Browse Topic: Bodies and Structures

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Relevant vehicle front-end components for pedestrian laboratory testing to address real-world pedestrian injuries when struck by passenger vehicles with high hood heights2026-22-00098/14/2026
In the United States, pedestrian deaths account for 18% of roadway fatalities and have increased 78% since their lowest point in 2009. U.S. consumers are increasingly purchasing larger vehicles that are responsible for a disproportionate number of pedestrian injuries. This study examined a dataset of pedestrians struck by passenger vehicles in Michigan from 2015 to 2024 to identify the unique characteristics of the tallest vehicles, large SUVs and pickups, which are contributing to increased injury. Vehicle height was categorized as the hood leading edge (HLE) height compared with the estimated pedestrian hip and waist heights from anthropometric measures. Maximum abbreviated injury scale and injury sources by body region were tabulated for three vehicle height categories. Typical kinematic patterns were observed for each relative height category and the corresponding injury frequency and impact locations. For vehicles with high hood heights, head and torso injuries were commonly from the front of the vehicle —the grille, headlights, and HLE. In contrast, head injuries sustained when pedestrians were struck by medium-height and short vehicles were primarily from the vehicle hood and windshields. Even among the tallest vehicles where the bumper was much higher than the pedestrian’s knee, leg injuries from the vehicle bumper and valance were frequent, suggesting that evaluating these vehicle components is also necessary to address lower extremity injuries. This study identified the unique pedestrian impact locations associated with the tallest vehicles, which can help guide vehicle designers when considering impact attenuation strategies to reduce injury in crashes with pedestrians.
Mueller, Becky, Jermakian, Jessica
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
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 Study of the Landing Gear Door Assembly Unit for the Aircraft2026-99-03408/14/2026
Against the backdrop of the rapidly developing aviation manufacturing industry, there is an increasingly urgent demand for the high-volume and high-quality delivery of aircraft landing gear doors, which are critical components for ensuring flight safety. Traditional assembly methods face numerous bottlenecks, making it difficult to meet the industry’s evolving requirements. Consequently, a design study has been conducted on the assembly units for aircraft landing gear. By analyzing the structural characteristics and assembly process flow of the landing gear doors, the assembly procedures were optimized and reorganized. A pulsatile assembly unit incorporating dual-attitude modular assembly devices, an automatic transportation system, curing devices with heating, and module storage facilities was designed. Digital simulation technology was employed to perform a simulation analysis of the assembly process, verifying the feasibility of the proposed scheme. This production addressed issues such as long curing cycles for liquid gaskets, low efficiency in layered hole-making, and difficulties in transporting modular fixtures. It achieved semi-automation and intelligence in the assembly, curing, and transportation processes of landing gear doors. Compared to the production mode during the development phase, the production cycle for individual products was reduced by 50%, and annual delivery capacity increased by 100%. The research findings provide effective technical support for achieving efficient and high-quality assembly of aircraft landing gear doors.
Bo, Donghai, Gao, Chunlin, Zhou, Houchao, Chen, Yilong
Review of Semi-Active Shock Absorption Mechanisms in Landing Systems01-19-02-00068/13/2026
Effective shock absorption is essential for maintaining stability during landing events. Aerospace systems traditionally rely on oleo-pneumatic struts, while robotic platforms utilize lightweight compliant joints for impact mitigation. Recent advances have shifted attention toward adaptive solutions, including magnetorheological and electrorheological dampers, which can adjust their damping characteristics in real time through sensor feedback and control algorithms. By integrating established mechanical design principles with advanced materials and intelligent control strategies, modern landing systems can achieve improved energy dissipation and enhanced performance under variable and unpredictable conditions. This work evaluates the transition from passive to adaptive shock absorption technologies by examining landing dynamics, the mechanical architectures of conventional and semi-active systems, and the control strategies that enable adaptive damping. The findings indicate that, although passive systems offer reliability and simplicity, they lack the adaptability required for highly variable environments, while semi-active systems provide enhanced performance through real-time modulation enabled by advanced control algorithms. However, challenges related to power requirements, system complexity, material durability, and long-term reliability continue to limit widespread implementation of adaptive technologies. Overall, this review highlights the limitations of passive designs, evaluates the tradeoffs between MR and ER damping technologies, examines the evolution of semi-active control strategies, and identifies the key technical barriers that must be addressed before adaptive shock absorption systems achieve broader operational adoption.
Shah, Rajesh, Patel, Parth, Mittal, Vikram
Airplane Design and Test Considerations for Tire Spray SuppressionARP1904 (Current)8/10/2026
This SAE Aerospace Recommended Practice (ARP) relates considerations and recommendations for design test procedures and test data evaluation for qualification of tire spray deflection devices.
A-5 Aerospace Landing Gear Systems Committee
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
Experimental and Mechanistic Study on Current Carrying Friction of Sliding Ring Slide in Shaft-Type Oil Distributor under Different Oil Environments2026-99-10058/7/2026
The issue of current-carrying friction wear in the sliding ring slider of a controllable pitch propeller (CPP) oil distributor under shaft current conditions was addressed through the development of a specialized wear test device. Comparative tests were carried out with and without the application of electrical current in order to assess lubrication performance in bio-oil, mineral oil, and gear oil. Under conditions of low electrical current, the device exhibited significant signs of current-induced friction wear, in addition to substantial oil oxidation and the accumulation of deposits within the bio-oil. Conversely, the level of wear experienced was minimal in both mineral oil and gear oil conditions. These results imply that CPP systems utilising bio-oil encounter a considerable risk of wear under current-carrying circumstances. Quantitative analysis revealed that the wear depth of the friction pair in bio-oil under energized conditions reached 0.02 mm, accompanied by the formation of a phase-transformed layer up to 11.2 μm thick, which was approximately twice that observed in mineral or gear oils. Metallographic evidence confirmed severe arc erosion as the dominant wear mechanism, which was significantly exacerbated by the inferior oxidation stability and higher electrical conductivity of the bio-oil. In engineering practice, the utilisation of alternative lubricants is to be given precedence, and the shaft-type oil distributor is to be electrically insulated.
