Browse Topic: Bodies and Structures

Items (11,585)
This study aims to develop a lightweight bus passenger seat frame by conducting structural nonlinear finite element analysis (FEA) on various thickness combinations of seat frame components to identify the optimal configuration. The thicknesses of critical structural members that primarily bear the load when force is applied to the seat frame were selected as independent variables, while stress on each component and compliance with ECE R14 seatbelt anchorage displacement regulations were set as dependent variables. A regression analysis was performed to calculate the importance of each component and analyze the influence of each design variable on the dependent variables. Strain gauges were attached to critical areas of the actual seat frame to conduct a seatbelt anchorage test, and simulations under identical conditions were performed using the nonlinear FEA software (LS-DYNA) to validate the reliability of the analysis results. The optimized seat frame exhibited a maximum stress of
Ko, Yeong GookCho, Kyu ChunLee, Ji SunKang, Ki Weon
To comply with the Paris Agreement targets set in 2015, significant reductions in aircraft emissions are required. This demands a fundamental shift in aircraft design. Therefore, it is essential to study how future aircraft designs will affect the integration and design of landing systems. This research project examines the landing gear issues that arise from adopting specific future aircraft configurations. The study focuses on two primary configurations: the high-aspect-ratio wing and the ultra-high-aspect-ratio wing, with selected aircraft concepts from Cranfield University as baselines. It investigates the design and integration of conventional landing systems into these new aircraft concepts, highlighting the limitations posed by the modified airframes. The selected concepts include either telescopic or trailing arm arrangements, with attachment points on the wings or fuselage. A methodology for preliminary sizing of landing systems is presented, emphasizing automation and
Martin, RaphaëlStockford, JackSmith, Howard
Outdoor test facilities for light vehicle exterior noise regulatory measurement need to have surfaces certified to meet ISO 10844. A recent study considered plug-in-hybrid vehicles operating purely in electric mode to compare results at two facilities, both certified. This emphasizes the pavement contribution. Overall results are generally similar, with a few differences which are discussed.
Sorenson, SteveShao, Guangxin
Rattling noise from electrical sound systems is becoming one of the prominent issues for automakers as it directly affects the perception of customers about vehicle quality. Recently, quality sound system is prerequisite for automotive passenger vehicles. And, in the whole systems subwoofer forms dominant part of sound output. However, subwoofer rattle noise problems sometimes occur in small and midsize Sports Utility Vehicles (SUV). Mainly rattle is noise resulting from physical contact of two parts due to vibrations when relative displacement is bigger than gap of two parts, it occurred certain frequency (Between F1~F2), which is main excitation range of subwoofer. In this study, we analyze the subwoofer structural vibration analysis for five sample vehicles based on the test and correlation. However, the present subwoofer system model has limitation in determining the level of this rattle noise. Therefore, this paper discusses how to correlate subwoofer model, frequency
Thota, JagadeeshChoi, SeungchanPark, Jong-Suh
A good Noise, Vibration, and Harshness (NVH) environment in a vehicle plays an important role in attracting a large customer base in the automotive market. Hence, NVH has been given significant priority while considering automotive design. NVH performance is monitored using simulations early during the design phase and testing in later prototype stages in the automotive industry. Meeting NVH performance targets possesses a greater risk related to design modifications in addition to the cost and time associated with the development process. Hence, a more enhanced and matured design process involves Design Point Analysis (DPA), which is essentially a decision-making process in which analytical tools derived from basic sciences, mathematics, statistics, and engineering fundamentals are used to develop a product model that better fulfills the predefined requirement. This paper shows the systematic approach of conducting a Design Point Analysis-level NVH study to evaluate the acoustic
Ranade, Amod A.Shirode, Satish V.Miskin, AtulMahamuni, Ketan J.Shinde, RahulChowdhury, AshokGhan, Pravin
Wind noise is one of the largest sources to interior noise of modern vehicles. This noise is encountered when driving on roads and freeways from medium speed and generates considerable fatigue for passengers on long journeys. Aero-acoustic noise is the result of turbulent and acoustic pressure fluctuations created within the flow. They are transmitted to the passenger compartment via the vibro-acoustic excitation of vehicle surfaces and underbody cavities. Generally, this is the dominant flow-induced source at low frequencies. The transmission mechanism through the vehicle floor and underbody is a complex phenomenon as the paths to the cavity can be both airborne and structure-borne. This study is focused on the simulation of the floor contribution to wind noise of two types of vehicles (SUV and Sports car), whose underbody structure are largely different. Aero-Vibro-acoustic simulations are performed to identify the transmission mechanism of the underbody wind noise and contribution
Mordillat, PhilippeZerrad, MehdiErrico, Fabrizio
Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB
