Browse Topic: Hazards and emergency operations

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Multi-Dimensional Suitability Analysis-Based UAV Platform Selection for Chemical Contaminant Detection Sensors2026-99-220311/6/2026
Unmanned aerial vehicles (UAVs) equipped with chemical contaminant sensors offer an innovative approach for rapid and safe remote chemical reconnaissance. However, the proliferation of diverse UAV platforms presents a critical challenge: how to select the optimal platform for a given mission scenario. This paper establishes a systematic suitability analysis framework for deploying chemical contaminant sensors on three mainstream UAV platforms-multirotor, fixed-wing, and vertical take-off and landing (VTOL) types. We analyze payload capacity, endurance, flight stability, environmental adaptability, and mission system integration. To reduce decision subjectivity, we develop an Analytic Hierarchy Process (AHP)-based quantitative evaluation model incorporating expert surveys and consistency tests to validate the weighting process. Beyond the evaluation framework, we explore key engineering challenges in platform-sensor integration, including aerodynamic interference, vibration and electromagnetic compatibility, and power management. We compare quantitative measurements and qualitative features across platforms in simulated mission scenarios. The resulting selection criteria provide a theoretical basis and a reproducible decision-support framework for developing chemical detection systems applicable to emergency response, environmental monitoring, and public safety.
Liang, Ting, Wen, Hao, Qi, Yelin, Yang, Wen
Commercial Vehicle HVAC Digital Twin: From Component Validation to R134a Closed Cycle Accuracy2026-28-017811/5/2026
This paper presents a one-dimensional digital twin of a commercial vehicle heating, ventilation, and air-conditioning (HVAC) system, developed in MATLAB and Simulink with Simscape. The model integrates a belt-driven, engine-speed-dependent R134a vapor-compression cycle with a reduced-order cabin thermal network. The refrigeration loop incorporates a positive-displacement compressor, condenser, thermostatic expansion valve, evaporator, and receiver, with the heat exchangers represented using two-phase and moist-air formulations. The cabin model accounts for six surfaces with parallel glazing and opaque thermal paths, solar and long-wave radiation on exterior panels, occupant heat and moisture loads, and speed-dependent external convection, parameterized for validation drive segments. The framework is designed for traceability from component-level state variables to system-level outcomes, enabling staged validation using pressure and temperature signals across the refrigerant loop and cabin temperature response. Validation was performed against controlled climatic chamber data, including a hot-soak period with the air-conditioning off followed by cool-down tests at two steady vehicle speeds. Simulation results were resampled to match measurement timestamps, showing strong agreement with cabin temperature dynamics, with a root mean square error of ~2 °C and correlation of 0.99 in the transient-excluded window. Refrigerant-side pressures and temperatures exhibited segment-dependent accuracy, sufficient for calibration and strategy assessment. Simulation-based screening of cool-down behaviour and refrigerant-loop states provides a reusable framework before repeated vehicle testing, reducing the calibration effort for faster HVAC system evaluation. Overall, the model supports rapid iteration, ensures thermodynamic consistency through enthalpy-based checks, and provides a practical foundation for controller development and future in-the-loop applications.
Kumar, Nitesh, Duraiswamy, Vijayaraj, M. L., Sankar, Kumar, Vijay Bhooshan
Experimental Investigation on Flame Characteristic for Civil Aircraft Propulsion System Fireproof Test2026-99-231710/30/2026
In order to meet the airworthiness regulations, the civil aircraft propulsion system needs to carry out the necessary fireproof test. The measurement of the flame temperature is very essential for the certification and validation of fire protection thermal simulation models, and also helps to establish the empirical understanding of complex flame behaviors. In order to investigate the influence of the specimen on the flame temperature distribution, the two dimensional flame temperature distribution of the free burning test and several fireproof tests, including titanium panel fireproof tests, stainless steel panel fireproof tests, composite laminated panel fireproof tests, honeycomb sandwich panel fireproof tests, were experimental investigated in this paper. The test results shows that panel specimens significantly alter the temperature distribution of the standard flame and interfere with radiation heat transfer measured by thermocouple, resulting in a significant reduction in the temperature gradient of the flame and a obvious increment in the temperature of the surrounding non-flame-impinging zone. The central flame-impinging zone exhibits minimal temperature variation compared to the baseline flame at 1093 °C, with temperature elevation restricted to approximately 40 °C (within 4% deviation). Both metal panels and composite panels demonstrate consistent trends in affecting flame temperature distribution. However, compared to metal panels, composite materials induce smaller temperature gradients and more uniform temperature fields. Multiple burning tests on same panel progressively intensify the oxidation on the specimen surface, leading to a gradual decrement in flame temperature. Especially, this temperature reduction becomes statistically significant as early as the second time burning test.
Chen, Fang, Guo, Junxian, Peng, Sen
Research on Dynamic Force Formation in Aerospace Search and Rescue Missions Based on an Improved Contract Net Algorithm2026-99-231010/30/2026
Aerospace search and rescue plays a crucial role in ensuring the safety of manned space missions. As China’s manned space program progresses toward normalization and higher-frequency, flight-like missions, the conventional static formation mode of search and rescue forces may no longer be adequate. To achieve the “high frequency, high parallelism, and multi-type” goals in future missions, we propose a more efficient contract net algorithm that incorporates hierarchical bidding and joint evaluation to dynamically organize and optimize distributed tasks. The force formation challenge is modeled as a distributed dynamic programming problem with strong spatiotemporal constraints, and a task-capability-context matching is developed to overcome the adaptability limitations of static formation modes in flight-type missions. To enhance the contract net, we introduce a Level 1 bidding algorithm based on efficacy objectives, which builds a “timeliness-loss-reliability” objective function using these three indicators. Then, we introduce a Level 2 bidding algorithm focused on equilibrium objectives by employing “rigid locking for high-priority tasks and dynamic optimization for secondary tasks” to alleviate resource load imbalance. Next, we implement a ”joint bidding” mechanism, which allows resources to form alliances and bid collaboratively. Simulation results demonstrate that the improved algorithm accelerates task formation and provides a systematic, scientific solution for aerospace search and recovery force formation.
Lv, Nan, Liu, Ruirui, Li, Donghao, Liu, Xin
Design and Performance Analysis of a Hilbert Fractal Antenna for Corona Discharge Detection2026-99-290310/19/2026
Fractal antennas have attracted considerable attention due to their compact geometry and favorable electromagnetic characteristics, particularly in broadband and multiband applications. In this paper, a fourth-order Hilbert fractal antenna is designed and analyzed for radio frequency signal reception in the 200-300 MHz band. The design is motivated by the spectral characteristics of electromagnetic radiation generated during corona discharge, whose primary energy is concentrated within this frequency range. The proposed antenna is optimized in terms of return loss and bandwidth to ensure effective signal reception. Simulation results demonstrate that the antenna exhibits satisfactory impedance matching and achieves stable performance within the target frequency band. Based on the optimized design, a prototype is implemented and evaluated through laboratory experiments. Experimental results indicate that the proposed antenna can effectively capture radio frequency signals associated with corona discharge, demonstrating reliable non-contact detection capability. The study provides a feasible antenna design approach for corona discharge monitoring and offers potential applications in avionics system health management and electromagnetic sensing.