Xia, Miao, Li, Jiyue, Chang, Long, Wu, Rongjia
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
683 Guidance for Electronic Shop Reports in Aviation MaintenanceARINC683 (Current)8/4/2026
The purpose of this standard is to provide guidance for the content, format and two-way electronic exchange of data between a Service Provider and the Customer. The standard is focused on the production of an electronic Shop Findings Report by the Service Provider, and to promote automated electronic data exchange.
Aviation Maintenance Committee
Simulation of Compression and Bending Performance of GFRP Rod of Composite Hollow Post Insulator2026-99-01077/31/2026
Composite hollow core station post insulators utilize fiber-reinforced epoxy resin as the core rod material, offering advantages such as high specific strength, high specific stiffness, and excellent fatigue resistance. This enables them to effectively meet the flexible, variable, and complex operational demands of modern power systems. However, composite materials exhibit anisotropic characteristics, resulting in complex mechanical properties. Additionally, the core rod of hollow pillar composite insulators is typically fabricated through a spiral-plus-circumferential winding process, which significantly complicates structural design and computational analysis. This study establishes a finite element model of the hollow pillar composite insulator core rod in ABAQUS. It analyzes the influence of fiber content on composite material parameters and performs finite element numerical calculations to examine the stress state of core rods with different winding angles under compressive and bending loads. The research findings provide theoretical support for the optimized structural design of hollow pillar composite insulator core rods.
Liu, Jianbiao, Du, Yijun, Quan, Xiaoxi, Zhou, Songsong
Research on Failure Analysis of Aircraft Windshield Outer Layer Fracture Caused by Arc Fault2026-99-01287/31/2026
The malfunction of the aircraft windshield electric heating system, particularly arc discharge, poses a serious threat to flight safety by causing glass breakage. A systematic study was conducted on the causes and effects of arc faults on windshield structural integrity, employing macroscopic observation, microscopic analysis, and energy dispersive spectroscopy (EDS) following a windshield fracture incident. The results indicate that arc discharge typically occurs at the interface between the heating film busbar and adjacent structures. Localized high temperatures cause the outer glass to fracture, generating radial cracks. The ablation of the busbar silver coating and the carbonization of the PVB interlayer are direct evidence of arc action, whereas the heating wire remains a passive component affected by the high-temperature environment. The fault is primarily attributed to local disbonding at the busbar interface and moisture ingress. Based on the findings, recommendations are proposed for process optimization and inspection method improvement, providing a basis for the safe design and maintenance of windshield structures.
Chen, Li, Feng, Yanpeng, Ding, Keqin
Design and Optimization of an External Rotor Permanent Magnet Motor with a Three-Segment Non-Uniform Halbach Array2026-99-01537/31/2026
To further enhance the performance of the drive unit motor, a novel three-segment non-uniform Halbach array magnetic pole structure is proposed, which is applied to an external rotor permanent magnet motor with magnetic pole optimization. First, the overall motor design is carried out according to the requirements, determining the fundamental parameters of the motor. Then, four common magnetic pole structures—conventional arc-shaped, three-segment, Halbach array, and three-segment non-uniform Halbach array—are analyzed. A finite element analysis model of the motor is established for electromagnetic analysis, comparing the air-gap flux density, torque, and torque ripple of the four magnetic pole structures. Finally, optimized parameters for the stator and rotor tooth shapes are determined, and an optimization model is established. The NSGA-II algorithm is employed to optimize the stator and rotor tooth shapes. After optimization, the motor maintains its torque output while reducing torque ripple by 50%, effectively improving its performance.
Zhao, Changle, Yang, Liu
Implementation Strategies of Requirements Engineering in Commercial Aircraft Airframe Forward Design2026-99-01837/31/2026
Focusing on the requirements engineering activities, this study analyzed the problems in the implementation process of the forward design practice of commercial aircraft airframe, introduced the breakthrough methods, including the convergence and integration with the traditional design process, the supporting work organization model, process optimization, and specification, and proposed the airframe stakeholder need capture model based on the theory of systems engineering. Practice has shown that the requirements engineering implementation strategy introduced in this paper can effectively resolve conflicts and redundancies between the requirements system and the original top-level document system requirements. It ensures clear requirements sources, sufficient basis, reasonable allocation, controllable changes, adequate change assessments, clear design status, and controllable design risks. It effectively overcomes human resource bottlenecks during the early stage of requirements engineering implementation while cultivating talent reserves for systems engineering implementation, saving approximately 23.5 person-years in labor costs. It significantly optimizes non-value-added processes, reducing approximately 100 reports. It unifies the team’s understanding of requirements work, improves coordination efficiency, and significantly improves the requirements validation rate between aircraft-level and system-level requirements by an average of approximately 46%. It assists stakeholders and engineers in systematically and scientifically capturing product requirements during the design phase, with original product design specifications covering approximately 70% of subsystem specifications on average. Given its generality across the airframe forward design domain, the airframe requirement management paradigm established by this implementation strategy holds significant importance for the comprehensive and in-depth application of systems engineering methods in commercial aircraft development.
Sun, Luyan, Chang, Liang
Measurement and Regulation of Residual Stress in Door Opening Welds of Wind Turbine Towers2026-99-01977/31/2026
Weld residual stress is a critical factor affecting the structural integrity and service life of wind turbine towers. In this study, a systematic investigation was conducted on the residual stress distribution and control methods for door corner welds of an in-service wind turbine tower after approximately 20,000 hours of operation. X-ray diffraction (XRD) measurements revealed significant tensile residual stress in the weld and heat-affected zone, with peak values reaching 315 MPa, particularly concentrated at depths of 5-7 mm. To mitigate these stresses, two post-weld treatment methods were employed: ultrasonic impact treatment (UIT) and localized heat treatment. UIT effectively transformed surface tensile stress into compressive stress, achieving a maximum compressive residual stress of -372 MPa within a depth of 3 mm, while simultaneously refining grains and increasing surface hardness. In contrast, localized heat treatment at 460 °C for 5 hours led to a broader stress relief effect, reducing residual stress by approximately 100 MPa without causing significant changes to the macrostructure, but inducing substructural rearrangements beneficial for stress relaxation. Mechanical testing confirmed that both treatments improved tensile strength, ductility, and toughness of the welds. The combined findings demonstrate that ultrasonic impact treatment is highly effective for enhancing fatigue performance at the surface, while localized heat treatment offers advantages for deep stress redistribution and long-term structural stability. This comprehensive approach provides valuable technical guidance for residual stress management in complex welded structures of wind turbine towers.
