Browse Topic: Design Engineering and Styling

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J1979 Enhanced DBCJ1979DBC_202609To be published on 09/07/2026
The SAE J1979 Enhanced 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 Enhanced DBC file with Includes 2,400+ Parameter Group Numbers (PGNs) and 16,000+ Suspect Parameter Numbers (SPNs), derived from the J1979 Digital Annex (DA) 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.
Mechatronic Transfer Wheelchair Based on SLAM, A*/DWA Algorithms, and Finite Element Safety Assurance2026-99-03418/14/2026
With the acceleration of population aging, the number of disabled older people is increasing, and the demand for home care is also rising. In the case of a narrow space and no gap between the bed and the ground, the transfer of patients between the wheelchair and the bed has become a challenge. Current solutions suffer from bulky designs, require caregiver assistance, and pose potential safety risks. In order to solve the above problems, this paper proposes an intelligent transfer wheelchair with voice interaction and autonomous navigation function. The wheelchair innovatively adopts a cantilever transfer device, which can enable safe and stable transfer without requiring bed-floor clearance, and has the dual functions of a wheelchair and a transfer device, effectively saving family space. The stability of the structure is verified by finite element analysis. Under the action of a 500 N load, the maximum stress and maximum displacement are within the safety limit of the material. The wheelchair is also equipped with an advanced human-computer interaction system with voice interaction and autonomous navigation functions. Users can control the operation of the wheelchair through voice. The navigation module of SLAM and the hybrid A*/Dynamic Window Approach (DWA) path planner realizes the high-precision docking of the wheelchair and the bed. The results show that the design can realize the safe transfer of disabled people between wheelchair and bed, and provide a solution for home intelligent nursing.
Wang, Shunli, Peng, Li, Zhao, Liang
Stress Analysis and Simulation Study of Propane Spherical Tanks2026-99-03348/14/2026
As special pressure-bearing vessels, spherical tanks are widely used in chemical, oil refining, and other fields. However, their safe operation faces the dual challenges of structural failure and leakage diffusion. Meanwhile, due to its low lower explosive limit and the low ignition energy required, propane will evaporate rapidly after leakage to form an explosive mixed gas, which may further trigger severe accidents such as combustion and explosion. Therefore, this paper takes a 3000 m3 propane spherical tank as the research object, comprehensively applies the finite element analysis method, and systematically researches stress distribution, aiming to provide theoretical support for the safety design of spherical tanks and accident prevention and control.
Huang, Yuanxuan, Tao, Gang, Zhang, Lijing
Reliability Calculation and Analysis of Influencing Factors for Girth Welds in High-Grade Steel Pipelines Based on HMC-SS2026-99-03428/14/2026
Fracture failure of girth welds in high-grade steel pipelines poses a critical threat to pipeline integrity. Leveraging enhanced digitalization in pipeline engineering, a statistical database has been developed to support reliability analysis based on actual operational data. This study utilizes real project data to analyze the failure probability and key influencing factors of girth welds containing crack defects, thereby providing theoretical support for safety design and risk management. To overcome the conservatism of traditional deterministic methods, a probabilistic reliability model was established, incorporating a modified PRCI-CRES ultimate tensile strain criterion. Addressing the inefficiency of standard Monte Carlo (MC) simulation in high-dimensional low-probability contexts, an efficient Hamiltonian Monte Carlo-Subset Simulation (HMC-SS) strategy was introduced. Results show that HMC-SS improves computational efficiency by 99.95% over MC, with only 0.90% relative error. Key findings include: crack depth has the strongest influence – variation from 0.92 mm to 3.68 mm, which increases failure probability by 103 times; the strength matching coefficient is dominant, and higher values reduce failure risk; strain demand exhibits a positive correlation with failure probability and couples with material properties. It is concluded that high- or equal-strength material matching should be emphasized in welding, and reliability-informed design should account for multi-parameter interactions to ensure global safety.
Yang, Kai, Wang, Kaihong, Wang, Bin, Shao, Jia, Yu, Weichao, Zhang, Dong
Anti-splash System of Sprinkler Based on Millimeter Wave Radar and Machine Vision Fusion2026-99-03238/14/2026
In view of the problems that it is difficult to accurately control the spraying area of the mining sprinkler, and the resource waste caused by the mis-spraying material stacking area, as well as the failure of traditional radar monitoring in the complex electromagnetic environment, this paper proposes an anti-splashing system for the mining sprinkler. By combining millimeter wave radar and visual recognition fusion technology, the overall scheme of the anti-splash system is proposed. Then the control simulation of the whole system is carried out. The results show that the problem of poor control in traditional sprinkler operation can be effectively solved, and the sprinkler area can be adjusted intelligently. Finally, in order to verify the accuracy of the algorithm used in this paper, different algorithms are used for comparative experimental verification. The results show that the Modified YOLOv4 algorithm has a high accuracy of 98.75 %, which has good applicability and provides a theoretical basis for subsequent research.
Hou, Lin
Comparative Study on the Strength Calculation Method for Pumped-Storage Power Plant Head-Cover-to-Stay-Ring Bolts and on Relevant Preload and Strength Standards2026-99-03248/14/2026
Head-cover-to-stay-ring bolts in pumped-storage plants face fatigue fracture risks due to axial alternating loads, with catastrophic failure cases reported globally. In China, the absence of a unified design code in early projects produced widely divergent bolt designs. This study proposes a hybrid “field measurement and Computational Fluid Dynamics (CFD) correction” method to analyze bolt forces under turbine load-rejection transients (max. stress: 780 MPa, error <3.1%), benchmarks three Chinese standards (GB/T 22581-2024, NB/T 10135-2019, GB/T 15468-2020) for preload design, and refines their technical clauses to provide actionable guidance for future tender specifications and long-term bolt maintenance.
Long, Zhe, Guo, Meichao, Kang, Caini, Li, Chengjun
Comparative Analysis of CDTire Model and FTire Model in Vehicle Comfort and Durability Simulation2026-99-03018/14/2026
Applicability of the CDTire tire model in vehicle handling and stability simulations is studied in this paper by comparison with the PAC2002 tire model. Based on the physical tire 245/50 R20, corresponding CDTire and PAC2002 models are established and assembled on the multibody dynamics model of an SUV. After simulating 5 handling and stability conditions, it is found that the CDTire calculation is more time-consuming compared with PAC2002, but the increased time cost does not exceed 10%. In addition, the relative errors of the 17 evaluation indices obtained based on CDTire compared to PAC2002 do not exceed 5%. Therefore, in terms of both computational accuracy and efficiency, CDTire is suitable for application in vehicle handling and stability simulation.