Hei, Guoyu, Li, Shidong, Wu, Yang, Su, Zhenxia, Ye, Hongyan
Analysis of Structural Stress Distribution and High-Temperature Performance of Load-Bearing Components in External Fire Scenarios of Steel-Structured Aircraft Models2026-99-297510/19/2026
This paper focuses on three typical external fire scenarios in aircraft firefighting and rescue training systems: engine fires, external fuselage skin fires, and nose landing gear fires. Unlike internal fires, these external fires expose the load-bearing steel structure directly to flame radiation and high-temperature environments, and the cooling methods and stress conditions associated with each fire scenario differ significantly. Based on the ABAQUS finite element platform, this study established a three-dimensional finite element model comprising an engine model, a water-cooled thermal insulation structure, and a fuselage support system, fully accounting for the actual structural layout and cooling protection measures of the training system. Material parameters were derived from measured performance data for Q355NH steel. The calculation results indicate that under the three types of external fire scenarios, the steel structure model maintained sufficient structural safety margins, with a minimum safety factor of 4.49 and a maximum of 9.43. This demonstrates that the current design meets the safety requirements for prolonged external fire training, providing a reliable mechanical basis for the safe operation of the ARFF training system.
Gao, Jianwei, Xu, Xiaodong, Huang, Min, Wang, Shumin, Shi, Yajie, Zhang, Yun
A CTCM-ALA Adaptive Embedded Fusion Optimization Method for UAV Path Planning in Complex Medical Rescue Environments2026-99-290510/19/2026
To improve the accuracy and safety margin deficiencies of unmanned aerial vehicles in autonomous medical emergency search-and-rescue missions, this paper develops an adaptive embedded fusion optimizer named CTCM-ALA for rescue UAV path planning. The proposed algorithm hybridizes the tribe-competition member-cooperation strategy and artificial lemming algorithm to construct hierarchically adaptive initial populations, speed up convergence and prevent local convergence traps. Tests on 12 CEC2017 functions prove its better optimization performance. Real-world applications in dense urban and complicated topographic medical rescue cases verify its reliability and precision.
Chen, Yuhan, Xiong, Junhui, Li, Yuesheng, Zhou, Yifan, Yao, Junjie, Li, Rujun
Research on Network Attack and Defense Technology in LEO Large-Scale Constellation Networking2026-99-298710/19/2026
With the rapid development of LEO large-scale constellations, space networks evolved into a critical domain of cyber confrontation. The heterogeneous architecture, open inter- satellite links and limited on-board processing capability introduce serious security risks. Aiming at advanced persistent threat (APT), data poisoning and spear phishing, this paper analyzes new attack mechanisms in LEO constellation networking, satellite-ground collaboration and communication - computation convergence scenarios. A satellite-ground-link collaborative active defense model is proposed to improve the security and stability of LEO constellation systems.
Guan, Mengmeng, Xia, Ming, Fang, Liang, Li, Ruxue, Lv, Xing
Aerospace & Defense Technology: Oct 202626AERP1010/8/2026
Terabit Optical Communications in Space: Engineering High-Speed Networks for Data Centers in Orbit Mild Hybrids: A Current-Gen Bridge to Electrifying Military Ground Vehicles The Integrated and Flexible Approach to Large-Scale Metrology: How Integrating Laser Trackers and Modular Arms Creates a 'Unified Nervous System' The Defense Industry Continues to Meet CMMC Phase II Requirements Despite 60-Day Pause In Space, No One Can Hear You Stream AMD to Bring UCIe Connectivity to Select Versal Adaptive SoCs How Special Interface Gages Provide Microscopic Precision for Designing Ballistic Missiles The pristine precision needed to certify the nation's underwater nuclear deterrent is anchored on the talents of civilian scientists at a Navy laboratory in Southern California. Rapidly Testing Deployable Systems Sandia National Laboratories is evaluating portable security architectures that combine radar, drones, ground sensors, cameras and wireless communications networks into a single rapidly deployable system for remote and austere environments. Testing focuses on sensor integration, resilient communications and edge-based data processing to improve situational awareness while operating within real-world bandwidth constraints. Tailored Surface Vibrations to Improve Aerodynamic Performance in Passenger Jets University of Colorado Boulder researchers have demonstrated two new phononic flow-control concepts, super-resonance and scatterless interference, that use engineered subsurface vibrations to interact with boundary-layer airflow across a broader range of turbulence frequencies than previously possible. By delaying flow instabilities without altering a wing's external shape, the technology could reduce aerodynamic drag and improve fuel efficiency in passenger aircraft. New Type of Attack Can Slip Past the Defenses in Your Computer's Processor MIT researchers found a way to exploit a split-second gap in chip security - and used it to acquire a Linux system's password file. Army Tests Safer Electrical Connectors for Ground Vehicle Readiness U.S. Army DEVCOM Ground Vehicle Systems Center engineers are evaluating cadmium- and hexavalent chromium-free electrical connectors designed to reduce hazardous material exposure while maintaining corrosion protection, electrical performance, and long-term vehicle sustainment.
Simulation of Liquefied Petroleum Gas Truck Accidents during Heatwave Periods Using the Areal Locations of Hazardous Atmospheres Program2026-01-507910/1/2026
In this study, the effects of heatwaves (HWs) on liquefied petroleum gas (LPG) leaks were analyzed using the Areal Locations of Hazardous Atmospheres (ALOHA) program. For this purpose, data from an accident at a gas station in the Eryaman District of Ankara in January 2024 were utilized. Approximately 40 m3 of LPG was released during the incident, but no explosion occurred. The accident was simulated using atmospheric data from the accident date in the ALOHA program. In the simulations, emissions of propane and butane—the primary components of LPG—were modeled separately. To simulate the LPG leak during a HW, a HW was first defined based on daily maximum temperature data. The threshold was set at the 90th percentile, and temperatures persisting for three or more consecutive days were classified as a HW. Using this definition, a four-day HW in Ankara in July 2024 was identified. The atmospheric conditions during this HW were input into the ALOHA program for simulation. The study compared the simulation results of the LPG leak in January with those during the HW period. The findings showed that the sub-explosion areas for propane and butane during the HW were 2% (95% CI: 0.91–1.15, p > 0.05) and 9% (95% CI: 0.84–1.42, p < 0.05) larger, respectively, than those during the accident in January. As a result, the study highlights the need for stricter safety measures during summer months when transporting explosive materials.
