corrosion protection.
Nie, Pengfei, Gao, Jiangyu, Chen, Wei
Engineering Practice of Sealing Design and Testing Technology for the Solar Array Drive Assembly of Tianhe Core Module2026-99-02437/31/2026
The Core Module of the space station is the first module of China’s Space Station, responsible for controlling the key parameters such as orbit, speed, and pressure of the entire space station, and serving as the control center of the assembly. The Solar Array Drive Assembly is a part of the Core Module. It needs to participate in the functional requirements of the whole cabin sealing of the cabin body, so it adopts the design scheme of semi-sealed. By adjusting the compression ratio and volume fraction of the sealing ring, and the roughness of the sealing surface, the overall sealing performance is improved. A small cavity leak detection hole is added to realize the sealing effect of detecting the second-layer seal separately. The real leakage rate of the drive mechanism is detected effectively by using multiple calibration schemes in the leak detection process, and the semi-sealing technology of the Solar Array Drive Assembly is verified, which has guidance and reference significance for the subsequent spacecraft design requiring a sealing function.
Dai, Fei, Zhu, Jiahao, Huang, Mengzhe, Qian, Zhiyuan
An Automatic Cleaning System for Copper Bar Chain of Cigarette Cutting Machine2026-99-01317/31/2026
The cutting machine is a critical component in the cigarette processing line, and its cutting quality depends on the operational condition of the copper bar chain. The grooves on the surface of the copper bar chain accumulate dust during the operation of the machine, which often causes unstable conveyance of raw materials, significant width variations, and a high defect rate. To address this issue, this study developed a linear reciprocating automatic cleaning system for copper bar chains to remove dust from the groove surface and hinge joints. Experiments have verified that the system improved the cutting qualification rate, increased the operational stability of the cutting machine, reduced manual cleaning workloads, and reached higher cleaning efficiency. This innovative system is also expected to provide a valuable reference for similar equipment manufacturers and advance technological innovation in the cigarette processing industry.
Li, Haitao, Zhang, Chunyuan, Fang, Junqing, Su, Lin, Chen, Peng, Guo, Zhiwei, Xing, Dongdong
Analysis of the Hot Forming Behavior of AZ91 Magnesium Alloy2026-99-08387/30/2026
This study systematically discussed the high-temperature flow behavior of the Mg-Al-Zn based AZ91 alloy, which has significant application potential in modern aviation and automotive industries. The study was carried out in the temperature range of 250°C-450°C and the strain rate range of 0.001 s^−1 -0.1 s^−1, which met the typical industrial hot processing environment. The analysis of high-temperature flow behavior shows that the flow stress is inversely proportional to the deformation temperature and is proportional to the strain rate. An important finding is that the constitutive model parameters are significantly sensitive to strain, so the strain-compensated Arrhenius constitutive model is developed. The model shows high accuracy in predicting the thermal flow stress of AZ91, and provides a valuable calculation tool for the simulation and optimization of forming processes in aerospace parts manufacturing. The results show that the extruded original microstructure presents slender fine grains, while the deformed sample shows a temperature dependent transformation: the low-temperature bimodal structure evolves into uniform fine grains at intermediate temperature, and the grains begin to coarsen at high temperature. At constant high temperature, low strain rate promotes grain growth and twin formation, while high strain rate refines grains and inhibits twins, and dislocation slip is the dominant deformation mechanism. These findings provide vital guidance and support for optimizing hot working parameters of AZ91, and are particularly important for manufacturing lightweight components in aircraft structures and automotive systems. The established process performance relationship is helpful to develop energy-saving manufacturing strategies for transportation equipment, and supports the goal of reducing weight and improving performance in the industrial field.