Gao, Fengling, Wu, Wenwen, Fei, Yuanjun
Research on the Assembly Sequence Planning Algorithm under Cabin and System Constraints2026-99-03458/14/2026
Assembly sequence planning is a crucial part of process preparation in aircraft final assembly. A scientifically designed assembly sequence can significantly improve assembly efficiency and reduce costs in aircraft production. Efficient planning not only streamlines the workflow but also minimizes potential errors and rework, which are critical in high-stakes aviation manufacturing. This paper examines the constraint relationships in aircraft assembly from the perspectives of cabin constraints and system constraints, covering both spatial layout restrictions and functional logical dependencies to ensure the comprehensiveness of constraint analysis. It establishes a directed graph for the aircraft assembly outline and generates the corresponding adjacency matrix, which converts the complex constraint relationships into a structured mathematical expression for easier subsequent algorithmic processing. The Warshall algorithm and Johnson algorithm are used to check and extract contradictory constraints from the directed graph. The adjacency matrix is then employed to calculate the reachability matrix, which helps identify redundant constraints and reduces the computational effort in assembly sequence planning. Finally, the optimized constraint relationships are used to calculate the aircraft’s final assembly sequence, which generates a Gantt chart for assembly sequence planning, guiding the on-site assembly order and accelerating aircraft development efficiency. The integrated approach effectively addresses the key challenges in complex aircraft assembly sequence planning.
Guo, Jingjing, Cun, Wenyuan, Zhao, Jiong, Yu, Yang, Yang, Rui, Yu, Long
Research on Rigidity-Intensity Analysis and Structural Optimization of the Shuttle Vehicle Load-Bearing Plate2026-99-03068/14/2026
The shuttle vehicle is a critical piece of handling equipment in automated logistics warehouses. As its primary load-bearing component, the load plate is subject to spatial constraints, requiring both a compact structure and effective prevention of structural deformation that could compress the battery. For a shuttle vehicle load plate developed by a company—with a rated load of 1500 kg and a maximum allowable deformation of ≤ 2 mm—this study first adopts the finite element method (FEM) to analyze its structural characteristics and establish a hybrid mesh model consisting of 1D beam elements, 2D shell elements, and 3D solid elements. Symmetry constraints are applied to reduce the computational scale. The structural deformation and stress under two constraint schemes (fixed constraints and surface-to-surface contact constraints) are compared and analyzed. The results indicate that surface-to-surface contact constraints should be adopted under this working condition, and potential design risks are identified. During the analysis, mesh independence is verified to determine an appropriate mesh size, thereby avoiding errors induced by mesh dimensions. Finally, an optimization design is conducted with the goal of lightweighting. Taking the cross-sectional dimensions of the load plate’s stiffeners and the thickness of the load plate as variables, and deformation as the constraint condition, the overall structural weight is reduced from 32.7 kg to 29.6 kg through multiple gradient-based iterative optimizations, effectively achieving the lightweighting objective. Experimental results show good consistency with the computational predictions. Additionally, the manufacturing process requirements and cost impacts of the optimized scheme are analyzed, and a manufacturing solution that meets technical requirements while ensuring economic feasibility is proposed.
Liu, Rui, Shen, Jie, Chen, Meng
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
Dynamics of Quayside Container Cranes with Anti-Wind Devices under Strong Winds2026-99-03198/14/2026
Quayside container cranes (QCCs), essential for cargo handling in seaport operations, are particularly vulnerable to damage under strong wind conditions. This study investigates the wind-induced dynamic behavior of QCCs equipped with active anti-wind systems, focusing on the mechanisms that govern cable stress and sliding instability. A five-degree-of-freedom mathematical model is established, incorporating nonlinear cable stiffness, restricted sliding through a Kelvin-Voigt collision model, and a combined Stribeck-Coulomb friction model for the wheel-rail interface. Parametric studies are conducted to evaluate the influence of three key factors, the anti-wind cable diameter, the sliding displacement of the QCC wheel, and the wheel-rail friction coefficient, on cable stress responses. The results show that increasing the cable diameter and friction coefficient significantly reduces peak cable stress, whereas greater sliding displacement increases stress accumulation and structural vulnerability. Sensitivity analysis reveals that cable diameter has the most dominant effect on cable stress, followed by sliding displacement and friction coefficient. This work might provide theoretical foundations for the design and optimisation of wind-resistant QCC structures, as well as for the development of more reliable anti-wind protection systems in extreme conditions.
Xiang, Lei, Ji, Huanyu, Liu, Zhiwei, Wang, Ziyou, Xu, Xinyue
Finite Element Analysis of New Energy Vehicle Chassis Using ANSYS2026-99-03438/14/2026
Amid the rapid development of the new energy vehicle industry, the vehicle frame, as the core load-bearing component of the entire vehicle, plays a direct role in the vehicle’s safety, lightweight design, and power performance through its design and performance. Although research on new energy vehicle frames has matured, issues related to the lightweighting of drive shaft-associated structures and the balance between weight reduction and strength/stiffness still require in-depth exploration. This study focuses on the chassis of new energy vehicles, utilizing Q295 low-alloy high-strength steel. Based on the vehicle’s dimensions and mass parameters, a simplified 3D model was constructed using SolidWorks. Static analysis under bending and torsion conditions, along with a 6th-order modal analysis, was conducted using ANSYS software. Based on the analysis results, optimizations were implemented at both structural and material levels: structurally, the central crossbeam was widened, holes were opened on the crossbeam’s vertical plane to reduce weight, and the longitudinal beam welding process was optimized; materially, Q295 steel was retained in high-stress zones, while aluminum alloy replaced it in low-stress zones. The optimized frame achieved a 15% reduction in torsional stress, a 16% decrease in bending stress, a 2% reduction in torsional deformation, and a 3% decrease in bending deformation. Total mass decreased by 12.7 kg, with both strength and stiffness meeting design requirements. This approach synergistically enhances frame lightweighting and performance, providing technical support for optimizing the overall performance of new energy vehicles.
Guo, Lihong, Wang, Yiyou, Yang, Zihao
Optimization and Control of Mechanical Testing for Batch-Produced Manned Spacecraft2026-99-03128/14/2026
To safely, efficiently, and high-quality complete the mechanical testing of batch-produced manned spacecraft during the China Space Station (CSS) phase, a series of optimization measures were proposed based on system engineering principles. These measures cover the entire mechanical testing process from preparation to implementation, including: establishing a standardized mechanical testing documentation system; reducing the number of mechanical sensors that do not affect result evaluation; pre-identifying and measuring background noise; digitizing test notching and evaluation methods; and standardizing and automating testing procedures. Additionally, targeted measures for test safety and quality control were implemented, including regular inspections of reusable spacecraft components, strict control of test hazards and operational risks, and standardized management of ground support equipment (GSE) through regular inspections. The proposed optimization and control measures have been validated through applications in batch-produced manned spacecraft during the CSS phase. The results show that: the generalization rate of mechanical testing documentation exceeds 80%; the number of mechanical sensors has been reduced by more than 10%; the test preparation period has been shortened by over 4 days; test efficiency has been improved by 30%; the single-direction test duration has been reduced by more than 50%; and the total test cycle has been shortened by 25%. These results indicate that the proposed optimization and control measures are reasonable and feasible, which effectively reduces redundant test operations and items, lowers potential test risks, improves test efficiency, shortens the overall test cycle, enhances test safety, and ensures the high-quality completion of mechanical testing for batch-produced manned spacecraft.
Peng, Huakang, Wang, Mengchen
Research on Wind-Induced Vibration Response of Heavy Cargo Ropeways for Power Transmission Lines2026-99-03308/14/2026
The construction of overhead power transmission lines in remote mountainous regions frequently relies on aerial ropeway systems, as conventional ground transportation is often impractical. However, complex terrain conditions combined with highly variable wind environments can significantly threaten the operational stability and structural safety of these cargo ropeway systems. To investigate these effects, a refined finite element model of a ropeway support was developed in ANSYS, and stochastic, time-varying wind fields were generated in MATLAB. The simulated wind time histories were applied to the numerical model to perform nonlinear transient dynamic analyses, enabling the evaluation of wind-induced displacement responses under different wind angles of attack. Based on the simulated response histories, critical stress- and displacement-sensitive regions of the support structure were identified, and the implications for structural detailing and design optimization of cargo ropeway supports were discussed.