Öztürk, Yunus
Effect of Space Radiation on the Properties of Methyl Phenyl Vinyl Silicone Rubber (MPVQ) Compound2026-99-14249/11/2026
In this study, the influence of space radiation on the properties of methyl phenyl vinyl silicone rubber (MPVQ) compounds is systematically investigated. The results reveal that with increasing radiation dose, the appearance of MPVQ compounds changes from white to pale yellow and then to grayish-yellow, while their hardness continuously increases. Both the tensile strength and tear strength of the samples exhibit the S-shaped variation curves with radiation dose. At a radiation dose of 1 × 10^6 Gy (Si), the tensile strength, elongation at break, and tear strength decrease by 20%, 89%, and 69%, respectively. When the radiation dose exceeds 1 × 10^6 Gy (Si), both the tensile strength and tear strength rebound moderately. However, further increases in the dose cause both properties to decline again. By contrast, the elongation at break decreases consistently throughout the dose range. Besides, the samples are non-flammable in the presence of open flames. According to these experimental results, the MPVQ products can meet the 15-year service lifetime requirement for the static spacecraft, although their elasticity and load-bearing capacity could be substantially diminished, leading to increased brittleness and susceptibility to fracture under stress. However, some physical or chemical modification of the MPVQ materials is definitely needed for their further application in the dynamic mechanism for the long-life spacecraft that are directly exposed to the space environment. In our opinion, the results shown in this work could provide some necessary guidance for the further development of the related materials in the related field.
Wang, Peng, Chen, Yacan, Li, Jiaxin, Wang, Nan, Zhao, Tianqi, Liu, Hanliang, Huang, Zhipeng, Huo, Xiubing, Sun, Wei
Ultrasonic Frequency-Domain Reverse-Time Migration Imaging Incorporating Element Directivity Correction2026-99-14199/11/2026
The finite width of ultrasonic array elements results in a non-uniform angular radiation pattern of elastic waves in solids, deviating from the ideal point-source assumption commonly adopted in reverse-time migration (RTM). This angular radiation non-uniformity produces a crack tip-dominated imaging amplitude with weak crack flank representation, manifesting as a pronounced depth-dependent amplitude imbalance along vertically oriented defects. As a result, cracks may be misinterpreted as point reflectors, which compromises the reliability of characterization in ultrasonic nondestructive testing (NDT). This study proposes an ultrasonic frequency-domain reverse-time migration (FDRTM) imaging method incorporating element directivity correction. A longitudinal-wave directivity model in solids is formulated in the frequency domain and normalized at each frequency to ensure consistent scaling during multi-frequency stacking. During backward wavefield reconstruction using full matrix capture (FMC) data, the angular-dependent energy distribution associated with the receiving direction is explicitly corrected, rebalancing the angular energy distribution in the reconstructed wavefield. Defect imaging is then performed using a frequency-domain cross-correlation imaging condition, followed by stacking over frequency and normalization. Validation experiments were conducted on an artificially manufactured vertical crack in a 7075 aluminum alloy specimen. The results indicate that, relative to conventional RTM, the proposed method reduces crack tip dominance and enhances the relative visibility and continuity of crack flanks. Compared with conventional RTM, the peak imaging amplitude increases by 22.44%, and the amplitude at a depth of 6.8 mm is enhanced by 24.39%. In addition, the proposed method outperforms the total focusing method (TFM) in crack profile continuity and the relative visibility of crack flanks. The results confirm that incorporating element directivity correction into frequency-domain RTM mitigates depth-dependent amplitude imbalance and restores crack flank visibility, thereby improving the reliability of crack defect characterization in ultrasonic NDT.
Chen, Si, Zhang, Yifeng, Ma, Tengfei, Xu, Zheng, Jiang, Jiansheng, Gao, Jiaqi
Emergency Rescue Resource Allocation Model and Reasoning Prediction Method for Expressway Reconstruction and Extension2026-99-15489/11/2026
During expressway reconstruction and extension, when a traffic accident occurs, how to make a scientific and reasonable allocation of emergency resources is the premise and basis for efficient rescue. In view of the reconstruction characteristics and the complexity of emergency rescue, the number of casualties, the damage degree of road facilities, the number of damaged vehicles, the range of hazardous chemicals, the size of the fire, and the traffic order were used as the accident attribute indexes to build a historical accident set (case database). The allocation of emergency rescue resources was predicted using case-based reasoning techniques. Also, the corresponding reasoning prediction method was proposed. The research shows that this model can accurately predict the demand for emergency rescue resources during the period of expressway reconstruction and extension, which has good availability and operability, and provides methodological and modeling support for the emergency rescue resource decision system.
Ran, Jin, Zhan, Shiyang, Kadir, Ahmetjan, Ma, Jiarui, Dai, Xiaomin
Large-Scale Helicopter Medical Rescue Task Allocation Method Based on Improved NSGA-II Algorithm2026-99-15769/11/2026
Helicopter-based medical rescue can provide quick response and a wide coverage area; these two points are important in large-scale disaster rescue operations. Scientific helicopter scheduling affects both rescue efficiency and operating cost. To address the helicopter scheduling problems under large-scale disaster scenarios for aerial medical rescue, this paper studies the process and features of aerial medical rescue and establishes a helicopter scheduling model. The goal is to minimize both the time taken for the mission and the amount of money spent on it, and at the same time, make sure that everyone who needs help gets rescued. To solve the shortcomings of the traditional NSGA-II algorithm, such as being prone to falling into local optimum and low efficiency, a feasibility-first NSGA-II algorithm is proposed to assist with helicopter scheduling. This approach uses Latin Hypercube Sampling (LHS) for initialization to improve its global search capability and performs a feasibility check before sorting to reduce redundancy in the solution space and improve the optimality of the outcomes and the speed of computation. The simulated experiment shows that the proposed algorithm has higher efficiency, stability, and better performance than the traditional heuristic algorithm.
Lu, Xun, Liu, Hu, Tian, Yongliang, Zhang, Nan
Numerical simulation of downwash airflow of rescue helicopter rotor2026-99-12949/4/2026
The helicopters conducting carrier deck operations and performing maritime rescue missions experience significant impacts from the downwash generated by their rotors, affecting both landing performance and the surrounding environment. Addressing the unclear mechanisms of downwash effects during water rescue operations, this study employed Computational Fluid Dynamics (CFD) methods, including overlapping grids, to investigate the operational characteristics of helicopter rotor airflow. Numerical simulations were conducted under various operating conditions, including different inflow velocities and rotor speeds. Based on the calculation results, the implementation process of helicopter rescue operations is proposed. These findings provided valuable guidance for helicopter water rescue operations. The results showed that as the rotor speed of the rescue helicopter gradually increased, the force of the rotor downwash flow on the water surface was greater. Moreover, when the rescue helicopter had an incoming flow velocity, the interference of the rotor downwash flow on the water force could be reduced accordingly.