Li, Jusen, Chang, Ming, Zhu, Wenyu, Sun, Haoran, Chen, Kaida, Yang, Xiaoyin, Zheng, Zhenhao, Zhao, Shengdun
Design of a Digital Twin Interactive System for a 3D Printer2026-99-08597/30/2026
This paper takes a 3D Printer proposed by the project team in the early stage as the research object, constructs a digital twin entity including 3D models and data models in order to develop a digital twin interactive software. By activating the real-time correlation between 3D models and data models, valuable data exchange can be achieved between the digital twin entity and the physical entity, and valuable data can be used to drive both to refresh their operating status.
Li, Qi, Wu, WenKai, Lang, ZhiQi, Jiao, HongCheng, Jing, Tao, Zhao, HanTao, Dong, Shen, Shi, Lei
Research on Integrated Design and Optimization Method of High Speed Shuttle UUV Rudder and Propeller2026-99-08647/30/2026
Along with the advancement of the maritime power strategy, the research, development, and application of deep-sea space stations are becoming increasingly important. However, since deep-sea space stations mainly rely on acoustic communication, they cannot exchange information with ground stations quickly and accurately. To improve data transmission efficiency, this paper proposes using a high-speed shuttle UUV instead of acoustic communication. In this context, an efficient propulsion system is critical as it enables the UUV to achieve high speed and maintain stability. A propeller meeting the 110.9 N thrust requirement is designed using the chart design method, and the 110BL230-630 brushless DC motor is selected based on motor–propeller matching. This motor has a rated speed of 3000 rpm, rated power of 3000 W, and torque of 9.6 Nm. The performance curve of the NACA0012 airfoil is analyzed to select an appropriate rudder surface. The rudder area (4067 mm^2) is designed in accordance with DNV rules, with the following parameters: tip chord length 40 mm, root chord length 40 mm, and half-span 70 mm. CFD analysis is conducted on the designed propeller and the UUV equipped with the integrated propulsion system. The predicted performance of the P4119 propeller (hydrodynamic parameter deviation ≤ 1%) and the SUBOFF hull (resistance relative error ≤ 3.04%) confirms the accuracy of the CFD method for calculating propeller open-water performance and UUV drag. Through comparative analysis, the optimal rudder–propeller spacing is determined to be 60 mm, as this spacing yields the highest propulsion efficiency.
Wei, Jiaguang, Feng, Xiaowei, Zhao, Fuchen, Wang, Xingke, Xu, Shanzhi, He, Wenxuan
Influence of Modified Fly Ash Content on the Properties of Resin-Based Friction Materials2026-99-16577/24/2026
In this study, five resin-based brake pad samples with modified fly ash contents of 0%, 4%, 8%, 12%, and 16% were prepared to investigate the influence of fly ash content on the comprehensive performance of the friction materials. The tribological properties of all samples were evaluated under temperature conditions ranging from 100 °C to 350 °C, and their overall performance was assessed using five evaluation indices. Based on the AHP-MOORA algorithm, sample F12 exhibited the highest comprehensive weighted score of 0.11, followed by samples F0 and F8 with scores of 0.10 and 0.09, respectively, indicating a slight decline. In contrast, the comprehensive weighted scores of F4 and F16 were relatively low, at 0.05 and −0.01, respectively. Among the five composites, F12 demonstrated the best overall performance, with F0 and F8 ranking next, while F4 and F16 performed poorly. These results suggest that, within a certain range, increasing the fly ash content can enhance the comprehensive properties of the material. However, excessive addition of fly ash may lead to the detachment of harder particles during wear, thereby increasing wear thickness and wear rate.