Xu, ChuanyanWang, JianjunXing, QisenChen, HengbinHuang, Xianli
Mechanical light detection and ranging (LiDAR) units utilize spinning lasers to scan surrounding areas to enable limited autonomous driving. The motors within the LiDAR modules create vibration that can propagate through the vehicle frame and become unwanted noise in the cabin of a vehicle. Decoupling the module from the body of the vehicle with highly damped elastomers can reduce the acoustic noise in the cabin and improve the driving experience. Damped elastomers work by absorbing the vibrational energy and dispelling it as low-grade heat. By creating a unique test method to model the behavior of the elastomers, a predictable pattern of the damping ratio yielded insight into the performance of the elastomer throughout the operating temperature range of the LiDAR module. The test method also provides an objective analysis of elastomer durability when exposed to extreme temperatures and loading conditions for extended periods of time. Confidence in elastomer behavior and life span was
Russell, CaseyMasterson, PeterO'Connell, Kerry
Exterior noise (EN) regulations for earth-moving machines (EMMs) require original equipment manufacturers (OEMs) to develop noise mitigation solutions early in the design process. Predicting the effectiveness of these solutions at this stage, however, is challenging. Excavators differ from other EMMs due to their rotating upper frame, which operates atop a fixed lower frame. Regulations such as ISO 6395 and EC/2000/14 mandate specific operating maneuvers, where noise sources dynamically change their position, directivity, and speed throughout the operating cycle. This complexity makes noise contribution analysis more difficult, as it must account for variations in angular position and operating conditions. While previous studies successfully applied Acoustic Source Quantification (ASQ) and contribution analysis to linearly moving EMMs, the angular motion of an excavator’s cab with respect to fixed target microphones introduces additional data processing challenges. This study addresses
Vesikar, Prasad BalkrishnaChaduvula, PrasannaAquino Arriaga, Adrian AntonioHaynes, TimothyDrabison II, John
High-frequency whine noise in electric vehicles (EVs) is a significant issue that impacts customer perception and alters their overall view of the vehicle. This undesirable acoustic environment arises from the interaction between motor polar resonance and the resonance of the engine mount rubber. To address this challenge, the proposal introduces an innovative approach to predicting and tuning the frequency response by precisely adjusting the shape of rubber flaps, specifically their length and width. The approach includes the cumulation of two solutions: a precise adjustment of rubber flap dimensions and the integration of ML. The ML model is trained on historical data, derived from a mixture of physical testing conducted over the years and CAE simulations, to predict the effects of different flap dimensions on frequency response, providing a data-driven basis for optimization. This predictive capability is further enhanced by a Python program that automates the optimization of flap
Hazra, SandipKhan, Arkadip
Sound source identification based on beamforming is widely used today as a spatial sound field visualization technology in wind tunnel experiments for vehicle development. However, the conventional beamforming technique has its inherent limitation, such as bad spatial resolution at the low frequency range, and limited system dynamic range. To improve the performance, three deconvolution methods CLEAN, CLEAN-SC and DAMAS were investigated and applied to identify wind noise sources on a production car in this paper. After analysis of vehicle exterior wind noise sources distribution, correlation analysis between identified exterior noise sources and interior noise were conducted to study their energy contribution to vehicle interior. The results show that the algorithm CLEAN-SC based on spatial source coherence shows the best capability to remove the sidelobes for the uncorrelated wind noise sources, while CLEAN and DAMAS, which are based on point spread functions have definite
He, YinzhiShen, HenghaoWu, YuZhang, LijunYang, ZhigangBlumrich, ReinhardWiedemann, Jochen
When a vehicle is driven at high speed, there exists intricate flow pattern and vortex shedding at the side window area with intense pressure fluctuation. A significant dynamic pressure difference between the vehicle's exterior and interior can render the side window sealing system vulnerable to aspiration. This susceptibility can lead to the generation of leakage noise, adversely affecting acoustic comfort in the vehicle's cabin. This paper delves into the aspiration properties of glassrun seal system under time-varying pressure difference. A nonlinear finite element model of the glassrun seal was established to simulate the quasi-static deformation of the sealing strip during installation process, which aims to obtain the deformed geometric shape and residual stress after this process. Then, the exterior flow field of the glassrun sealing area of a simplified vehicle model was calculated with CFD simulation to obtain the hydrodynamic pressure excitation acting on the outer surface of
Li, HanqiHe, YinzhiZhang, LijunZhang, YongfengYu, WuzhouJiang, ZaixiuBlumrich, ReinhardWiedemann, Jochen
Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from
Rittenschober, Thomas