Feng, Xu, Cui, Jia, Zhang, Yi, Han, Qingtian, Liu, Wei, Xing, Li, Wang, Jingyu
Design and Performance Verification of a Wheel-Track Transformable Mobile Platform Based on a Four-Bar Mechanism for Rescue Scenarios2026-99-12469/4/2026
Contemporary disaster rescue operations face challenges due to complex and hazardous terrains. Existing rescue robots with single locomotion mechanisms (wheeled, legged, tracked) and some hybrid ones have limitations in adaptability, efficiency, or structure. To meet the dual demands of complex terrains and limited space, this paper proposes a wheel-track transformable mobile platform based on a four- bar mechanism, which adopts a modular structure. A servo motor drives the active link to adjust the spatial position of the movable link (equipped with movable wheels), enabling smooth switching between wheeled and tracked modes. Key link lengths are determined via kinematic analysis, and a two-stage gear transmission system is designed. Adams simulation verification shows the platform completes wheel-track mode conversion on flat ground without component interference and can lift the center of gravity (CG) to surmount obstacles during slope climbing. The platform's feasibility is verified, providing a technical reference for designing highly adaptable rescue robots suitable for small spaces and complex terrains in post-earthquake or post-disaster scenarios.
Ma, Shangyuan
Ultrasonic Guided Wave Thickness Measurement of Cortical Bone with Soft Tissue2026-99-12209/4/2026
Early diagnosis of osteoporosis is crucial for preventing fractures and improving the quality of life of patients. In clinical practice, the mainstream diagnostic methods, such as dual-energy X-ray absorptiometry (DXA), are limited by high equipment costs and ionizing radiation, resulting in a low coverage rate of large-scale early screening. Only less than one-third of brittle fracture patients have received a DXA assessment. To address this issue, this study proposes an innovative diagnostic method based on ultrasonic guided wave technology. This technology is cost-effective and portable, and it overcomes the limitations of X-ray detection in terms of its unsuitability for large-scale early diagnosis. The Young’s modulus and Poisson’s ratio of water are similar to those of soft tissue, so this method utilizes water coupling to simulate the environment of soft tissue around the bone and combines the transverse isotropy of cortical bone, which is an important characteristic that most existing models ignore, to analyze the propagation of guided waves in anisotropic cortical bone. Through the processing of ultrasonic signals using two-dimensional short-time Fourier transform (2D-STFT), the local thickness of cortical bone can be inverted. By establishing a fluid-coupled orthotropic anisotropic plate model, deriving the dispersion equation, solving the theoretical method for the dispersion curve, using the bovine long plate to construct a water-coupled detection platform, and obtaining experimental data to invert the thickness of the bone plate, the local thickness of the bone plate was obtained, proving that this method can effectively reconstruct the thickness changes of anisotropic and variable cross-section cortical bone under simulated soft tissue conditions, with an average relative error of 13%. This lays the foundation for subsequent in vivo experiments and provides a reliable solution for large-scale early osteoporosis screening.
Nong, Kexin, Li, Bing
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
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 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
Micro-Groove Fabrication and Simulation Analysis on PEEK Surface under UV Nanosecond Laser Irradiation2026-99-02257/31/2026
This study investigates the interaction mechanism between ultraviolet nanosecond pulsed lasers and polyetheretherketone (PEEK). By integrating finite element simulations with experimental validation, the work explores the laser microtexturing characteristics of PEEK surfaces and evaluates the influence of microtextures on the material’s surface biocompatibility. First, the interaction between the laser and the PEEK polymer was analyzed, and a laser ablation model was established using the COMSOL Multiphysics simulation platform. Using finite element simulation, the effects of spot overlap ratio were investigated by adjusting the average laser power, while the influence of single-pulse energy on the ablation characteristics of the PEEK surface was examined by varying the scanning speed. Subsequently, ultraviolet nanosecond laser processing experiments were conducted on planar PEEK microtextures based on the simulation results. Taking surface microgrooves on PEEK as representative structures, the variations in groove depth and width under different combinations of laser parameters were analyzed. The parameters, including average laser power, scanning speed, and repetition frequency, were optimized to identify processing conditions that yield stable depth and width, along with good surface flatness. Finally, experiments have initially verified that the microtextured PEEK surface may improve biocompatibility and regulate surface wettability to a certain extent.
Wu, Yifan, Wang, Xiaohui, Han, Yujie, Jin, Shuo
Identification and Quantification of PAHs in Gasoline Soot Using ASE-GC-MS/MS2026-99-01107/31/2026
In the present work, a novel method that combines accelerated solvent extraction (ASE) and gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS) was proposed to identify and quantify polycyclic aromatic hydrocarbons (PAHs) in gasoline soot. The n-hexane was employed to extract the target analytes, and the optimal extraction conditions were identified (cycle times = 3, extraction time = 30 min, extraction temperature = 120°C, and extraction pressure = 100 MPa). The extraction efficiency of six analytes was measured to assess the ASE method; the formation mechanism of partial PAHs was discussed, and the 18 PAHs in gasoline soot were studied both qualitatively and quantitatively under the optimal conditions. It was found that our new method reached a high correlation coefficient (between 0.9987 and 0.9997); the limits of quantification (LOQs) (S/N = 6) for these PAHs were between 0.003 and 0.009 ng/mL with a relative standard deviation (RSD) of 2.9–10.6%. Our method demonstrated good performance in determining the target analytes in soot samples, such as gasoline soot, some materials soot, co-combustion soot, gasoline, and materials. The PAHs differences in soot samples containing gasoline and materials soot samples were significant enough to obtain the observed discrimination. The method is an accurate and sensitive quantitative method to identify gasoline residues in soot samples of arson fire.
Liu, Shujun, Cao, Henan, Qi, Lijie, Liu, Yang, Li, Qi
Experimental Study on Suppression of Lithium-Ion Battery Fires Using Clean and Efficient Aqueous Fire Extinguishing Agents2026-99-01337/31/2026
This study investigates the suppression of lithium-ion battery (LIB) fires using composite aqueous extinguishing agents, with a 20 Ah lithium iron phosphate battery as the experimental subject. Based on the functional selection of coverage-isolation and cooling-smothering, three aqueous extinguishing agents, S-E-1, S-E-2, and S-E-3, were designed and developed using hydrocarbon surfactants. The results indicate that all three aqueous fire extinguishing agents can effectively suppress LIB fires. Through a comprehensive evaluation of extinguishing time, cooling rate during extinguishing agent release, and physical and chemical parameters of the extinguishing agents, the optimal formulation was determined to be 2% SDS (sodium dodecyl sulfate), 1% SDBS (sodium dodecyl benzene sulfonate), 3.5% CAB (cocamidopropyl betaine), 1% APG0810 (alkyl polyglycoside), 1% CDEA (coconut oil acid diethanolamine), 0.32% CH4N2O (urea), 1.5% NH4H2PO4 (ammonium dihydrogen phosphate), 0.5% C2H6O2 (glycol), 1.5% Na3PO4 (sodium phosphate), and deionised water, demonstrated the best performance. Reducing the extinguishing time to 14 seconds, a 41.7% reduction compared to pure water, and increasing the cooling rate to 0.816 °C·s^–1, which is 4.4 times that of pure water, with no reignition observed. This work contributes to the theoretical principles needed to engineer next-generation fire suppression materials for lithium-ion batteries that are both efficient and eco-friendly.