Li, Xiaobiao, He, Kang, Zhao, Zhuanzhe, Wu, Bo, Sun, Fei
Optimization of Turbine Discrete Noise by Non-Uniformly Distributed Blade Design2026-99-16177/24/2026
The Mellin non-uniformly distributed moving blade method was adopted to conduct CFD numerical analysis and sample experimental tests on the axial-flow turbines before and after optimization using the uniformly distributed and non-uniformly distributed design methods, respectively. In the original design, five blades were evenly distributed in the 360° circumferential direction, and the non-uniformly distributed angles were 46°, 102°, 46°, 83°, and 83°. CFD numerical analysis shows that due to the low rotational speed of the turbine and the absence of a sealing structure at the blade tip, factors such as tip noise leakage and backflow have little impact, and the flow field pulsation is mainly caused by the blades themselves. The non-uniformly distributed design can significantly enhance the work-doing capacity of the blades. At 90% of the blade height, the torque can be increased by up to 60%, but at the same time, the axial force on the blades also increases accordingly. Near 80% - 90% of the blade height, the axial force increases by 33%. The flow rate performance of the non-uniformly distributed design is slightly inferior to that of the uniformly distributed design, but the overall noise is better than that of the uniformly distributed design, with maximum optimization of 0.48 dB (A); the maximum values of the first three orders of discrete noise are significantly improved, with a maximum improvement of 0.75 dB (A), and the discrete noise orders of the non-uniformly distributed turbine can avoid blade - related factors and disperse the energy to nearby orders.
Wu, Aiping, Ma, Tianli, Wang, Shiming, Ding, Chengling
Accurate Control of Refueling Volume for a New Type of Oil Change Device in the Reducer of Tobacco Machinery Equipment2026-99-16187/24/2026
In order to achieve precise control of refueling volume, improve oil change efficiency, reduce oil pollution and waste, a new oil change device for the reducer of the range hood equipment is studied. We design a new oil change device that integrates oil discharge and refueling functions based on the operating characteristics of the reducer in the range hood equipment. Using the rotational speed of the power pump and the flow rate of the oil pipeline as variables, we determine the refueling flow rate using a one-dimensional quadratic formula. Based on direct control theory, we optimize the relative position parameters of each component of the device, establish a control matrix, and achieve precise control. The experimental results show that the new oil change device exhibits good performance during both one-time oil discharge and refueling processes, meeting the precise control standards for refueling volume. The design and application of a new oil change device can effectively improve the efficiency and accuracy of oil change in the reducer of the range hood equipment, and have practical application value.
He, Pengtao, Wei, Bo, Liang, Zhiyuan, Deng, Weiren, Liang, Wenbin, Xing, Yuquan
Evaluation of Structural Service Performance of Low-temperature Modified Asphalt Pavement based on Peavy-Duty traffic Engineering2026-99-16457/24/2026
Relying on the reconstruction project, the low-temperature modified asphalt pavement significantly reduces the construction temperature of the asphalt mixture by 40 °C compared with the traditional asphalt pavement, and improves the road performance of the material. By comparing the two mixture rolling schemes, the compaction effect of scheme 2 is better. For AC-13 mixture, the flexural tensile strength of USP-SBS composite modified asphalt mixture is 0.67 MPa higher than that of SBS modified asphalt mixture, and compared with SBS modified asphalt mixture, the final rut depth of USP-SBS composite modified asphalt mixture is 2.68 mm shallower than that of SBS modified asphalt mixture, and the total deformation rate is 43.8% lower than that of the latter. The post-construction quality evaluation shows that the stability of the low-temperature modified asphalt pavement test section under the bearing capacity and high-temperature-water coupling is better than that of the conventional road section, and the low-temperature stability is comparable to that of the two. This innovative application not only achieves energy saving and emission reduction but also provides a new solution for road construction under heavy traffic conditions.