Sun, Wanting, Zhong, Zhenqian, Zhang, Bo, Liu, Hui
The Influence of Stator Vane Lean on the Rotor Blade Forced Response of an Axial Turbine2026-99-02107/31/2026
Forced response resulting from rotor-stator interaction is a primary cause of high-cycle fatigue (HCF) failure in axial turbine blades. To investigate the mitigating effect of stator vane lean on the forced response of a downstream rotor blade, this paper conducts a numerical analysis based on a fluid-structure interaction (FSI) method, comparing a baseline radial vane with a leaned vane configuration in a single-stage axial turbine. Unsteady computational fluid dynamics (CFD) was used to analyze the unsteady flow field and aerodynamic excitation, and the resulting harmonic pressures were applied to a finite element (FE) model for harmonic response analysis. The results show that, compared to the radial vane, the leaned vane design effectively weakens the potential field and wake interactions by introducing a spanwise phase difference, which significantly reduces the amplitude of the unsteady pressure fluctuations. The harmonic response analysis further validates the effectiveness of this approach, demonstrating that under the first harmonic excitation, the leaned vane configuration reduces the maximum dynamic stress on the rotor blades by 37.7%. This study confirms that stator vane lean is an effective aerodynamic detuning strategy that mitigates the excitation at its source, leading to a substantial reduction in the rotor’s dynamic stress and thus offering a valuable method for improving turbine blade reliability.
Huang, Zhi, Zhang, Ying, Xiong, Zhonggang
Study on Energy-related Mechanisms of Aeroelastic Instability of Ultra-Long Flexible Wind Turbine Blades Under Various Working Conditions2026-99-01347/31/2026
With the continuous increase in wind turbine power capacity, ultra-long flexible blades face intensified aeroelastic instability risks due to reduced structural stiffness, enhanced modal coupling, and aerodynamic nonlinearity. In addition to the analysis of basic vibration characteristics, this study focuses on energy-related mechanisms of aeroelastic instability under various working conditions. Using a numerical model integrating Dynamic Blade Element Momentum Theory (DBEMT) and Geometrically Exact Beam Theory (GEBT), over 400 time-domain simulations were conducted to characterize instability onset and development. Results reveal four distinct aeroelastic instability regions, each dominated by specific modes. In Region A, flutter dominated by the 2nd flapwise mode is observed. In Region B, flutter dominated by the 1st edgewise mode is observed. In Region C, flutter dominated by the 2nd edgewise mode is observed. While in Region D, where the medial angle of attack (AoA) of the blade has exceeded the stall angle, stall-induced vibration dominated by the 1st flapwise mode is observed. Energy analysis shows aerodynamic work concentration near the blade tip drives instability, with diverse energy exchange patterns across regions. Except for some operating conditions in region C, where instability is dominated by edgewise energy absorption, most aeroelastic instability conditions are dominated by flapwise energy absorption. Torsional degree of freedom contributes minimally to aerodynamic work, but the torsional vibration exerts a notable influence on the AoA. This, in turn, changes the comprehensive aerodynamic forces impacting the blade as well as the general aeroelastic stability. This study clarifies the relationship between operating conditions and energy-driven instability, offering some reference values for the design work and safety assurance of ultra-long flexible blades of the wind turbine.
Wang, Su, Chen, Jiajia, Zhou, Le, Shen, Xin, Li, Chun, Du, Zhaohui
Multi-Objective Topology Optimization of Wing Rib Structures for Additive Manufacturing2026-99-02287/31/2026
With the advance of high-end manufacturing and the rise of green design, lightweight structures have become a central concern in aerospace. Topology optimization offers a principled route to shed mass while preserving performance, yet most additive manufacturing (AM) studies still emphasize process tuning and new materials rather than structural layouts constrained by AM realities. This work targets a representative wing rib from a specific unmanned aerial vehicle (UAV) and formulates a multi-objective topology optimization that explicitly embeds AM constraints. Using the Solid Isotropic Material with Penalization (SIMP) variable-density framework, we couple static stiffness and strength measures with modal objectives so that the optimized rib not only resists deformation and limits stress but also improves the first three natural frequencies, thereby mitigating adverse vibration interactions at the wing level. A compromise-programming strategy balances these competing objectives under volume and manufacturability requirements, including AM-driven minimum feature scales and related geometric restrictions. Finite-element analyses are used throughout the loop to evaluate displacement, von Mises stress, and eigenfrequencies, ensuring that the emerging material distribution is both efficient and physically meaningful. The resulting topology exhibits clearer load paths and smoother stress flow, reduces peak displacements, and delivers a marked rise in the first three natural frequencies. Overall mass is lowered by approximately 55% while meeting all imposed constraints, achieving the dual aims of structural optimization and lightweighting. The study demonstrates that integrating AM constraints directly into the optimization stage yields designs that are performance-robust and fabrication-ready, and it provides a reusable workflow for thin-walled aerospace components such as wing ribs where stiffness, strength, and vibration behavior must be jointly considered.
Zhao, Fei, Zhang, Heran, Li, Xiaoting, Shi, Bowen, Kong, Xiangwei
Research on a Lightweight Door Based on an Approximate Model Constructed by a Differentiation Strategy2026-99-08127/30/2026
Taking the front door of a new energy vehicle as the research object, a finite element model was built based on HyperMesh to conduct stiffness and modal performance analysis, and clarify the characteristic differences of multiple responses of the door. To address the issue that traditional single approximation models are difficult to adapt to different response characteristics, a strategy for constructing differentiated approximation models is proposed, which is to select the optimal approximation model according to different response types. The results show that the approximation models for each response constructed based on the differentiation strategy have a fitting accuracy (R^2) of more than 0.99, close to complete fitting, which is significantly better than the overall adaptation effect of a single model. Finally, based on the approximate model established using this strategy, combined with a multi-objective optimization algorithm, the dimensions of the front door are optimized, while achieving lightweighting and performance improvement of the front door, which provides a new idea for constructing multi-response high-precision approximate models.