Yu, Tao, Zhu, Shunbing, Li, Ke, Zhang, Menglan
Design and Control of a Target Plate Fastener Assembly and Disassembly Actuator for Divertor Maintenance in Fusion Reactors2026-99-01827/31/2026
With the development of controlled nuclear fusion technology, the tokamak device, as the most promising magnetic confinement fusion reactor for advanced engineering applications, requires remote maintenance of its internal components, which has become a key factor affecting both operational efficiency and safety. As a critical component directly exposed to high-temperature plasma, the divertor target plate needs to be periodically replaced and carefully maintained to ensure stable and reliable reactor operation. However, this region is subject to extreme conditions, including high temperature, high vacuum, and intense radiation, making conventional manual maintenance infeasible. This necessitates the development of intelligent and automated teleoperation systems. To address the automated assembly and disassembly requirements of divertor target plates, this study designs an integrated target plate actuator comprising key functional units: a positioning module, a screwing module, a quick-change module, and a passive compliance structure. The actuator achieves rapid and precise alignment with target plate holes, accommodates bolts of different specifications, and exhibits excellent impact resistance. Furthermore, stiffness and mechanical analyses, supported by finite element simulations, verify the actuator’s safety and reliability under high loads and impact forces. To further enhance operational performance, a segmented disassembly and assembly control strategy based on reinforcement learning is proposed, enabling the actuator to adaptively handle torque variations and ensure precise and stable bolt operations. The results demonstrate that the proposed actuator and control strategy significantly improve the accuracy, stability, and efficiency of target plate operations under complex working conditions, providing a reliable solution for automated divertor maintenance in tokamak devices.
Zang, Xizhe, Yu, Xingzu, Cao, Zhangbin
Topology Optimization of Lightweight for Frame Structure of Deep-Sea Mining Vehicle2026-99-01307/31/2026
In order to improve the self-sufficiency rate of key mineral resources in China, it is necessary to develop and research deep-sea mining vehicles to improve the mining capacity of seabed mineral resources. The deep-sea mining vehicle is a heavy-duty underwater robot, and its main frame structure, as a critical component, must be designed to be lightweight to improve payload capacity and mining efficiency. This paper first conducted static analysis for the initial main frame structure. Finite element analysis results indicate that the initial structure fails to meet the strength requirements for lifting and recovery operations. The power index penalty factor was introduced into the topology optimization, which was based on the variable density method. The topology optimization objective was set to minimize structural compliance, with the maximum element stress and volume fraction used as constraints. The optimization process finally obtained the optimal material distribution. According to the results of topology optimization and space requirements of the installed equipment on the deep-sea mining vehicle, the new frame structure of the mining vehicle was re-established in the secondary modelling. According to the results of the analysis, the weight of the frame structure was reduced by 2.9%, and at the same time, the maximum stress was reduced by 57.2%, the maximum displacement was reduced by 47.2%, and the first-order natural frequency was increased by 54%. The strength and stiffness of the frame structure were greatly improved.
Tao, Yichun, Yang, Mingyu
Development and Technical Verification of A Lunar Dust Environment Simulation Mechanism2026-99-01757/31/2026
Lunar dust consists of extremely fine particles and exhibits electrostatic charging properties and electrostatic adhesion. These characteristics cause lunar dust to be highly susceptible to mobilization during lander touchdowns, rover traversals, and human activities, forming widely distributed dust clouds. Lunar dust contamination not only abrades spacecraft and equipment to impair their performance but also poses a threat to astronauts’ safety. To verify the impact of the lunar dust environment on exploration equipment components, a simulation mechanism adaptable to the thermal vacuum test environment was designed. This mechanism is integrated into the lunar environment simulation system and uses a vacuum stepper motor to drive a ratchet mechanism, enabling precise vibrational injection of simulated lunar dust. It mainly consists of a pretreatment mechanism, a particle sedimentation mechanism, a shielding mechanism, and an ultraviolet (UV) irradiation system. Considering the vacuum operating environment, alternating high and low temperature conditions, as well as the strict requirements for the mechanism’s compact size and high reliability, this paper analyzes in detail a series of problems encountered during the development of the mechanism and their corresponding solutions. Stainless steel and polytetrafluoroethylene (PTFE) were selected as the main materials for the mechanism. Meanwhile, active temperature control measures were adopted to actively regulate the temperature of components such as the motor. Ultimately, the mechanism can withstand alternating high and low temperatures ranging from -150°C to 150°C and a vacuum environment of 5 × 10^–6 Pa. Under this environment, the mechanism can achieve vibration frequency adjustment within the range of 1-5 Hz, and realize the sedimentation of simulated lunar dust particles with a particle size of less than 200 μm over an area of 150 mm × 150 mm. After sedimentation, the simulated lunar dust particles can be charged through the photoelectric effect.
Xu, Menglong, Lv, Shizeng, Li, Guohua, Gong, Jie
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
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 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
Study on Cleaning Requirements and Verification Methods for Oxygen Equipment of a Certain Type of Civil Aircraft2026-99-18037/17/2026
Pollution in the oxygen system of civil aircraft may lead to fire accidents, and maintaining the cleanliness of oxygen equipment is the most effective measure to reduce the risk of fire. This paper introduces the cleanliness requirements, cleaning methods, and procedures of oxygen equipment, and combines the cleanliness level requirements of oxygen equipment for a certain type of civil aircraft. By detecting the total weight of Non-Volatile Residue and the size and quantity of particles on the surface of the parts, it verifies whether the specific cleaning process can meet the cleanliness level required by the design. In addition, the possible sources of pollutants are analyzed based on the first unqualified verification results, and targeted improvement directions for the process are provided. After re-performing the cleanliness verification test, the results passed successfully, indicating that the process improvement is effective and has passed the airworthiness certification of the reviewer.
Huang, Jingqi
EUROCAE/SAE WG80/AE-7AFC Hydrogen Fuel Cells Aircraft Fuel Cell Safety GuidelinesAIR6464 (Current)7/17/2026
This document defines the technical guidelines for the safe integration of Proton Exchange Membrane (PEM) Fuel Cell Systems (FCS), fuel (considered to be liquid and compressed hydrogen storage types only), fuel storage, fuel distribution and appropriate electrical systems into the aircraft. Editorial Note: Today PEM systems and fuel storage represent the most mature FCS technology and currently forms the basis for this standard. Other types of fuel cell systems and fuels (including reforming technologies and electrolyzers), may be covered by a further update to this document.