Lv, Yanfeng, Yang, Zhonglv, Sun, Minggang, Jin, Hengdong
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
Influence of Roundness and Geometric Errors on Lubrication Performance of Engine Journal Bearings2026-99-03218/14/2026
This paper focuses on the critical issue of lubrication performance in journal bearing manufacturing, employing numerical simulation techniques to investigate how manufacturing errors from processing accuracy impact lubrication behaviors. As core components in mechanical systems—especially diesel engine crankshaft bearings operating under complex conditions—journal bearings’ lubrication performance directly determines equipment stability, energy efficiency, and service life. Manufacturing deviations-induced poor lubrication can cause increased friction, severe wear, or even failures, underscoring the research’s practical value. The study constructs a refined numerical model based on the Navier-Stokes equations within the Computational Fluid Dynamics (CFD) framework, ensuring it reliably depicts fluid flow in bearing clearances. It then systematically analyzes the lubrication responses of diesel engine crankshaft bearings under diverse operational scenarios, varying key manufacturing-related parameters: roundness degrees and clearance dimensions, which mimic real production discrepancies like tool wear or machining vibration. Additionally, the research explores shaft center trajectory variations under two extreme operating conditions, as shaft movement reflects the lubrication film’s loadbearing and stability capacities. Surface roundness and clearance are identified as pivotal to journal bearing performance: they significantly alter oil film thickness distribution—critical for avoiding metal contact—and determine the maximum fluid pressure within bearings, a key load-bearing indicator. Moreover, the amplitude and phase angle of roundness fluctuations (often overlooked) exert substantial impacts on lubrication stability and load-bearing properties, offering insights for optimizing manufacturing processes to mitigate such adverse effects: -Journal bearings. -hydrodynamic lubrication. -Form error.
Liu, Jun, Liu, Deliang
Bi-Directional Evolutionary Topology Optimization Design for Rib Structures2026-99-03148/14/2026
The performance of modern high-speed aircraft is intrinsically linked to structural mass. As a key component that generates lift, the shape and lightweight of the wing are crucial for improving aircraft performance. This study employs the bi-directional evolutionary structural optimization (BESO) method to perform topology optimization on the wingrib structure of a modern high-speed fighter aircraft. Minimize the overall strain energy as the objective and use the wing rib volume fraction as the constraint to perform topology optimization design on the wing ribs. Based on element stress/strain energy density criteria, the method iteratively adds or removes material to efficiently construct optimal load-transfer paths within the rib configuration. Following the redesign according to the optimized topology, the structural mass was reduced by 39.236% while satisfying strength and stiffness constraints. Results demonstrate that the BESO methodology effectively generates high-efficiency load-bearing configurations for wing ribs, significantly improving material utilization efficiency and structural performance while substantially reducing wing mass. This research provides an effective approach for lightweight design and performance enhancement of critical load-bearing structures in modern high-speed aircraft.
Zhou, Lei, Wang, Wei, Gong, Quanwei, Zhou, Jingchao, Guan, Shenxiaoge
Design of a Four-Wheel Turning Tobacco Harvester Suitable for Hilly Areas2026-99-03338/14/2026
To address the core requirement of “layered ripeness and non-destructive harvesting” in tobacco-growing hilly regions of China, a specialized tobacco leaf harvester was developed. Considering the challenges posed by scattered plots and complex terrain, a four-wheel steering chassis system was proposed. The platform adopts a four-wheel independent drive and steering (4WID-4WIS) configuration, powered by DC servo motors and integrated with a microcontroller-based ROS system. The resulting drive chain—comprising motors, gear reducers, and off-road tires—achieves a maximum operating speed of 0.5 m/s. A novel rotary cross-blade harvesting module was designed in conjunction with a conveyor-based transmission mechanism, enabling stratified harvesting and leaf transport. Full-condition field tests were conducted. In terms of mobility, the harvester achieved stable operation at 0.5 m/s on cement roads, 0.1–0.2 m/s in fields, and demonstrated slip-free climbing on 20° slopes. In terms of harvesting performance, the system’s adjustable modules accommodated varying plant heights; however, issues with blade grip were observed when handling irregularly slanted stalks, affecting collection efficiency. During continuous field entry and exit operations, no mechanical failures occurred, verifying the prototype’s operational stability. This study introduces an innovative combination of omnidirectional mobile chassis and stratified blade modules, offering technical support for the modernization of tobacco agriculture. Further refinement of the harvesting strategy will be pursued to enhance practicality.
Guo, Ting, Gu, Jin, Li, Wen, Tang, Xiaoming, Long, Chao, Yang, Dongchao
Modeling Method of Aircraft Hydraulic Pipeline Cleaning Test Equipment Based on MBSE2026-99-03318/14/2026
With the continuous improvement of performance requirements for aviation equipment, the importance and complexity of hydraulic systems as the core carrier of flight control are becoming increasingly prominent. The cleanliness of aircraft hydraulic pipelines directly affects the reliability and flight safety of hydraulic systems, and it is necessary to use specialized cleaning and testing equipment during design and manufacturing to achieve efficient cleaning. The design of traditional cleaning equipment relies on experience-driven development, with mechanical, hydraulic, and electrical systems developed independently. There are problems such as unclear requirement definitions, low efficiency of interdisciplinary collaboration, and lagging validation, making it difficult to achieve the goal of forward design. Therefore, this study introduces Model-based Systems Engineering (MBSE) method in the development process of pipeline cleaning test equipment, proposes a modeling process based on RFLP (Requirements-Function-Logical-Physical), and uses SysML system modeling language to construct a top down design model system for aircraft hydraulic pipeline cleaning equipment. Through requirement analysis modeling, functional behavior definition, and system architecture design, the significant advantages of MBSE method in the development of complex aviation test equipment have been verified, effectively improving the bold design capability and top down design efficiency. MBSE method can not only improve the design efficiency of equipment, but also promote the intelligent and efficient operation of equipment, which has important significance for the development of intelligent manufacturing and electromechanical integration technology.
Zhang, Yuxin, Ma, Zichen, Li, Qi, Song, Guoqiu, Li, Haiwei, Zhang, Jingjing
Research on Asymmetric Gear Stiffness2026-99-03328/14/2026
To meet the need for optimizing the dynamic performance of asymmetric gear transmissions operating under high-speed and heavy-load conditions, this study presents a refined stiffness modeling approach. A tooth-surface contact stiffness model is formulated based on Hertzian contact theory. By integrating the energy method, a coupled stiffness model is established that incorporates bending, shear, axial compression, and foundation stiffness components. Stable curves depicting the variation of mesh stiffness with the path of contact are subsequently derived by leveraging the principle of stiffness superposition. The findings demonstrate that the proposed mathematical model accurately represents the stiffness behavior of asymmetric gears as governed by the changing contact length, thereby providing a theoretical foundation for enhancing gear dynamics and extending the service life of transmission systems.