Liu, Chuanfeng, Xu, Ke, Shi, Zheng, Hao, Jidong, Zhao, Liandi, Xianwei, Wang
Analysis and Experimental Research on The Impact of the BangBang Valve Switch on the Flow Rate of the Storage and Supply System2026-99-16157/24/2026
This article focuses on a wide range of high-precision storage and supply systems. Under the rated flow rate of 2.928 mg / s of the proportional flow controller, the instantaneous flow fluctuation range of the BangBang valve reaches 2.963 mg / s, exceeding the control accuracy requirement of 1% for the proportional flow controller. By establishing mathematical models of the BangBang valve, proportional valve, and proportional flow controller for simulation analysis, the trend of the simulation results is consistent with the experimental results. Furthermore, considering the spatial layout and weight of the storage and supply system, this paper proposes a method to improve the accuracy of flow output by adding 180 mL of air capacity between the proportional valve and the proportional flow controller. Ultimately, the maximum flow fluctuation of the proportional flow controller at the moment of the BangBang valve opening and closing is 2.941 mg / s, which meets the control accuracy of the proportional flow controller. Moreover, the error between the output flow rate of the proportional flow controller and the rated working flow rate is minor after increasing the air capacity.
Li, Zhong, Li, Zongliang, Yan, Zelong, Huang, Tiankun
North American CAV Performance Data StandardWP-00157/22/2026
As the deployment of connected and automated vehicles (CAVs) expands, the need for a consistent, cross-industry approach to performance relevant CAV data exchange is becoming more pressing. Vehicle developers, infrastructure owners and operators (IOOs), and technology providers generate and consume data that support safety, mobility, and operational efficiency, yet much of the data remains fragmented, inconsistently formatted, and difficult to reuse across systems. To address these gaps, the Society of Automotive Engineers (SAE) and the Canadian Standards Association (CSA) convened a multi-stakeholder workshop on November 3, 2025, with participants representing original equipment manufacturers (OEMs), automated driving system (ADS) developers, state and local agencies, standards bodies, and technology partners. The workshop focused on identifying challenges, clarifying needs, and outlining a path toward a North American CAV Performance Data Standard. Key themes from the workshop included: -The need for a shared data language to support safe and interoperable CAV operations. -The lack of consistent formatting, labeling and visibility regarding who produces and consumes data. -A “start small, iterate and scale” approach beginning with well-defined use cases. -The need for technical harmonization and governance structures that build trust and support sustained coordination. This white paper summarizes the key findings and outlines a practical approach to developing a Version 0.1 base-layer data standard that can support measurable progress in 2026 and beyond.
Nesheli, Mahmood
Definition and Introduction of Digital Mesh/Digital Fabric FrameworkAIR8614 (Current)7/21/2026
The proposed Digital Mesh/Fabric concept builds upon the Digital Thread Framework (refer to AIR7161) by representing the interconnection of multiple digital threads across multiple data stores, logical organizing segments, and product life-cycle stages. Unlike a single digital thread, which follows a linear or sequential flow of data utilization through a product life cycle, the Digital Mesh/Fabric forms a complex mesh of n-dimensional interconnected digital threads, allowing for greater value creation, flexibility in data utilization, scalability, and integration.
G-31 Digital Transactions for Aerospace
Design of Carrier-Based Aircraft Landing Control Law Based on First-Order Linear Active Disturbance Rejection Control2026-99-18357/17/2026
This paper investigates the high-precision landing control problem of carrier-based aircraft. An Active Disturbance Rejection Control (ADRC) technique is employed to design longitudinal and lateral-directional landing control laws. The landing process is simulated by incorporating an airwake model, and the results are compared with those of a PID control law. The analysis demonstrates that the proposed ADRC controller reduces lateral deviation errors and significantly improves landing accuracy and success rate.
Yu, Jiayang, Yin, Yong
A Method for On-Orbit Testing of Long-Term Docking of Manned Spacecraft at the Space Station2026-99-18487/17/2026
To ensure the successful implementation of the separation, evacuation, and return processes of manned spacecraft after long-term docking at the space station, regular on-orbit health assessments must be conducted. Based on this requirement, a technical method for evaluation through autonomous on-orbit testing is proposed. First, the docking status and characteristics of the manned spacecraft’s systems, such as information management, crew environmental control, thermal control, power management, docking function, attitude, and orbit control function, are described. Then, the functional requirements for the separation, evacuation, and return of the manned spacecraft, such as the relative measurement, the relay communication, TT&C and data transmission, image and voice, instrument display and alarm, and the attitude measurement, are analyzed. Subsequently, the on-orbit testing system, test items, test procedures, and test methods for health assessment are detailed. It also provides the design of TT&C support, the design of energy support, and the main principle explanation for autonomous on-orbit testing of the system.