AE-7F Hydrogen and Fuel Cells
Flight Test Methodology for Verification of Precipitation Static Protection in Civil Aircraft Radio Navigation Systems2026-99-18097/17/2026
The verification of Precipitation static (P-static) protection for the radio navigation system of civil aircraft is a critical test item for airworthiness certification. However, determining the presence of P-Static on the aircraft fuselage and assessing whether its discharge interferes with the radio navigation system remains challenging, with testing methods still under exploration. By analyzing airworthiness certification test provisions, the necessity of conducting flight tests for P-static protection verification of the radio navigation system was clarified. Based on existing conditions for civil aircraft flight tests, a comprehensive flight test method was proposed to verify the P-satic protection capability of the radio navigation system. This method includes determining external meteorological conditions, measuring electrostatic parameters, and designing aircraft maneuvers and states. The test plan was validated on a test aircraft. Discharge current data measured on a discharger indicates that during the flight of a civil aircraft through cirrus clouds, negative charge accumulated on the aircraft's surface, leading to electrostatic discharge. The maximum peak discharge current recorded was 330 μA. P-satic radiation field data were obtained near the Automatic Direction Finder (ADF) antenna; the radiation energy is primarily concentrated within the 200 MHz range, with some energy distribution still observed between 200 MHz and 500 MHz. Within the 200 MHz range, the signal amplitude exceeds the background noise, and stable peaks appear at multiple frequency points, with the maximum amplitude reaching up to 50 dBm.confirming the presence of a P-Static environment. This achieved the objective of evaluating the functional performance of the radio navigation system in an electrostatic environment, providing technical support for P-Static protection verification flight tests and offering a reference for the practical application of electrostatic protection design.
Han, Chunyong, Wang, Fusheng
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
Ship Tunnel Navigation Evacuation Simulation and Evacuation Capability Evaluation2026-99-05727/10/2026
In order to solve the ship emergencies that may occur in the process of tunnel navigation, the tunnel pontoon-type bank wall evacuation channel proposed in a large navigation building is taken as the research object. Based on Pathfinder evacuation software, a numerical model of pedestrian evacuation for 500 passenger ships in emergency situations such as fire in the navigation tunnel is established, and the evacuation simulation analysis and evacuation ability evaluation are completed. The analysis shows that the emergency evacuation time of personnel is at least about 21 minutes, and the bottleneck of emergency evacuation equipment for personnel in the navigation tunnel is at the entrance of the pontoon escape. The results provide guidance and suggestions for the design optimization of the evacuation channel of the tunnel bank wall in the later period.
Tao, Ran, Li, Ran, Tang, Weibi, Hu, Zhifang, Qin, Pan
Crashworthiness of WC19 Wheelchairs in Vertical Dynamic Aircraft Seating Tests09-14-02-00047/9/2026
Currently, people who use wheelchairs are not permitted to use their own wheelchairs as seats on commercial aircraft. To advance equitable aircraft travel for these passengers, we need to determine whether wheelchairs would be safe seating for their occupants and not pose a safety hazard for other passengers in case of emergency landing. We hypothesized that wheelchairs meeting the voluntary standards for vehicle crashworthiness (Rehabilitation Engineering Society of North America [RESNA] Section 19 Wheelchairs Used as Seats in Motor Vehicles [WC19]) would be able to pass the Federal Aviation Administration (FAA) vertical crashworthiness standards for aircraft seating. Wheelchairs were secured using surrogate 4-point strap tiedowns using the geometry specified by WC19. The FAA Hybrid III anthropomorphic test device (FH3 ATD) was restrained by both the wheelchair-attached lap belt and a vehicle-mounted lap belt identified as necessary to pass FAA dynamic horizontal test requirements. For the dynamic vertical testing with the wheelchairs oriented 60 degrees relative to horizontal, modeling demonstrated the suitability of using the trapezoidal pulse achieved with the UMTRI sled produced rather than the typical triangular shaped FAA pulse. Of the five manual and three power wheelchairs tested, four had broken components that would not impede emergency exit, four did not have visible damage, and the FH3 remained within the seat in all tests. The three power wheelchairs did not meet lumbar compression requirements. Based on these results, it may be feasible for people to use their own WC19-compliant wheelchairs on aircraft when secured to the aircraft with 4-point strap tiedown systems, supplemented by an occupant lap belt anchored to the aircraft, notwithstanding the lumbar force requirement.
Manary, Miriam A., Orton, Nichole Ritchie, Vallier, Tyler, Boyle, Kyle J., Klinich, Kathleen DeSantis
Rib Design of Electric Drive Unit Housings for Reduced Noise Radiation2026-01-06876/20/2026
Although propulsion noise often constitutes a minority of the overall noise in electric vehicles, it remains an important quality indicator due to its high-frequency tonal character, which is undesirable even at low levels. There are many factors that influence the interior car levels of propulsion noise, i.e. gear whine and electric motor whine. The primary ones to consider are the electric drive units (EDU) internal forces, but also secondary properties such as EDU housing design and encapsulation, vehicle sound pack and mount isolation play important roles. This work focuses on EDU housing design and more particularly on the housing ribs that enables attachment point stiffness and housing strength, but which can also cause problems in terms of noise radiation. Numerical parameter studies on geometrical properties such as length dimensions, thickness and curvature were performed on single ribs of different types. For each design iteration, the key performance indicators radiated sound power, squared velocity and radiation efficiency were studied. The outcome of this work provides insights into which characteristics of ribs that are central for radiated noise. For instance, it was proven that a rather small curvature of the outer edge of a rib can decrease the radiated noise but also that certain rib dimensions can result in extensive noise due to the interaction of the first bending mode with the peak in radiation efficiency.
Lennström, David, Malm, Oskar, wurzinger, Jakob, Cederlund, Johan
Vibroacoustic Analysis and Optimisation of an Electric Refrigerant Scroll Compressor2026-01-07226/20/2026
In electrified vehicles, auxiliary components can represent a dominant source of noise, one of which is the refrigerant scroll compressor. Compared with vehicles equipped with internal combustion engines, electrified vehicles require larger refrigerant compressors, as thermal management is needed not only for the passenger compartment but also for the battery and electric drive components. Excitation mechanisms within the compressor, arising from the cyclic compression process and the eccentric motion of the scroll, induce housing vibrations and result in airborne sound radiation. To investigate the vibroacoustic noise generation mechanisms of a scroll compressor, operational vibrations were analysed using accelerometers and three-dimensional laser scanning vibrometry. In addition, the radiated sound was characterised using microphones and near-field sound intensity measurements. The results demonstrate a strong correlation between surface vibrations and airborne sound radiation, with the vibroacoustic behaviour being dominated by speed-dependent tonal components. Pronounced vibration and sound radiation levels occur when excitation orders coincide with rigid-body modes of the mounting system or structural eigenmodes of the compressor housing. Based on these findings, a constrained-layer damping treatment was applied to selected, highly sound-radiating regions of the compressor housing. Although the overall reduction in sound power was limited due to the high stiffness and predominantly rigid-body behaviour of the housing, local vibration and sound radiation reductions were achieved for structurally flexible components, resulting in a perceptible improvement in subjective sound quality. These results highlight the importance of spatially resolved vibroacoustic analysis for understanding noise generation mechanisms and for guiding targeted optimisation measures for refrigerant compressors.