Wei, Yansai, Shen, Yongfeng
Adaptive Attitude Adjustment Mountain Transport Vehicle for Electric Tower Material2026-99-08507/30/2026
Transporting large steel materials for mountain electric towers is challenging due to steep gradients, narrow roadways, and uneven terrain. To address these issues, this study designs an adaptive attitude adjustment mountain transport vehicle. This mountain transport vehicle has a compact structure, measuring 1.4 meters in length and 1.1 meters in width, which enhances its suitability for confined mountainous environments. This vehicle adopts a design scheme that combines hydraulic lateral adjustment, load-bearing platform follow-up adjustment and frame adaptive adjustment mechanisms. The transportation of tower materials, measuring 12 meters in length and 1.2 tons in weight, is accomplished by employing two vehicles working in coordination. The three-dimensional model of the entire vehicle is established by using SolidWorks software. The lateral stability of the mountain vehicle and the limit working conditions of its adjustment mechanism are analyzed through theoretical calculation. The dynamic simulation of the virtual prototype is carried out using Adams software, including the processes of lateral leveling, follow-up adjustment and frame adjustment. The results show that the leveling mechanism can achieve an adjustment range of more than ±25°. The results confirm the vehicle’s excellent stability and adaptability to mountainous conditions. This study provides a more effective and more reliable solution for the construction of mountain electric towers than traditional manual or animal-powered transportation methods.
Zhang, Rui, Kong, Fanfang, He, Yuling, Lv, Jiahui, Chen, Changlong, Zhan, Lulin, Liang, Ke
Research on the Design Technology of Anti-Roll Attachment for Seaplanes2026-99-08037/30/2026
This paper takes a seaplane as the research object, based on the roll damping commonly used in the field of ships, to carry out the applicability analysis and design technology research of the roll damping for the seaplane. A T-tail configuration was selected as the attachment. The design process involved sequentially selecting the horizontal stabilizer airfoil, designing the aspect ratio parameters, and determining the strut airfoil. Consequently, two T-tail design schemes with aspect ratios of 0.76 and 1.53 were proposed. Through the hydrodynamic performance analysis of the T-tail design installed on the seaplane, the advantages and disadvantages of the two T-tail designs in the wave environment are studied. The results demonstrate that the aspect ratio of the T-tail’s horizontal stabilizer directly affects the seaplane’s wave-induced motion response. The proposed design with a larger aspect ratio of 1.53 significantly reduces wave resistance and motion response across various conditions. In the case of a relatively small aspect ratio, the maximum pitching motion is reduced by 38.4%, and the maximum heave is reduced by 59%.
Jiang, Ting, Pi, Xufeng, He, Chao, Wen, Changqing, Li, Xu
Analysis of Underbody Impact Scenarios in New Energy Vehicles2026-99-08277/30/2026
In recent years, with the rapid increase in the market penetration of new energy vehicles, safety issues in electric vehicles, particularly those characterized by thermal runaway of power batteries, especially fire incidents caused by mechanical abuse from underbody impacts, have become a major focus of industry attention and social concern. This paper systematically compiles key data from electric vehicle underbody collision incidents, covering core parameters such as impact location, geometric features of obstacles (shape and size), and vehicle speed during accidents. Based on this data, the study further reviews existing underbody scraping evaluation protocols both domestically and internationally, with a focused comparison of the differences in mechanical load and battery pack response between two typical test methods: horizontal underbody scraping and 3° inclined underbody scraping. The findings of this research aim to provide data support for the refinement of relevant evaluation standards and to offer theoretical foundations and practical references for automotive manufacturers in optimizing the design and validation strategies for underbody protection of battery packs.
Wang, Qinggui, He, Qike, Li, Wenbo, Li, Chun, Li, Xiaodong
A Standardized Mid-Fidelity Aerodynamic Comparison of Four Tiltrotor eVTOL Configurations Using SUAVE and VSPAero2026-99-08397/30/2026
This study compares 4 representative tiltrotor platforms: Joby S4, Archer Midnight, Vertical Aerospace VX4, and Uber eCRM-001 in a typical UAM mission profile under standardized rotor and wing assumptions using an integrated OpenVSP-SUAVE-VSPAero framework. This work aims to isolate the influence of eVTOL configuration from proprietary optimizations on thrust generation and aerodynamic interaction by using standard wing airfoils and a consistent rotor design tool. Vehicle geometries were modeled in OpenVSP. Rotor Operating conditions were obtained from the SUAVE conceptual design platform. Mid-fidelity aerodynamic analysis was done using VSPAero. SUAVE results show a decrease in thrust requirements as the tilt angle decreases, with the most complexity occurring in the transition phase where lift shifts from rotors to wing. Archer Midnight and Vertical Aerospace VX4 show higher hover thrust requirements due to their high takeoff weights. They display localized thrust increase near mid transition due to numerical adjustments made to achieve solver convergence. Joby S4 and Uber eCRM-001 display a smoother thrust requirement trend. VSPAero simulations also show a gradual decrease in thrust from hover to cruise. Joby S4’s continuously active rotor configuration maintained more stable performance than the hybrid configurations, which deactivate lift-only rotors after takeoff. A comparative flight feasibility analysis was conducted, defined as the difference between VSPAero-predicted thrust and SUAVE-required thrust. This analysis reveals that Joby S4 maintains a positive margin across most flight phases. Archer Midnight and Vertical Aerospace VX4 show a marginal deficit in near-cruise phases. Uber eCRM-001 showed negative margins throughout the mission, indicating limited aerodynamic robustness under standardized assumptions. Rotor-wing interactions enhances rotor thrust across all mission segments, while creating periodic pressure oscillations on the wings. Rotor-rotor interactions provide limited near-field benefits that dissipate in forward flight. The findings of this study highlight the significance of eVTOL configuration in determining performance and aerodynamic efficiency.