Zhao, Zeyi, Sun, Xiaoyan, Wu, Ziheng, Tang, Xin, Liu, Yanxia, Li, Fajia
Failure Analysis of the Safety Valve Spring in a Dangerous Goods Tanker2026-99-03138/14/2026
During the operation, a spring in the built-in safety valve of a dangerous goods tanker. A comprehensive failure analysis of the material was conducted through macroscopic and microscopic inspections, metallographic analysis, energy spectrum analysis (EDS), and hardness tests. The failure mode of the broken spring was brittle fracture. The fracture morphology was like that of ice sugar, and the chemical composition of the spring steel met the specified requirements. The main cause of fracture failure is the mechanical damage to the inner surface during the spring manufacturing process, which leads to stress concentration in the damaged area and ultimately results in fracture. In addition, manufacturers should strengthen and standardize the production process to prevent mechanical damage and select high-purity spring steel to improve the durability of the springs.
Yang, Lijun, Li, Qingshan, Xiong, Mingming, Liu, Mingming, Wu, Junyao, Yu, Lang, Zhang, Zewei, Xie, Xumeng
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
Study on an Infrared Detector Parameter Measuring System2026-99-03028/14/2026
This work introduces a novel parameter measurement model for an infrared detector. Firstly, the models for calculating the parameters of an infrared detector are studied and established, such as hysteresis, repeatability, and sensitivity. Then, experiments are implemented to validate and analyze the aforementioned parameters, demonstrating the accuracy and validity of the parameter computation model. This research has guiding significance for the accurate measurement of the index parameters of infrared detectors, and it is also helpful for the calibration method, error analysis and correction of infrared detectors.
Hu, Changde, Li, YongQiang, Miao, Qi, Gao, Sili, Liu, Xiangyao, Li, Kunqi
Analysis of the Influence of the Centroid Distribution of the Raft on the Shafting Alignment2026-99-03048/14/2026
Aiming at the problem of shaft alignment disturbed by the centroid distribution of the raft in the ship propulsion system, the quantitative influence of centroid offset on bearing load distribution and axis deformation is revealed. Based on the theory of an elastically supported continuous beam, the finite element model of the raft-shaft coupling system is established. By adjusting the position of the raft counterweight mass point (longitudinal offset range ±0.5 m) to simulate the centroid change, the static solution algorithm is used to analyze the key parameters, such as bearing load and axis alignment accuracy, under multiple groups of centroid offset conditions. It is concluded that when the centroid of the raft moves to the propeller end, the load of the 1# and 2# bearing near the propeller end increases, and the load of the 3# and 6# bearing near the thrust plate end decreases. The lateral offset of the center of mass increases, the axial offset at the stern bearing increases, the maximum deflection of the shafting increases, and the deformation of the raft structure increases. The centroid distribution of the raft is a disturbance source of the shafting alignment state, and its offset will reconstruct the bearing load distribution and cause the axis deformation. It is recommended to control the lateral offset of the center of mass at the design stage and reserve the dynamic compensation margin for the shafting alignment.
Yin, Hong, Jin, Yong, Wang, Jun, Tian, Jiabing
Structural Design and Mechanical Performance Analysis of Key Components of Deicing Robots for Transmission Lines2026-99-03468/14/2026
Extreme winter weather often leads to ice accretion on transmission lines. Manual removal is inefficient, costly, and poses safety risks. To address this issue, this paper presents the design of a de-icing robot to replace manual operations for transmission line de-icing. The main content focuses on the detailed structural design of the robot, including the mobile platform, de-icing mechanism, and adaptive adjustment module. Finite element simulations are conducted on key components to verify the structural rationality and the correctness of material selection. The proposed de-icing robot enhances the safety of the de-icing process, improves operational efficiency, and provides a valuable reference for transmission line de-icing methods, demonstrating significant practical value.
Chang, Hao, Zhen, Chen, Han, Fengmei, Li, Cheng
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
Strength and Rotor Dynamic Simulation Analysis of a Brake Testing Device2026-99-03278/14/2026
The brake test bench is an effective method for studying wheel-rail interaction by simulating the braking process of rail vehicles. To ensure the safe and reliable operation of the brake test bench, this article focuses on introducing a comprehensive single-wheel brake test device. A finite element model of the wheelset assembly and test bench was established, and the strength, mode, and dynamic performance of the wheelset assembly and braking system were analyzed by simulating the braking process. The analysis results indicate that the wheelset assembly and braking system meet the strength requirements of the braking test process, and the test speed is maintained below the critical speed of the test bench. This validates the rationality and safety of the brake testing device and provides a foundation for subsequent brake research.
Jing, Yuhang, He, Taixiong, Song, Ye
Dynamic Sliding-mode Control with Backstepping for Offshore Boarding Gangway2026-99-03398/14/2026
This paper focuses on the control challenge of the movable ladder section of an offshore boarding ladder. A dynamic sliding mode control (DSMC) method based on the backstepping approach is proposed. To address the disturbance mismatch problem in traditional control strategies, the backstepping approach is adopted for the hierarchical design of the control law, decomposing the complex nonlinear system into low-order subsystems for step-by-step processing. Meanwhile, by integrating the strong anti-disturbance advantage of DSMC, a composite control framework with disturbance compensation capability is constructed, which effectively suppresses the nonlinear disturbances caused by external disturbances and system parameter perturbations during the movement of the movable ladder section. The stability of the proposed control method is strictly proven using the Lyapunov function. Simulation results show that the speed response adjustment time of the movable ladder section is less than 10.3 ms, and the position tracking error is controlled within 1.03 mm. Compared with the traditional PID control, the rise time of DSMC is improved by 89.16%, and the tracking accuracy is improved by 90.98%. Facts fully prove that the effectiveness of the proposed method is solidly established.
Yang, Lixin, Guo, Lidong, Xu, Liang
SAE TOMORROW TODAY - How Aerospace Safety Standards Enable the Future of Flight135808/12/2026
Whether it's supersonic travel, commercial space, or AI-enabled aircraft, one message remains constant: safety standards are the common language that enable the future of flight. Listen in as we sit down with Craig McMillan, Model Based Systems Engineering (MBSE) Growth Leader at GE Aerospace, to discuss the intersection of AI, digital engineering, and the growing complexity of modern aircraft. The conversation examines why independent verification, rigorous systems engineering, and collaboration across the aerospace industry remain essential as aircraft become more software-driven and interconnected. We'd love to hear from you! Share your comments, questions and ideas for future topics and guests to podcast@sae.org. Don't forget to take a moment to follow SAE Tomorrow Today--a podcast where we discuss emerging technology and trends in mobility with the leaders, innovators and strategists making it all happen--and give us a review on your preferred podcasting platform. Follow SAE on LinkedIn, Instagram, Facebook, X, and YouTube. Follow host Grayson Brulte on LinkedIn, X, and Instagram.