Saur, Lukas, Beer, Gabriel, Fritzsche, Marco, Becker, Stefan
Guide for Conducting an HIRF and Lightning Safety Assessment (HLSA)ARP8482 (Current)6/15/2026
Highly integrated electrical and electronic systems that perform functions within an aircraft may have potential failure conditions during and after exposure to the High-Intensity Radiated Fields (HIRF) or lightning environments. It is therefore necessary to conduct an HIRF and Lightning Safety Assessment (HLSA) that can identify potential failure conditions resulting from exposure to the aircraft HIRF and lightning environments. The failure conditions, failure conditions classifications, and independence principles identified by Aircraft Functional Hazard Assessment (AFHA), Preliminary Aircraft Safety Assessment (PASA), System Functional Hazard Assessment (SFHA), and Preliminary System Safety Assessment (PSSA), and lessons learned from previous experience, are used to identify proposed requirements during the development process. Ultimately, these requirements will result in a design capable of demonstrating that exposure to the HIRF and lightning environments will not result in adverse effects to the operation of the aircraft. This document provides guidance for conducting the HLSA process to classify the system and its equipment to the appropriate HIRF and Lightning Certification Levels (HLCLs).
AE-4 Electromagnetic Compatibility (EMC) Committee
Identification and Assessment of Damage to Composite Aircraft Structures Training DocumentAIR6825 (Current)6/10/2026
Individuals who complete the applicable modules aligned with this training document will be able to define the type of damage, define the extent of damage, determine if further inspection is required, evaluate the damage against published allowable damage limits, and provide accurate documentation of the damage. The intended outcome of the training is increased safety such that no aircraft is released with unknown damage and that the aircraft meets continued airworthiness requirements. The goal is to change the culture from damage discovery to damage reporting while also reducing or eliminating flight delays due to incorrect or insufficient information. Teaching levels have been assigned to the curriculum to define the knowledge, skills, and abilities graduates will need. Minimum hours of instruction have been provided to ensure adequate coverage of all subject matter including lecture and practical exercise. These minimums may be exceeded and may include an increase in the total number of training hours and/or increases in the teaching levels. The modules are intended to be a competency-based training approach. Each curriculum is a subpart of this document. Module 1 is the Composite Awareness curriculum, independent of the application. Module 2 is the Initial Inspection and Damage Mapping curriculum. Module 3 is the Special Inspection Tools curriculum. Module 4 is the Reporting, Recording, and Assessment curriculum. NOTE: While the modules in this document are technically interrelated, each module can be trained independently; modules may be selected as applicable to an operator’s or maintenance organization’s needs. The combination of the modules represents the applicable identification and assessment process for damage to composite aircraft structures (see Figure 1). Module 1 is prerequisite for attendance to the other modules. The contents of Module 1 may also be used for composite awareness training of a broader target audience, including line mechanics.
AMS CACRC Commercial Aircraft Composite Repair Committee
Numerical Methodology for Aircraft Light Explosion Proofness Study2026-26-07906/1/2026
The increasing demand for safety and reliability in aerospace applications necessitates rigorous testing of aircraft components, including light units, for explosion proofness. Traditional explosion proofness tests are destructive, expensive, and time-consuming, requiring significant resources for test setups and prototypes. To address these challenges, this research presents a numerical methodology using Computational Fluid Dynamics (CFD) simulations to investigate the explosion proofness for aircraft light units. The primary motivation of this study is to establish a computational framework that supports early-stage design screening, reduces the number of physical prototypes, and enhances understanding of explosion behavior before formal qualification testing. This work contributes to advancing engineering practices in the aerospace industry by demonstrating the efficacy of CFD simulations in evaluating and enhancing the explosion proofness of light units. The proposed CFD model, implemented in ANSYS Fluent, adheres to the standards outlined in DO 160 for case setup, ensuring the accuracy and relevance of the simulation results. The methodology involves creating a simulation domain for the light unit, initially containing an air-fuel mixture with a localized high-temperature region to initiate ignition. This setup replicates the conditions of actual explosion proofness tests, providing a realistic assessment of light unit performance This CFD simulation methodology incorporates reduced chemical reaction mechanisms to model the explosion process effectively. By simplifying the chemical reactions involved, the computational load is minimized, making the simulations both accurate and feasible. This approach ensures that the CFD model can provide precise insights into the explosion dynamics while maintaining computational efficiency.
Selvaraj, Sugumaran, Nataraja, Prabhu
Implementation of Wireless IoT Technology for Enhanced Communication and Monitoring in EVAC Slide Emergency Systems2026-26-07926/1/2026
Emergency evacuation slides (EVAC slides) are critical safety devices used on aircraft to enable rapid egress during emergencies. While these slides provide a quick and reliable escape route, communication between separated slides during evacuation remains a challenge. Often, during raft deployment over water, slides may drift apart impeding communication among evacuees and rescue personnel potentially compromising safety. Existing aircraft EVAC systems lack integrated wireless communication relying on visual or voice signals that are unreliable in chaotic conditions. This paper explores the integration of wireless IoT technology into EVAC slide systems to facilitate inter-slide communication and monitor critical parameters such as slide air pressure and the floating weight of stranded passengers through embedded sensors. It proposes the adoption of Long Range (LoRa) modulation technology for wireless communication chosen for its low-power, long-range performance and license-free operation in emergency evacuation scenarios. In addition, the usage of this proposed technology can be further extended to locate the aircraft when other existing locating mechanisms fail.