Sawron, Md Sadat Shahrier
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 Jamming Test Apparatus for Aircraft Cargo Door Latches2026-99-08337/30/2026
The reliability verification of cargo door latches for civil aircraft requires a safe, accurate, and controlled method for simulating jamming failures in lab settings. We adopt a crank-rocker mechanism with a variable degree of freedom (DOF) to construct a novel jamming apparatus that may be dynamically constrained in order to meet this requirement. The apparatus maintains two DOFs when not in use, which permits the latch mechanism to move freely. Both the guiding shafts and the rotation shafts are simultaneously constrained for a jamming test, reducing the mechanism’s DOFs to zero. This operation creates a precise and passive lock that immobilizes the mechanism without the need for an active external load. This approach offers a more realistic simulation of the sudden jamming brought on by wear, foreign object intrusion, or manufacturing tolerances. A theoretical kinematic analysis is then conducted to calculate the mobility of the mechanism and determine the theoretical conditions and transition paths to reach the two functional states. Moreover, the apparatus implements a real-time computational model based on classical planar linkage force analysis and integrates a multi-sensor system. This model converts sensor data into the torques and jamming forces that are actually delivered to the latch. The findings demonstrate that the proposed design accurately simulates latch jamming conditions while allowing for real-time monitoring and quantification of important dynamic characteristics. Thus, by offering a dependable and effective verification solution for cargo door latches, the apparatus greatly improves testing safety and the value of the data gathered.
Ren, Jie, Zeng, Xiaohu, Qiu, Xudong, Xie, Youshui
Analytical Analysis of Wellbore Stresses under Fluid Pressure and In-Situ Stress in Three-Dimensional Wellbores2026-99-08317/30/2026
During fluid injection operations such as fracturing and well killing, the casing, cement sheath, and borehole wall rock are subjected to three-dimensional in-situ stresses and internal pressure. If the equivalent stress exceeds the material’s yield strength, component failure may occur, leading to wellbore failure or even blowout accidents. In order to investigate the stress distribution in wellbores under specific working conditions, a three-dimensional mechanical model of curved wellbores was established. By adopting the superposition principle and stress function method, the influence of horizontal in-situ stress non-uniformity on the fourth equivalent stress of various components was analyzed. The study demonstrates that under three-dimensional in-situ stress, the fourth equivalent stress of each component increases with the rise of horizontal in-situ stress load non-uniformity and azimuth angle. Meanwhile, borehole azimuth angle and in-situ stress load non-uniformity exert a greater influence on the fourth equivalent stress of the casing, while internal pressure has a lesser impact on it. The effects of azimuth angle, horizontal in-situ stress load non-uniformity, and internal pressure on the fourth equivalent stress of the casing are more significant than those on the cement sheath and borehole wall rock. The research results can provide theoretical and technical references for wellbore design and safety improvement, as well as for the structural safety assessment of components such as automotive chassis and body frames under complex dynamic loads.
Zhang, Wenzhe, Jiang, Wu, Guo, Ziwang, Cao, Yinping, Dou, Yihua
Experimental Study on the Temperature Impact of a Typical Cabin Fire on Adjacent Cabins2026-99-08667/30/2026
The cabins of ships are mainly made of steel. When a fire breaks out, the temperature inside the cabin rises rapidly, and an extensive body of heat spreads through the bulkheads to adjacent cabins. Understanding the variation law of the temperature field in adjacent compartments after a fire occurs in the compartments is of great significance for the research on the thermal safety of ship compartments. This paper designs an L-shaped cabin test system. We conduct fire tests of different scales and obtain the temperature distribution of adjacent compartments. The test results show that as the fire area in the pool keeps rising, the temperature in the adjacent compartments keeps rising. Due to the fact that an extensive body of high-temperature smoke produced by combustion is suspended at the ceiling of the compartment of fire, the temperature of the vertically adjacent compartments is higher than that of the horizontally adjacent compartments.
Hu, Wei-guo, Hu, Yang, Wei, Jin, Yuan, Ya-long
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
Systematic Assessment of State-of-the-Art Approaches Available for Variable Camber Morphing01-19-01-00057/29/2026
Aerodynamicists around the globe are developing mechanisms and structures inspired by nature that enable variable camber morphing (VCM) for aerodynamic surfaces. The implementation of the VCM mechanism in an airplane wing enhances the performance and stability during various flight segments. The present review article is focused mainly on the up-to-date VCM methods in a qualitative as well as quantitative approach that are specific to Aircraft/unmanned aerial vehicle (UAV) wing configurations. Initial literature discussions are confined to the conventional mechanisms that enable VCM in different aircraft configurations and the added aerodynamic advantages such as lift enhancement, drag reduction, boundary layer separation, and flow control. However, those designs need either external shape optimization or internal structural refinements to ensure the factor of safety (FoS). The modern aviation industry is also focused on bioinspired technology because of the adaptive flying capabilities and stall-delay characteristics. Therefore, a review of bioinspired VCM methods that are assessed based on the aerodynamic potentials is sequentially organized in the article. Additionally, considerations are motivated by the application of various compliant structural patterns for VCM in the aircraft industry. The discussion indicates the prospective benefits of morphing toward the future of the Green Aviation industry.
Manjunath, S. V., Jini Raj, R.
Landing Gear Structural Health MonitoringAIR6168A (Current)7/27/2026
This SAE Aerospace Information Report (AIR) discusses past and present approaches for monitoring the landing gear structure and shock absorber (servicing), opportunities for corrosion detection, methods for transient overload detection, techniques for measuring the forces seen by the landing gear structure, and methods for determining the fatigue state of the landing gear structure. Landing gear tire condition and tire pressure monitoring are detailed in ARP6225, AIR4830, and ARP6137, respectively. Aircraft Brake Temperature Monitoring Systems (BTMS) are detailed in AS1145.