Patterson, Lori
Dynamic Response Analysis of RV Reducers with Time-Varying Stiffness2026-99-09088/7/2026
As a high-precision transmission core component, the RV reducer’s performance depends on the time-varying stiffness of its core components. Building a time-varying stiffness model is essential for studying its dynamic characteristics. This paper addresses the lack of key factors in existing dynamic studies by creating a multi-factor coupled dynamic model. It analyzes the time-varying stiffness of the crankshaft bearing, involute gear, and cycloid gear-pin gear. The study also focuses on building a dynamic analysis model for the crankshaft bearing. By measuring changes in oil film thickness and initial assembly clearance caused by temperature rise, it explains how combined clearance affects bearing performance. To verify the model, a domestic RV reducer is modeled and assembled in SolidWorks. The simplified model is imported into ADAMS for simulation. Under set load and speed conditions, dynamic parameters like angular velocity and acceleration of core components are obtained. This provides a more scientific analysis method and data support for understanding the dynamic characteristics and improving the transmission performance of RV reducers.
Xuan, Liang, Teng, Shaowei, Huang, Ruizhe, Wan, Zefu, Shao, Mengqi, Yu, Zhishen, Wang, Ziyue
Research on the Cumulative Damage Mechanism of Special Equipment Steel Structures Based on Complex Load2026-99-10118/7/2026
Steel structures subjected to complex loading conditions undergo various types of damage, including fatigue, crack propagation, plastic deformation, and corrosion. As time and loads accumulate, these damages may lead to structural failure. The investigation of the damage mechanisms and constitutive models for special equipment steel structures under complex loading has been a significant challenge in engineering. This study develops a constitutive model for steel structure damage under static and dynamic loads, as well as vibration disturbances, through a normalization approach. The proposed model is validated via simulation to assess its feasibility. The findings offer a theoretical foundation for the design, life prediction, and health monitoring of steel structures in special equipment, aiming to enhance their safety and reliability. This research provides critical insights into damage analysis, failure prediction, and the optimization of repair strategies for steel structures, with significant practical implications in engineering applications.
Wang, Jun, Yu, Zhen, Huang, Yong-qiang, Chen, Wei-bi
Molecular Dynamics Simulation of Temperature Effects on the Hot Deformation and Microstructural Evolution of Al-Mg-Si Aluminum Alloy2026-99-10108/7/2026
In this work, molecular dynamics simulations are applied to systematically examine the influence of varying temperatures (300 K, 500 K, and 700 K) on the Elevated-temperature compression behavior and micromechanical characteristics of polycrystalline Al-Mg-Si aluminum alloy. A nanopolycrystalline model was established to analyze the stress–strain response, dislocation evolution, and crystal structure changes occurring during the deformation process. The simulation results show that the yield strength and elastic modulus both decline as temperature increases, indicating a pronounced thermal softening effect. During the early stage of plastic deformation, dislocations mainly have their nucleation sites at grain boundaries and then propagate into the grain interiors, where they form interconnected networks along with stacking faults and twin structures. This work reveals the thermal deformation mechanisms of Al-Mg-Si aluminum alloy at the atomic scale and provides theoretical guidance for the optimization of its hot-working processes.
Sun, Ruifeng, Liu, Shoukui, Wang, Rui, Sun, Xuemei, Ding, Shuli, Ma, Xiaofei
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
Research on Ventilation Performance of Slotted Honeycomb Panels for Civil aircraft2026-99-09138/7/2026
Auxiliary fuel tank systems for civil aircraft are typically employed in extended-range aircraft. As a critical structure for fuel storage, the structural safety of auxiliary fuel tanks directly impacts aircraft safety. Such tanks are generally constructed from honeycomb sandwich composite panels. Owing to their outstanding advantages, including high specific strength, light weight, and corrosion resistance, honeycomb sandwich composite panels have become the material of choice for civil aircraft fuel tanks. However, to meet the safety requirements for ventilation and leakage drainage in the sandwich structure of fuel tanks, dedicated flow channels must be created by slotting inside the honeycomb composite panels to ensure timely discharge of fuel vapor and accumulated fluid from the tank sandwich. Conventional flow channels are symmetrically arranged on the end faces of the honeycomb core, making it difficult for ventilation airflow to penetrate the center of honeycomb cells. This results in ventilation and drainage blind spots within the cells, which tend to cause accumulation of fuel vapor and residual fluid over prolonged service. Consequently, the aging of the core layer is accelerated, compromising the structural integrity of the composite panel and the service life of the fuel tank. This paper proposes an asymmetric ventilation flow channel design. By optimizing the slotting position, size, and distribution pattern of the flow channels, the limitations of the traditional symmetric layout are overcome. To accurately investigate the effect of this design on the internal ventilation performance of honeycomb composite panels, a three-dimensional flow field model of the honeycomb sandwich composite panel is established using computational fluid dynamics (CFD). The ventilation airflow distribution, velocity, and flow rate characteristics under different flow channel designs are simulated and compared with those of the conventional symmetric flow channel design. The results demonstrate that the asymmetric ventilation flow channel design improves the ventilation uniformity inside the honeycomb cells and completely eliminates the ventilation and drainage blind spots at the cell center inherent in the traditional design. Meanwhile, the design significantly enhances the ventilation gas velocity and flow rate at the center of honeycomb cells, accelerating the discharge of fuel vapor and drainage of accumulated fluid. The overall ventilation efficiency is considerably higher than that of the traditional symmetric design. This study provides a theoretical basis and technical support for the safety design of honeycomb composite panels used in auxiliary fuel tanks of civil aircraft.
Yao, Lijun, Chen, Jun
Accelerometer Mass Compensation on Frequency Response Functions in Impact Testing Based on the Substructure Method2026-99-09118/7/2026
Impact testing utilizing instrumented hammers and accelerometers is a widely adopted technique in dynamic testing. The mass loading effect of the accelerometer alters the dynamic response of the test structure, leading to deviations between the measured frequency response functions (FRFs) and their true values. Furthermore, the effects on the FRFs are contingent upon the positioning of the accelerometer, thereby causing the measured FRFs between two points to fail to meet the principle of reciprocity. This paper investigates the compensation method for the mass of a single accelerometer in impact testing. Compensation formulas for both origin–FRF and cross–FRF are derived using the frequency domain substructure decoupling method. Numerical simulations on a cantilever beam and experimental tests with milling tools validate the proposed methodology. The compensation formulas for FRFs presented in this paper are expected to enhance the measurement accuracy of FRFs in modal testing of small structures, particularly relevant for lightweight components in aerospace, aircraft, and transportation systems, where precise dynamic characterization is critical.
Tang, Zhenrong, Yao, Zhenqiang
Mechanical Structure Design and Dynamics Simulation of an Exoskeleton Leg Rehabilitation Robot2026-99-09028/7/2026
In response to the challenges of training and rehabilitation for patients with leg dysfunction, this research focuses on two core requirements: “bionic adaptation” and “safety assistance”. It introduces a novel exoskeleton leg rehabilitation robot designed to support diverse rehabilitation exercises for individuals with leg disabilities during therapy. The robot system consists of a lumbar support structure, thigh mechanical components, calf mechanical components, leg fixation straps, and foot mechanical structures, and achieves multi degree of freedom motion simulation through three main joints: hip joint, knee joint, and ankle joint. Each mechanical leg has three independent degrees of freedom, which can effectively simulate the natural movements of the human lower limb, such as flexion, extension, abduction, etc., during the gait cycle, thus meeting the functional needs of patients for different movement modes during rehabilitation training. On the basis of structural design, this study further utilizes multi-body dynamics simulation software ADAMS to conduct kinematic and dynamic analysis of the exoskeleton robot. By simulating the joint torque of the exoskeleton legs under ideal working conditions, the rationality and smoothness of the mechanism design are verified. The simulation results not only reflect the performance of the robot in typical rehabilitation actions, but also provide a theoretical basis and data support for the selection and parameter matching of key execution components (such as servo motors, reducers, etc.), laying an important foundation for the physical development and control strategy optimization of the robot system.