Sengodan, Rajkumar, Talore, Suresh
Thermo-Structural Analysis of Grid Fins for Re-Entry Modules2026-26-07496/1/2026
Grid fins are non-conventional aerodynamic lifting and control surfaces which are made of a frame supporting lifting surfaces positioned in the form of a lattice structure. Grid fins are also called as lattice fins and are used as control surfaces in launch vehicles, crew escape systems, missiles etc. to achieve static stability. Each panel of the grid fin acts as fin and it produces force which increases stability of the vehicle. For a crew escape system module, grid fins are used as a passive aerodynamic control surfaces to achieve static stability. Grid fins are positioned at the end of crew escape system module to provide required static margin by increasing moment arm. In contrast to conventional fins, grid fins incorporate a distinctive waffle-like pattern or grid pattern configuration, offering superior aerodynamic performance in supersonic regimes and enabling compact storage in stowed position during launch followed by deployment at the time of exigency. In case of an emergency, crew escape system is activated and it will take crew escape module away from the launch vehicle during atmospheric regime. In this scenario, grid fins are deployed simultaneously along with firing of high-thrust, fast-acting solid rocket motors (SRMs) which provide the impulsive force needed for clean separation. Grid fins help to stabilize the crew escape system module by counteracting aerodynamic instabilities, especially when the module is moving through the atmosphere at high speeds. The primary structural loads acting on grid fins include deployment forces (hinge forces, locking), aerodynamic, and inertial forces. Additionally, the exhaust plumes from the firing of SRMs impinge directly upon the grid fins, generating intense thermal loads characterized by rapid temperature gradients and localized heating. The simultaneous presence of thermal and structural loads influences displacements, stresses, interface joints integrity and maximum buckling loads. Furthermore, elevated temperatures degrade mechanical properties such as yield strength, ultimate strength, and Young’s modulus, therefore a thermo-structural analysis is carried out to study the effects of these combined loads on grid fins. This paper presents typical grid fin configuration, thermo-structural formulation, finite element model details, and thermo-structural analysis results including stress margins, deformations, buckling load factors and preload variations for the maximum design load case.
Mali, Somanath Nandu, Sundar Raj, R, Sundaresan, MK, R, Suresh
Edge Computing Advances Enable Smarter Spacecraft and Satellites in Orbit26AERP06_026/1/2026
As satellites take on more onboard processing - from Earth imaging to autonomy - spacecraft computing designers are pushing for higher performance under tight thermal and radiation constraints. Here's how suppliers are approaching heat removal, radiation mitigation and production-scale space-grade computing for LEO and beyond.
Radiation Detection Using Scintillating FibersTBMG-552926/1/2026
Just as the world needs the next generation of nuclear reactors to meet climate goals, it needs new options for safely and securely storing radioactive materials. As of 2022, there were approximately 400,000 metric tons of spent fuel being stored globally, with roughly 90,000 tons in the U.S. alone.
Polymer vs. Metal Seals: A Comparison In Critical Space Systems26AERP06_036/1/2026
Sealing systems in space applications must perform reliably under demanding conditions in engineering: cryogenic temperatures, vibration, leakage control, ultra-high vacuum, ionizing radiation, abrasive particulates, and repeated thermal cycling. Each factor strains conventional sealing technologies. In combination, they can rapidly cause failure in systems where margins are unforgiving and maintenance is impossible. As spacecraft architectures evolve toward longer operational lifetimes and broader mission profiles, sealing requirements continue to tighten. Launch vehicles, satellites, and exploration platforms now operate across wider temperature ranges and in contact with more aggressive propellants and media. As a result, both metal seals and engineered polymer alternatives are evaluated-and selected-against increasingly specific, measurable performance criteria.
Standard Contaminant for Testing Aerospace CleanersAMS7201 (Current)5/27/2026
This specification establishes requirements for a standard contaminant that can be used to represent typical soils encountered in aerospace cleaning. This standard contaminant consists of materials that are common contaminants found in aircraft maintenance depots and manufacturing facilities.
AMS G9 Aerospace Sealing Committee
Mechanism and Experimental Investigation of Variable Stiffness in Soft Actuators Based on Particles Jamming2026-99-07465/15/2026
Soft robot systems demonstrate exceptional load-bearing capacity and spatial compliance during operation, with transformative potential in disaster response scenarios requiring adaptive morphology and hazardous material manipulation. By integrating the complementary advantages of soft robotics and particle jamming mechanisms, this study proposes a real-time variable-stiffness soft actuator, while systematically investigating its mathematical modeling framework and stiffness modulation principles. A deformation model for the variable stiffness soft actuator is established, followed by static analysis of the variable-stiffness members using particle jamming theory, with theoretical investigation of their stress distributions. Subsequently, a variable-stiffness driver was fabricated via additive manufacturing (3D printing), resulting in a flexible mechanical digit capable of stiffness tuning, A soft mechanical hand grasping test platform was built, and grasping experiments of objects of different shapes and sizes were conducted. Experimental validation confirms the influence of actuator dimensions, particle characteristics, and granule size distribution on both stress states and bending angles at the soft robotic digit’s distal segment. The obtained results establish theoretical foundations and advance variable-stiffness soft robotics research and associated stiffness regulation methodologies.
Wang, Jian, Yuan, Haiyang, Deng, Haishun, Chen, Jiaxian
Design of a Novel Intelligent Monitoring Platform for Low and Medium Altitudes2026-99-07395/15/2026
This paper presents the design of a novel intelligent monitoring platform for low and medium altitudes, aiming to offer a new solution for the development of intelligent equipment operating in this airspace. Current monitoring tasks are primarily performed by fixed-wing and multi-rotor UAVs, but these platforms face significant technical bottlenecks in flight endurance and monitoring precision. This research aims to address these deficiencies. The platform is based on a small-scale unmanned airship featuring a semi-rigid, hybrid lift-body structure. Improvements were made upon the traditional ellipsoidal hull; the hull profile was optimized using a geometric superposition method, introducing an aerodynamic camber line with a maximum camber (m) of 4% to enhance aerodynamic performance at small angles of attack. In terms of its energy system, the platform is powered by a purely electric energy system composed of solar panels and batteries; solar energy is used during the day, while surplus energy is stored in the batteries for night operations, thereby effectively extending flight endurance. For intelligent monitoring, the platform integrates an intelligent recognition and positioning system based on machine vision, which is deployed on a Jetson Nano and utilizes a YOLO11 instance segmentation model. The team has experimentally proven that the platform can effectively achieve intelligent monitoring in low and medium altitude airspace. Furthermore, the structural integrity of the gondola and the aerodynamic advantages of the modified hull have also been verified via simulation analysis. This work provides a new design concept for intelligent monitoring equipment. The platform can also be applied to scenarios such as forest fire prevention, precision agriculture, and long-term ecological monitoring, offering a new solution for the design of unmanned intelligent monitoring equipment.
Song, Ziang, Gao, Wenxuan, Cao, Xiaochuan, Zheng, Xing, Zhao, Chong
Fire Prevention on Forestry MachineryJ1212_202605 (Current)5/7/2026
This document applies to off-road forestry work machines defined in SAE J1116 or ISO 6814.
MTC4, Forestry and Logging Equipment
Test Method for Condition in Container of Liquid Organic Coating ComponentsAS7378 (Current)5/6/2026
This test method covers procedures to qualitatively determine the visual and physical condition of a liquid organic coating component (pigmented base, base without pigment, curing solution, or thinner) in a container. Also covered is evaluation of the component container to determine any degradation.
AMS G8 Aerospace Organic Coatings Committee
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