A-5 Aerospace Landing Gear Systems Committee
Geometric Deep Learning–Based AI Framework for Nonlinear Crash Behavior of Extruded Rails15-19-03-00127/27/2026
Extruded Rails are critical energy-absorbing components in automotive structures designed to mitigate impact loads during the frontal collisions. Traditional crashworthiness design relies heavily on computationally expensive finite element simulations and iterative design exploration. This work proposes a machine learning–driven framework for rapid front extruded rails design using a trained geometric deep surrogate model. A design-of-experiments (DoE) was conducted by varying geometric parameters including width, height, and wall thickness of a thin-walled extruded rail structure. For each design variant, LS-DYNA simulations were performed to obtain performance metrics such as mean crush force and peak crush force. These simulation results were used to train an AI surrogate model capable of predicting crash responses directly from geometric parameters. The proposed approach significantly reduces computational cost by replacing repeated high-fidelity crash simulations with machine learning surrogate predictions. By enabling fast and accurate evaluation of crash response metrics, the workflow shortens design cycles and supports sustainability-driven crashworthiness assessment by reducing simulation resource usage. The framework establishes a scalable, simulation-driven engineering pathway across vehicle platforms and provides a foundation for future closed-loop, AI-assisted crash design workflows.
Kumar, Manik, Srinivasan, Sriram
Research and Application of Flush Adjustment for Multi-Link Retractable Hatch2026-99-16207/24/2026
The adjustment process for multi-link retractable hatches has long relied on personal experience, making it difficult to achieve precise and quantitative length adjustments. This limitation has consistently constrained the efficiency of the adjustment process. This paper aims to analyze the risks and shortcomings in the existing flush adjustment process, simplify the flush adjustment process into a mathematical model, and calculate the required adjustment amount of the actuator length. By simplifying the flush adjustment process and steps, the risk associated with the adjustment process can be reduced, and the efficiency of door step difference adjustment can be improved.
Deng, Qinwen, Shen, Yingdong, Wang, Zhihai, Li, Yixiao, Wei, Xingxu, Gao, Haosen
Numerical Study of Structures for a Next-Generation Supersonic Transport2026-99-16267/24/2026
Because of the increasing requirement for frequent international traveling, developing a new generation of supersonic transport is critical for commercial aviation. The typical features of supersonic transport are a large swept-back wing and thin airfoil, potentially causing excessive tip deflection and triggering aeroelastic divergence. Hence, conducting evaluation, analysis, and optimization of the structures of an SST is essential. This study applied the finite element method to investigate the wing and fuselage structures under aerodynamic loads during cruise for a next-generation supersonic transport aircraft. Deformations and stress contributions were analyzed, showing the feasibility of the structure design and the stress concentration zones requiring reinforcement in the detailed design. Structural optimizations were also conducted, yielding significant weight reduction.
Ding, Menglong, Xu, Zhaoyang, Wang, Yongqiang, Meng, Li, Tan, Jiaxin, Xuan, Jinting, Bie, Dawei, Shao, Lintao
Study on the Aerodynamic Characteristics of Canard Configuration Missile Influenced by Aileron2026-99-16107/24/2026
The canard configuration has been widely adopted in short-range missiles. However, its main drawbacks include difficulties in roll control and a limited angle-of-attack (AoA) range. Compared to conventional canard missiles, the addition of a pair of control surfaces (referred to as “aileron”) behind the canard control surfaces achieves decoupling between the roll channel and pitch-yaw channel. To investigate the influence of ailerons on the aerodynamic characteristics of canard configuration missiles, numerical simulations were conducted for two typical flow conditions: subsonic (Mach 0.5) and supersonic (Mach2.0). The results show that the introduction of ailerons increases the normal force of missiles, causes the center of pressure to shift forward, and reduces the static stability of missiles, thus enhancing their maneuverability. When the ailerons control the roll channel, the effectiveness of the rolling moment remains consistent over the entire AoA range without adverse effects. However, when the canards control the pitch channel, the interference caused by the deflection of the canards on the ailerons leads to increased lift and generates additional nose-up pitching moments, which reduces the pitching moment effectiveness of the missile.
Zhang, Zilun, Xu, Jiasheng, Mei, Zhiwei
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
Research on the Application of Eddy Current Retarders in Aircraft Arresting Systems2026-99-16217/24/2026
At present, the aircraft arresting system in our country is the fixed water turbine type. This kind of equipment cannot achieve the arrestment of multiple aircraft types, and the arresting distance cannot be adjusted. According to these problems of the aircraft arresting system in our country, the eddy current retarding device is added, based on the water turbine braking device of the aircraft arresting system. It derives the differential equation for an aircraft arresting system with a water turbine brake and eddy current retarder using mathematical modeling. Four types of aircraft parameters are selected, and MATLAB is used as a simulation tool to verify the reliability of the arresting system after installing the eddy current retarder. This research can improve the arresting support ability and make the arresting device meet the arresting requirements of different types of aircraft.
Wei, Yan, Feng, Chunchun, Wang, Jianwu, Li, Binghong, Yang, Yang
Lightweight Optimization Design of Subframe Structure Based on Sensitivity Analysis2026-99-16397/24/2026
In order to meet the needs of national energy conservation and environmental protection policies, a typical chassis structure lightweight method based on sensitivity analysis of 13 strength conditions was proposed. Firstly, the finite element model of the subframe of a certain model is established, and the impact strength and static strength of the subframe structure are analyzed by the finite element method. Secondly, the sensitivity analysis of 13 strength conditions was carried out for the 12 main sheet thicknesses in the finite element model. Based on the results of the sensitivity analysis, the plate thickness of the components that is conducive to lightweight and has little impact on the 13 strength conditions of the subframe was selected as the design variable. The size optimization was carried out with the goal of minimizing the mass of the subframe and the constraint that the maximum Von Mises stress of the unit, where each material is located, did not exceed the yield strength of the material. The optimization results show that the performance of the subframe under 13 strength conditions meets the requirements of the index, and the weight of the subframe is reduced by 1.37 kg / 9.6%.
Jing, Min, Jia, Zhilong, Zhang, Hualei, Liu, Minjie, Gan, Xinhua, Gao, Jinyu
Integrated Guidance and Control Design Based on Sliding Mode Control Theory2026-99-16337/24/2026
In order to meet the demand for missile miniaturization and simplify the system complexity, this paper designs a guidance control integration method according to sliding mode control based on the longitudinal plane motion model, which is combined with the theory of sliding mode control. The design realizes tracing of attack angle to line-of-sight angle through sliding mode control of the outer loop, and the tracking of the control volume rudder deflection angle to the virtual control volume angle of attack through the sliding mode control of the inner loop. The stability of the guidance law is also verified by the Lyapunov function. The simulation results show that the guidance law can hit the target successfully, which verifies the feasibility and effectiveness of the design method.