Mu, Xiaoqi, Ma, Chao, Li, Weijie, Pu, Shuai, Liu, Jiaqi, Wang, Ruiyin, Zhang, Xiaodong
A Foundational CFD Validation for an Occupant-Centric HVAC Digital Twin: Paving the Way for Real-Time Control2026-99-10028/7/2026
The heating, ventilation, and air-conditioning (HVAC) systems are one of the main factors that contribute to the building’s energy usage. Achieving an effective balance between reducing energy use and maintaining acceptable thermal comfort is the key challenge in conventional HVAC systems. To overcome this challenge, integrating the occupant-centric controls coupled with digital twins into HVAC systems is another potential technique for this effective balance. For this purpose, computational fluid dynamics (CFD) offers the potential, in combination with other surrogate models for real- time applications to enhance the system's performance further. In general, the CFD is applied to investigate indoor airflow/temperature distributions. These are essential for occupant health, comfort, and energy optimisation for the HVAC design state. The objective of this study is to propose an initial step toward building an occupant-centric HVAC digital twin by validating a CFD model of an office against dense in-situ sensing data. The model has been used to resolve airflow and temperature stratification under conventional HVAC operations, using ANSYS Fluent. The boundary conditions have been derived from measured supply parameters, internal gains, and local weather conditions. The results from this study show that the air velocity and temperature at selected durations follow the same trend with low errors, compared to the sensing and measurement data. The model validation from this study establishes the basis for a weather- aware, occupant-feedback digital twin for larger floorplates and multi-zone systems. To achieve the target of the energy and comfort co-optimisation in Industry 4.0-ready buildings, the future work will focus on surrogate modelling to enable near-real-time inference for closed-loop occupant-centric controls, which will directly support dynamic set-point adjustments and multi-zone system ventilation.
Larpruenrudee, Puchanee, Hellany, Ali, Famakinwa, Tosin, Shrestha, Surendra, Attwater, Roger, Calheiros, Rodrigo Neves
Research on Corrosion and Friction Behaviors of 8Cr4Mo4V Bearing Steels in Corrosive Medium Environments2026-99-10068/7/2026
Corrosion-wear damage behavior affects the bearing life and reliability seriously in a corrosive environment. The accurate evaluation of the tribocorrosion behavior of 8Cr4Mo4V bearing steel samples is critical for the application and protection of bearings. The present work seeks to establish the relationship between laboratory salt spray accelerated experiments and the corrosion of 8Cr4Mo4V steel samples in real outdoor marine atmosphere exposure, and investigate the tribological behavior in the corrosion-wear process under artificial seawater. Results show that salt spray corrosion tests can well simulate the corrosion of 8Cr4Mo4V steels in marine atmospheric exposure. The tribocorrosion performance of 8Cr4Mo4V steels under artificial seawater conditions is affected by the temperature effect of the corrosive liquid and the working conditions. Increased normal load and reduced rotational speed can improve the anti-friction performance. This work offers the possibility and reference of precise control of corrosion-wear-coupled damage failures for bearings.
Zhao, Chao, Ying, Lixia, Nie, Chongyang, Zhu, Tianlin, Sun, Dong
Unlocking Simulation Study of Convection Heat Transfer Magnesium Strip Solid Spring Mechanism2026-99-10098/7/2026
This study investigates the convective heat transfer mechanism in the unlocking process of magnesium strip-based solid propellant mechanisms, supported by numerical simulations. Through developing a multiphysics coupled model for the unlocking mechanism, we analyze magnesium strip fracture and unlocking processes, revealing how convective heat transfer affects unlocking duration. The simulation results demonstrate excellent agreement with experimental data, providing theoretical guidance for engineering design of magnesium strip-based solid propellant systems.
Wang, Haoxu, Zhong, Jianlin
Study on Visible-Light-Driven Photocatalytic Degradation of Tetracycline Hydrochloride by g-C 3 N 4 /CoFe 2 O 4 Composite Photocatalysts2026-99-10078/7/2026
g-C₃N₄, a metal-free semiconductor photocatalyst, demonstrates remarkable potential, but its practical application in pollutant degradation is significantly limited by the rapid recombination of photogenerated electron-hole pairs and low photocatalytic efficiency. To address this, a series of magnetic recyclable g-C₃N₄/CoFe₂O₄ composite photocatalysts with different CoFe₂O₄ doping ratios were innovatively designed and prepared via thermal polymerization, sol- gel, and combined with ultrasonic and heat treatment processes. The novelty of this composite design lies in the effective integration of magnetic CoFe₂O₄ with g-C₃N₄ through a heterojunction structure. It substantially boosts the absorption of visible light. Concurrently, it effectively fosters the separation and mobility of photo-induced charge carriers. The composite materials were systematically characterized by X-ray diffraction, thermogravimetric analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, photoluminescence spectroscopy, and ultraviolet-visible diffuse reflectance spectroscopy. Using tetracycline hydrochloride as the target pollutant, the photocatalytic activity of the composites was evaluated under visible light irradiation, and the effects of initial concentration, catalyst dosage, and the influence of solution pH on degradation efficiency were also examined. The results indicated that the composite with a CoFe₂O₄ to g-C₃N₄ mass ratio of 1:3 (denoted as 3-CN/CFO) exhibited the optimal performance: a TCH degradation rate of 80.29 % within 105 minutes and a total organic carbon removal rate of 61.63 %. After five consecutive cycling experiments, the degradation efficiency remained above 70 %, demonstrating good reusability and stability. The performance improvement is attributed to the formation of heterojunctions in the composite, which effectively facilitates charge separation, inhibits carrier recombination, and enhances visible light absorption. Furthermore, the inherent magnetism of the composite permits efficient recovery, streamlining its integration into practical applications. Toward the purification of antibiotic-contaminated water, this research proposes a viable method for fabricating highly effective and recyclable photocatalysts.
Hua, Longjun, Chai, Tian, Wang, Yiming, Zhang, Jing, He, Ting
Simulation Study on the Equilibrium Strategy and Thermal Runaway Suppression of Lithium Iron Phosphate Module Based on SOC Inconsistency Regulation2026-99-10138/7/2026
With the rapid development of the new energy vehicle energy storage industry, lithium-ion battery technology is undergoing a phase of rapid technological advancement. Enhancing battery energy density and safety remains a core challenge in overcoming industrial bottlenecks. During long-term cycling operations, deviations in state of charge (SOC), voltage, and temperature of individual cells inevitably occur, leading to reduced energy utilization efficiency. These deviations may also induce local overcharging and internal short circuits in individual cells, ultimately triggering thermal runaway incidents. While existing battery balancing strategies primarily focus on uniformity regulation, they fail to adequately address the coupling mechanisms of heat generation, heat storage, and thermal runaway propagation during balancing processes. Furthermore, the poor coordination between these strategies and thermal management systems makes it difficult to meet the complex safety requirements of high-energy-density batteries. To enhance the safety and energy utilization efficiency of battery systems during operation, this study focuses on the synergistic optimization of balancing strategies and thermal runaway prevention control. By establishing computer models of individual cells and battery packs in CATIA software, the research analyzes the evolution mechanisms of thermal runaway triggered by system state inconsistencies, while exploring the regulatory patterns of balancing parameters on thermal safety. Utilizing the ANSYS simulation platform, the study systematically examines the impact of three critical parameters—ambient temperature, discharge rate, and coolant flow rate—on battery temperature rise, providing theoretical support and technical references for the design of high-reliability lithium-ion battery pack systems.