Cheng, Wei, Nan, Hongtao, Tian, Ye, Zhao, Zheng
Multi-sensor Data Fusion Based on Big Data Modelling2026-99-05687/10/2026
The collection of road high-frequency data often involves inputs from multiple sensors, such as stress and strain, and sampling of these data features a high sampling rate of up to 2,000 Hz. High-frequency sampling enables capturing of the internal stress and strain of the pavements when vehicles are passing and facilitates the analysis of the pavement structure and prediction of its long-term service performance. However, while the sensors are continuously collecting data, the time the vehicles pass is discrete and unpredictable, resulting in a large number of low information density or irrelevant data. Even when the massive high-frequency data are collected, challenges remain in data transmission, storage, and analysis—the challenges are attributable not only to the massive quantity and complexity of data from multiple sensors, but also to the inconsistent data formats, misaligned timestamps, and multi-sensor data fusion difficulties. In response to the challenges specified above, a new approach combining traditional road observation data with deep learning models is proposed here to efficiently process and analyze massive sensor data. This method not only improves the data processing efficiency but also provides new insights into innovation of road engineering technologies.
Gang, Jian, Zhang, Yue, Chen, Yinghao, Zheng, Xiaoyan, Wang, Taojie, Liu, Yilin, Guan, Wei, Wu, Jiangfeng
Optimization Method for Emergency Rescue Resource Allocation in Two-Way Ten-Lane Expressway Based on Risk Assessment2026-99-05677/10/2026
The two-way ten-lane expressway has the significant characteristics of “large traffic volume, mixed vehicle types, and heavy loads”, which makes the impact of traffic flow status on accident risk present nonlinear characteristics. Traffic flow fluctuations not only directly affect the probability of accidents, but also amplify the spatiotemporal differences in rescue needs through mechanisms such as lane occupancy time and accident chain reactions. Therefore, the essence of resource allocation on a two-way ten-lane expressway is the “spatiotemporal matching problem between dynamic risks and limited resources”, which requires both quantifying the spatiotemporal evolution of risks and coping with the high uncertainty of the traffic system. Aiming at the problem of inefficiency of traditional empirical resource allocation under complex traffic conditions, this study proposes a dynamic optimization framework based on multidimensional risk assessment for emergency rescue resource allocation. In this framework, firstly, the entropy weight method and fuzzy comprehensive evaluation are combined to construct a risk quantification model using historical accident data and real-time traffic characteristics to achieve fine risk classification of road sections. Secondly, a multi-objective optimization model is established with the goal of minimizing risk-weighted costs and maximizing risk-weighted resource demand satisfaction, and considering constraints such as mandatory requirements for key equipment in high-risk areas and minimum site configuration. At the same time, the improved NSGA-II algorithm is used to effectively solve the contradiction between cost and utilization efficiency in emergency rescue resource allocation through adaptive non-dominated sorting, hybrid genetic operators and dynamic penalty mechanism. Experimental results show that the improved NSGA-II algorithm is superior to the traditional method in terms of Pareto front distribution, convergence speed and actual resource allocation effect. Compared with the traditional scheme, the method proposed in this study reduces the resource allocation cost by 35.5%, increases the risk-weighted resource demand satisfaction rate by 1.9%, and expands the resource coverage of high-risk areas by 13.8%. This study provides scientific decision-making support for emergency response in complex road networks and offers a practical optimization approach for highly dynamic traffic emergencies.
Kan, Youjun, Cao, Yang, Shi, Xiaomin, Gao, Shangjie
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