Bai, Jiajun, Ming, Chao, An, Zhichao, Niu, Zhaoqi, Wen, Guangbao
Biomimetic Design and Numerical Analysis of a VIV Suppression Fairing for Offshore Risers2026-99-16407/24/2026
As oil and gas exploitation advances into deep seas, risers linking offshore platforms and subsea extraction systems endure long-term complex marine loads. Fatigue damage from Vortex-Induced Vibration (VIV) has become a key factor limiting the safe operation of deep-sea engineering structures. To address this issue, a bionic adaptive rotating fairing, which is adjustable to ocean current directions, was designed. Its main components include buoyancy blocks, a fairing with spiral guide rails on the inner wall, and clamps, which work together to reduce VIV by regulating flow patterns. Numerical simulations of concave and convex fairings showed that under subcritical flow, shifting from a concave to convex cross-section gradually enhances the fairing’s drag and lift reduction effects on risers, with a steady improvement trend. Further comparisons were made between 0.25D convex fairings, 0.35D convex fairings, and bare risers, focusing on drag/lift reduction, vortex shedding frequency, and Strouhal number. Both convex fairings exhibited similar VIV suppression performance to the bare riser, but differed significantly in the percentage reduction of vortex shedding frequency and Strouhal number. Thus, the 0.25D convex fairing was identified as the optimal configuration for VIV suppression among the concave-convex fairings studied.
Zhang, Xu, Song, Guangming, Wang, Baozhong, Zhao, Jinpeng, Chen, Qianshuo
Load Analysis of Flap and Slat Actuators in Aircraft High-Lift Systems2026-99-18027/17/2026
This study develops an end-to-end load analysis scheme for flap and slat actuators, which comprise the aircraft’s high-lift system, and the analysis results are directly integrated into hardware optimization. Because they shoulder heavy responsibilities during the takeoff and landing phases, whether they can remain rock-solid under complex aerodynamic conditions or even remain unmoved in emergencies is directly related to their overall safety performance. This work process is closely linked and includes three major links. First of all, according to the CCAR-25.301 standard, the load envelope under normal working conditions is sorted out, and the limit cases of abnormal faults are exhausted. Subsequently, ANSYS Workbench pulled silk and peeled off the cocoons to capture the peak stress at the engagement between the output shaft and the gear. In the end, the closed-loop verification of the customized test bench made the theoretical calculations and the hardware-measured data exactly the same. The entire package provides designers with hardcore data support, and always uses airworthiness, not convenience, as the criterion when improving actuator performance.
Xu, Yuanze
Flight Test Analysis Method for Aerodynamic Characteristics of Helicopter Rotor in Level Flight2026-99-18217/17/2026
To analyze flight test failures, ensure flight safety, and provide data support for the aerodynamic design of helicopters, it is necessary to conduct aerodynamic characteristic analysis of helicopter rotors based on flight test data. This article establishes a helicopter rotor aerodynamic model and an aerodynamic parameter identification method in level flight. In this article, we take the flight test data of a helicopter’s level flight performance as an example, and use the genetic algorithm and Particle Swarm Optimization for parameter identification calculation. We obtain aerodynamic parameters such as rotor angle of attack and rotor lift-to-drag ratio in the helicopter’s level flight state, and so on, and analyze the aerodynamic characteristics of the helicopter’s rotor. The results show that the method established in this paper can accurately and effectively obtain the aerodynamic parameters of the helicopter rotor through flight tests. It can also evaluate the aerodynamic characteristics of the helicopter rotor and meet the requirements of the American standard ADS40 for obtaining the aerodynamic characteristics of the helicopter through flight tests. Thus, it has great engineering application value.
Zhao, Jingchao
Dynamic Characteristics Study of the Deployment Process of Aircraft Folding Wing2026-99-18607/17/2026
Folding wing mechanisms are widely applied in aircraft structural design. This design reduces the size of the aircraft, making it easier to store and transport. Whether the foldable wing can successfully deploy determines the completion of the flight mission. Therefore, it is crucial to study the kinematic and dynamic parameters of the mechanism during the deployment process. The deployment of the folding wing typically occurs within milliseconds. The flow field imposes aerodynamic loads on the mechanism, causing it to move, while the large deformation motion of the mechanism, in turn, affects the aerodynamic loads from the flow field. This is a typical fluid-structure interaction (FSI) process. Traditional CFD methods for solving the deployment process in a decoupled manner often result in large errors and cumbersome procedures. To investigate the aerodynamic loads and deformation of the folding wing mechanism during deployment, the ALE algorithm in LS-DYNA was selected to directly solve the kinematic and dynamic parameters of the mechanism in unsteady flow fields, guiding the design of foldable wing mechanisms.
Wei, Ting, Tong, Zongkai, Li, Naitian
Aircraft Evacuation Simulation Study2026-99-18457/17/2026
This study analyzed the evacuation process of aircraft cabin personnel, with a focus on the impact of emergency exit configuration on evacuation efficiency. The research results indicated that the number and location of emergency exits are key factors determining evacuation time. In the case of only one exit, the evacuation time was significantly longer than that of multiple exit configurations. Utilizing three exits could reduce the evacuation time to 76 seconds. Additionally, the age and gender distribution of passengers, as well as priority rules, also had a significant impact on the evacuation process. The study further demonstrated that the activation of emergency exits and rear cabin doors could significantly enhance evacuation efficiency, while the opening of the front cabin door had a relatively smaller effect.
Wang, Kai, Wu, Bin, Li, Guolin, Yue, Chaoyu, Zeng, Tai, Su, Zhengliang
Multi-Frame Centroid Extraction Method for Optical Navigation During the Approach Phase of Small Body2026-99-18517/17/2026
Autonomous optical navigation is one of the important navigation methods for the small bodies approach phase. To improve optical navigation performance during the approach phase to a small body, this paper presents a method for extracting the target centroid from sequential optical images. The process begins with fitting a minimum enclosing ellipse to the detected contours in each frame to obtain an initial estimate of the centroid. Building upon this, edge corner points across adjacent images are matched using normalized cross-correlation, and their displacement is tracked using optical flow techniques. The observed pixel trajectories are analyzed, and a predictive model of pixel motion is formulated based on the geometric relationship between the detector and the small body. By combining the directly extracted centroids with the predicted motion of key pixels, a fusion strategy is developed to improve the reliability of the centroid estimation. Finally, numerical simulation results demonstrate that the method significantly improves the accuracy of centroid extraction, thereby enhancing the overall performance of optical navigation during approach operations.