Yu, Zheng, Gong, Ji, Fan, Yi, Liang, Wei, Li, Yuewei, Liu, Fashen, Xie, Maojun, Cen, Zucai
Structural Optimization Design and Experimental Study of a Shipboard Cabinet2026-99-09018/7/2026
The shipboard cabinet is an important carrier of radar equipment. It is necessary to ensure a good working environment and provide maximum support and protection for the internal equipment. In this paper, a shipboard cabinet that can realize a parallel heat dissipation architecture was taken as the object. The natural frequency and mode were used to find the area where the cabinet was prone to high-frequency vibration under impact excitation. The response characteristics of the cabinet under strong impact conditions were studied using a nonlinear transient dynamic analysis method. The weak links in the cabinet structure were identified, and the structural reinforcement design was carried out. After optimization, the maximum stress value of the cabinet was significantly reduced, and the safety factor was greater than 1.5. Finally, the effectiveness of the structural optimization was verified through experiments. The cabinet vibration isolation system was optimized and selected to ensure that it has good vibration isolation characteristics and impact response. The vibration isolation performance of the wire mesh isolator and the non-resonant peak isolator in the shipboard vibration and impact environment was verified by experiments. The impact transmissibility is less than 0.3, and the vibration transmissibility is less than 1.5, which can further improve the vibration and impact resistance of the shipboard cabinet.
Ni, Xiaokang, Jiang, Bo, Zhang, Liangjuan, Wu, Jingkai
Analysis of Annular Pressure Drop Resistance across Tubing Joints Based on CFD and Nonlinear Fitting2026-99-09098/7/2026
During well testing and killing operations, tubing couplings with a larger diameter than the tubing body significantly increase the flow friction in the casing-tubing annulus, alter the rheological behavior of the kill fluid, thereby affecting operational accuracy and even leading to operational failure in severe cases. Most existing relevant studies focus on the impact of changes in flow area on flow, but ignore the effect of the coupling’s own structural configuration. Moreover, the research conclusions lack verification by downhole measured data, and there is an urgent need to further improve the analysis accuracy. Taking an ultra-deep well in the Xinjiang Oilfield as the engineering background, this paper conducts targeted research: first, a physical model of the flow field in the casing-tubing annulus passing through the tubing coupling is established, and a method for judging and determining the rheological properties of the kill fluid based on the fitting of the physical model and key parameters is proposed; on this basis, a numerical model including the coupling’s structural configuration is established and solved, and the friction calculation equation for the casing-tubing annulus passing through the tubing coupling is obtained through nonlinear fitting; finally, the calculation results of this equation are compared and verified with the measured data and numerical simulation results. The research results show that: under six working conditions, the flow characteristics of the kill fluid all conform to the characteristics of Bingham fluid, which is also consistent with the general flow regime of kill fluid flow; comparing the numerical analysis results of the target well in the Xinjiang Oilfield with the calculation results of the fitting equation, the maximum error, minimum error, and average error of friction analysis under the six working conditions are 14.46%, 0.39%, and 6.15% respectively; the total friction of the casing-tubing annulus in the entire well section calculated based on the theoretical equation is 12.085 MPa, and the relative error compared with the field measured 13 MPa is 7.57%, which meets the engineering accuracy requirements. The equation proposed in this study provides a universal equation for predicting the pressure drop of non-uniform flow in the wellbore, and also has an important reference value for predicting the wellbore pressure in drilling and oil-gas production operations.
Song, Zhitong, Jiang, Wu, Mi, Hongxue, Cao, Yinping, Dou, Yihua
Research on the Influencing Factors of e-Cigarette Atomization Temperature2026-99-09038/7/2026
This study aims to thoroughly explore the key influencing factors of e-cigarette atomization temperature to provide a scientific basis for e-cigarette product development and avoid the harmful substance release caused by excessively high atomization temperature. The fourth-generation e-cigarette was selected as the research object, and the atomization temperature was measured using a method based on the TCR (Temperature Coefficient of Resistance) to systematically investigate the effects of puff topographies (puff volume, puff interval, and puff duration), working parameters (output power and draw resistance), and solvent ratios on atomization temperature. The results show that solvent ratio, puff duration, power, puff interval (P<0.01), and puff volume (P<0.05) are significant influencing factors of atomization temperature. Puff duration and output power have positive correlations with atomization temperature, while puff volume, puff interval, and draw resistance have negative correlations. Regarding the solvent ratio, the atomization temperature generally increases with the increase of VG mass fraction in the e-liquid. This study proposes a novel method for measuring the atomization temperature and clarifies the influence of various factors on e-cigarette atomization temperature, analyzes the principles and degrees of influence, and provides theoretical support for optimizing e-cigarette design and reducing the health risks associated with excessively high atomization temperature, which is of great significance to the healthy development of the e-cigarette industry.
Xu, Yupeng, Zhou, Mingzhu, Hao, Dong, Li, Xiaohui, Wang, Jinping, Zhou, Decheng, Xing, Jun
Design of a Biomimetic Spherical-End Tool Based on Gastropod-Shell Surface Microstructures and an Investigation of its Polishing Performance2026-99-10018/7/2026
To improve stress-distribution uniformity and reduce wear during polishing, a biomimetic flexible polishing tool was developed by incorporating microstructured surface features inspired by the gastropod shell. A biomimetic flexible polishing tool was first geometrically modeled, and then the tool–workpiece contact was analyzed in the elastic polishing regime using Preston’s material removal equation to elucidate stress transmission and contact deformation mechanisms. An Abaqus finite-element model of the elastic tool–workpiece contact was subsequently established to compute tool and workpiece stress fields and contact-area fraction during polishing. The biomimetic tools were fabricated by curing silicone rubber mixed with carbon nanotubes. Polishing validation was performed on a small CNC platform using quartz glass under the parameters α=15°, ap=2mm, and w=30r/s. Results indicate that the biomimetic tool incorporating gastropod-shell microstructures increases the machining contact area by up to 48.60% relative to a conventional tool, and after t=30 min of polishing the surface roughness Ra decreased from 1.019μm to 76nm. These outcomes demonstrate that the biomimetic microstructured flexible tool effectively improves contact stress uniformity and enhances surface- processing accuracy for quartz glass.