Liu, Jing, Zhu, Shengying
Key Technologies of Aircraft Flight Test Based on Structural Control2026-99-18257/17/2026
A comprehensive solution integrating advanced sensor technology, structural dynamics models, and intelligent control algorithms is proposed to address the shortcomings of traditional flight testing techniques in monitoring and controlling aircraft structures under complex flight conditions. By establishing precise aircraft structural dynamic equations through fiber optic sensors, an accurate description of the dynamic characteristics of the aircraft structure can be achieved. A distributed structural monitoring system is constructed through FBG to monitor the physical quantities, such as strain and temperature, of key parts of the aircraft in real time during flight testing. Based on the real-time monitoring data, the structural state of the aircraft can be predicted, and the structural response can be actively adjusted by controlling the actuator. The experimental results show that this technology system effectively improves the accuracy of structural monitoring and the effectiveness of control during aircraft flight testing, providing strong guarantees for the safety and reliability of aircraft flight testing, and laying a solid foundation for aircraft structural design optimization and flight performance improvement.
Gao, Sheng
The Impact of Powerplant on Stall Characteristics of Propeller Aircraft2026-99-18377/17/2026
This study focuses on a compact-layout propeller aircraft, investigating how its powerplant influences stall characteristics via combined theoretical analysis of aerodynamic principles and validation with flight test data. Special attention is paid to the effects of propeller slipstream, appropriate evaluation criteria are selected to assess the aircraft’s high-angle-of-attack performance and stall behavior, and the Weissman chart criteria are further adopted to analyze its lateral-directional departure tendencies. A theoretical analysis of the stall characteristics of compact-layout propeller aircraft is conducted. Through flight test data analysis, the stall characteristics of compact-layout propeller aircraft are studied, with an emphasis on understanding how slipstream effects influence their longitudinal and lateral-directional stall characteristics.
Fang, Shengyou, Yang, Xiaoli, Jiang, Tianjun, Fu, Yi
Research on Explicit Topology Construction and Shape Optimization via Hole Deformation2026-99-18367/17/2026
Topology optimization provides innovative solutions for lightweight structural design by rationally arranging material distribution. It enhances structural performance while reducing material consumption and structural weight, thereby significantly lowering production and operational costs and generating enormous economic benefits. In the development of topology optimization, the density-based method has gained widespread adoption due to its easy-to-understand principles. However, this method still faces the following challenges when applied to engineering applications. First, the geometric models generated by topology optimization lack explicit parameter descriptions, leading to data interaction barriers with Computer Aided Design (CAD) systems. Second, due to element discretization and density penalty mechanisms, structural boundaries exhibit rough and blurred characteristics. These problems severely constrain the iterative efficiency of structural design and manufacturing feasibility. To address these issues, this paper proposes a strategy for geometric reconstruction and shape optimization of topology optimization results. The reconstruction process begins with extracting isolines from the density field as a set of contour points. These points are subsequently interpolated with B-spline curves to explicitly represent the geometric boundaries. Shape optimization is then carried out by adjusting the positions of the B-spline control points. Compared to post-processing methods based on graphics techniques for topology optimization, which ignore the volume constraint and performance loss, the structures reconstructed in this paper exhibits the following advantages: structural boundaries are smoothed and characterized with explicit parameters, reducing performance loss caused by geometric reconstruction while satisfying volume constraints. This paper successfully establishes compatibility between topology optimization and CAD systems, facilitating the transition from conceptual design to manufacturing.
Tang, Yuting, Li, Yu, Luo, Jiaxiang, Chen, Junwei, Zhou, Weien, Yao, Wen
Machine Learning-Based Prediction of Landing Dynamic Response for Bogie Landing Gear2026-99-18297/17/2026
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Zhang, Hong, Fang, Wei, Zhao, Junfeng
Analysis of Structural Stiffness Indicators of Manned Lunar Vehicles2026-99-18277/17/2026
The structural stiffness of a manned lunar vehicle is a core indicator ensuring its stable operation in the complex lunar environment. The vehicle’s body structure must meet multiple requirements, including high stiffness, lightweight design, and adaptability to lunar surface conditions. Since lunar gravity is only 1/6 of Earth’s and the terrain is rugged and dusty, the body structure must employ a high-stiffness design to withstand driving impacts and resist deformation, thereby preventing mechanical failures or safety hazards for crew members caused by excessive structural distortion. However, excessive structural stiffness would result in an overweight vehicle body, conflicting with the spacecraft’s lightweight requirements. Thus, the structural stiffness index should be optimized to a lower value while ensuring safe operation during lunar surface driving without compromising performance. This paper calculates and determines the structural bending and torsional stiffness indicators for the manned lunar vehicle’s body through simplified model calculation and the FEA method.
Shen, Zhenghui, Wu, Yingjia, Yang, Jianfeng, Wang, Weijun, Zhang, Chongfeng, Han, Liangliang
Analysis of the Nonlinear Behavior of the Composite Helicopter Horizontal Centralwing Skin2026-99-18327/17/2026
Test results of the composite helicopter horizontal central-wing under symmetric and unsymmetric loads showed that the strain value of the lower skin would turn from negative to positive, showing a nonlinear behavior. FEM results of the linear and nonlinear analytical approach showed a great difference. The strain value of the lower skin remains negative and decreases linearly when using a linear FEM analysis. The strain value of the lower skin would turn from negative to positive when a nonlinear FEM analysis is applied, and this result agrees well with the test results. Besides, the results of the FEM buckling analysis showed that the buckling load of the lower skin is considerably higher than the value at which the skin would show a nonlinear behavior. Therefore, the specific behavior is a result of the nonlinear property of the structure, not buckling.
Wang, Zhe, Zhang, Tiesong, Li, Mengjia, Chen, Puhui, Huang, Zhiwen, Wang, Binwen
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