Song, Jintao, Hui, Jizhuang, Guo, Lei, Xu, Chen, Hei, Zhengqiang, Zhong, Taiyang, Wang, Jiawei, Liu, Jin
Research on the Operating Characteristics of a Micro Turbine-Based Emergency Device2026-99-09128/7/2026
To meet the power and electricity supply demands in special scenarios such as fire safety rescue, mine refuge chambers, and explosion-proof and dust-proof environments, a portable emergency rescue device powered by compressed air and driven by a two-stage axial-flow micro-pneumatic turbine is proposed. The pressure and velocity fields of the pneumatic turbine were analyzed using a combination of numerical analysis and experiments. The effects of nozzle number and inlet pressure on the operational characteristics of the turbine and the emergency device were compared. The results show that the maximum ratio of the output torque of rotor 2 to rotor 1 is 12%. The output power of rotor 2 is less than that of rotor 1, with the maximum output power of rotor 2 being 16.5% of rotor 1. The two-stage rotor structure helps to reduce residual speed loss. At the same rotational speed, increasing the inlet pressure of the turbine can enhance its output power. At an inlet pressure of 300 kPa and a rotational speed of 30, 000 rpm, the aerodynamic turbine torque is 13.8 N·m, and the turbine reaches an output power of 42 W. The emergency device, operating in a triple-nozzle mode, shows higher power and efficiency compared to the two-nozzle mode, demonstrating a higher power and efficiency than that observed in a two-nozzle mode. The maximum power output is 28.1 W, with the highest efficiency reaching 24.87%.
Liu, Jiang, Wu, Xi, Gao, Zhiwei, Chen, Bin, Ma, Renjun
Experimental Study on the Combined Effects of Swirl and Inlet Offset on the Flow through an Automotive Catalyst Monolith Substrate03-19-04-00198/7/2026
Maldistributed flow within an automotive catalyst can cause reduced conversion efficiency, high pressure loss, and premature deactivation. However, packaging constraints often result in uneven flow distribution between the monolith channels, thus compromising design and, inevitably, performance of the device. Flow uniformity may be improved by the introduction of swirl upstream of the catalyst assembly, and in turbocharged applications the residual swirl from the turbine can serve that purpose. Indeed, low swirl has been shown to provide favorable flow uniformity in the monolith substrate in an axisymmetric flow setup. However, the automotive exhaust aftertreatment setups are seldom axisymmetric, and the combined effects of inlet swirl and offset on the flow profile through a monolith substrate are unknown. To address this gap, this study provides the first systematic experimental characterization of the coupled influence of inlet swirl and packaging-relevant inlet offset on flow development and uniformity in a sudden expansion catalyst assembly. Particle image velocimetry (PIV), wall pressure measurements, and hot-wire anemometry (HWA) are combined to link the upstream separation and recirculation structures to the velocity distribution downstream of the monolith. The results reveal a previously unreported swirl-dependent sensitivity to geometric asymmetry: under no-swirl and moderate-swirl conditions, flow uniformity is robust to inlet offset, varying by no more than 1.4%, whereas at low swirl the offset reduces uniformity by up to 8% at high mass flow rate. Increasing mass flow rate reduces uniformity by up to 15%, while swirl improves uniformity by up to 19% relative to axial flow. These findings demonstrate that improvements observed for swirl in axisymmetric assemblies cannot be assumed to transfer directly to offset geometries. Swirl intensity and inlet alignment must instead be considered as coupled design variables. The measurements also provide a benchmark dataset for validating computational fluid dynamics simulations before their application to production-type systems.
Rusli, Ijhar, Aleksandrova, Svetlana, Medina, Humberto, Benjamin, Stephen F.
Time-of-Flight Estimation Using the Discrete Logarithmic Frequency Method2026-01-50458/6/2026
Conventional measurement instruments such as scales, thermocouples, and laser-based technologies present challenges when used on lengthy and winding underground pipelines. These methods are often not feasible because of physical constraints, the challenge of light traveling in curves, and the need for large, energy-intensive sensors. Ultrasonic and microwave techniques both face challenges in making long-distance measurements because of rapid signal weakening and high energy requirements, which make them impractical for small pipes. This study introduces an original technique for Time-of-Flight (ToF) estimation using the Discrete Logarithmic Frequency (DLF) method to address these limitations. By analyzing the time–frequency correlations of signals transmitted through channels, the proposed technique enhances the precision and dependability of ToF measurements. By employing the DLF method, we are able to effectively gather and assess the signal’s performance as conduit lengths vary.
Chinni, Venkata Sai Sandeep, Balasubramanian, Prabakaran, Mamat, Rizalman, Yasin, Mohd
Analysis of the Impact on Ride Comfort from Splitting the Unsprung Mass in Vehicle Modeling2026-01-50578/6/2026
The study was conducted to investigate the differences in ride comfort analysis between treating the unsprung mass as a whole and modeling it separately. A classical two-degrees-of-freedom single-wheel vehicle vibration model and a three-degrees-of-freedom single-wheel vehicle vibration model with split unsprung mass were established, with their state-space descriptions determined. The fundamental vibration response quantities of both models were identified, and time-domain simulations under random road excitation were performed using MATLAB/Simulink. The results indicate that the two modeling approaches exhibit minimal differences in ride comfort analysis for the sprung mass, but there are certain differences for the unsprung mass. Additionally, for the three-degrees-of-freedom single-wheel vehicle vibration model with split unsprung mass, the axle-to-wheel mass ratio was introduced to analyze the changes in the fundamental vibration response quantities when the unsprung mass increases by a fixed value and is distributed differently between the axle and the wheel. The results show that variations in the axle-to-wheel mass ratio have no significant impact on the vibration characteristics of the sprung mass. Reducing the mass ratio, i.e., transferring part of the unsprung mass to the wheel, can somewhat reduce the vertical acceleration of the unsprung mass, but it will slightly increase the relative dynamic load on the wheel. Finally, the other two models were simplified by combining the two masses connected by the bearings.
Jie, Li, Wei, Deng, Chengyu, Li
Analysis and Elimination of Transient Impact of Rollers in S-cam Brakes2026-01-50668/5/2026
S-cam brake is a drum-type foundation brake used in heavy commercial vehicles. It is a safety-critical device; hence, thorough validation of its performance by lab test rigs and field tests is essential. During prototype testing, an unusual impact was observed during dynamic braking at high pressure application, specifically when the brake drum is rotating, after a period of operation of about 10,000 cycles. This phenomenon was then observed even at static braking when the brake drum was at rest. From initial inspection, it is due to the cam roller, which rides on the web-slot provided at the shoe assembly, while the S-cam is rotating and falls back instantly. This phenomenon occurs repeatedly and creates an audible noise, which needs to be eliminated. The study aims to correlate the phenomenon using finite element analysis (FEA) as in a prototype test and to identify the root cause and optimize the design variables. Since the friction coefficient at the cam roller–web interface is unknown after a period of operation, different values of friction coefficient, ranging from 0.1 to 0.8, are iterated and simulated by rotating the S-cam until the braking effort is reached. The dynamic implicit analysis procedure in Abaqus standard is used to simulate this condition. Based on the results, design variables were improved to mitigate the issue. A quick solution, achieved by modifying a minor feature, successfully prevented the fallback behavior and was validated through physical testing. Furthermore, a permanent solution was developed to eliminate both the “ride-on” and “fallback” phenomena by optimizing component dimensions. This FEA methodology helps to validate the design in an initial concept phase itself for future variants. Using this method, even the structural and fatigue performance of braking parts can be validated at a system-level simulation with better accuracy.
Dinesh Kumar, J., Riyaz Mohamed, D., Vasanth Bharath, S., Rajkumar, S., Murugan, S.
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