Based on the objective and subjective experiment and finite element analysis, the influencing factors on the door closing sound quality of a heavy truck is analyzed and optimized. Results show that the loudness and sharpness can be reduced by increasing stiffness and damping of the door. The sound quality can be enhanced by increasing the pressure release area, which can decrease the air pressure resistance of dooring closing. By adding holes on the inner liner and changing the pressure release location, the dooring closing air pressure resistance is reduced from 289 Pa to 181 Pa. In terms of the rebound sound, the sound level is positively related to the door closing force. Increasing the protrusion height and decreasing the stiffness of the vibration absorber of the handle can improve the rebound sound quality. Optimizing the absorbers on both ends of the handle and adding damping material can decrease the loudness by 47.8%, reduce the cavity sound, reduce the rattle and improve the
Wang, JianZhang, YongshenFeng, LeiXie, ChenhaoLin, JieweiSun, Changchun
The arrangement of error microphones for a vehicle active noise control (ANC) system is no trivial work, especially for heavy-duty trucks, due to the dilemma resulted from the large volume of the cab and the limited number of microphones accepted by most manufacturers in the auto industry. Although some pioneering work has laid the foundation for the application of numerical methods exemplified by the genetic-algorithm (GA) to optimize the error sensor arrangement in an ANC system, most ANC developers still resort to trial and error in practice, which is not only a heavy workload given the amount of interested working conditions to be tested, but also does not guarantee to yield the optimum noise cancellation performance. In this paper, the authors designed and implemented an error microphone selection process using a genetic-algorithm (GA) -based mechanism. The target vehicle was a heavy-duty truck with a six-piston diesel engine, and two application scenarios were particularly
Wang, JianLing, ZihongZhang, ZheCai, DeHualv, XiaoZhang, MingGao, GuoRan
This study focuses on the numerical analysis of weather-strip contact sealing performance with a variable cross-sectional design, addressing both static and dynamic behaviors, including the critical issue of stick-slip phenomena. By employing finite element modeling (FEM), the research simulates contact pressures and deformations under varying compression loads, DCE (Door Closing Efforts) requirements, typical in automotive applications. The analysis evaluates how changes in the cross-sectional shape of the weather-strip affect its ability to maintain a consistent sealing performance, especially under dynamic vehicle operations. The study also delves into stick-slip behavior, a known cause of noise and vibration issues, particularly improper/ loosened door-seal contact during dynamic driving condition. This study identifies key parameters influencing stick-slip events, such as friction coefficients, material stiffness, surface interactions, sliding velocity, wet/dry condition
Ganesan, KarthikeyanSeok, Sang HoSun, Hyang Sun
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document establishes performance requirements, design requirements, and design guidelines for electronic devices.
Test Methods and Equipment Stds Committee
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document provides standardized laboratory tests, test methods and equipment, and requirements for lighting devices covered by SAE Recommended Practices and Standards. It is intended for devices used on vehicles less than 2032 mm in width. Tests for vehicles larger than 2032 mm in overall width are covered in SAE J2139. Device-specific tests and requirements can be found in applicable SAE Technical Reports.
Test Methods and Equipment Stds Committee
Performing highly representative tests of aircraft equipment is a critical feature for gaining utmost confidence on their ability to perform flawlessly in flight under the entire spectrum of operating conditions. This can also contribute to accelerate the certification process of a new equipment. A research project (E-LISA) was performed in recent years, as part of the European funded Clean Sky 2 framework, with the objective of building an innovative facility for testing an electrically actuated landing gear and brake for a small air transport. The project eventually led to the development and construction of an Iron Bird able to reproduce in a realistic and comprehensive way a full variety of landing test cases consistent with certification specifications and landing histories available in the repository of the airframer. The Iron Bird that was eventually developed is a multi-functional intelligent and easy reconfigurable facility integrating hardware and software allowing to perform
De Martin, AndreaBertolino, AntonioJacazio, Giovanni
This study presents empirical modifications of Blade Element Momentum Theory (BEMT) to improve rotor performance prediction for open rotors in hovering conditions. The empirical adjustments were made to the inflow ratio, factoring in the real rotor wake area and estimated induced power losses. A comparison between experimental data and two analytical models, one using an empirical inflow formula and the other a theoretical formula (classical BEMT), was conducted for two rotors. The empirical inflow model demonstrated superior accuracy in predicting thrust and torque. These modifications are applied to the inflow ratio by accounting for the actual rotor wake area and estimated induced power losses. The findings highlight the potential for more accurate performance prediction through the integration of empirical data into theoretical frameworks.
Dayhoum, AbdallahRamirez-Serrano, AlejandroMartinuzzi, Robert
Helicopter vibrations, primarily generated by the main rotor-gearbox assembly, are a major source of concern due to their impact on structural integrity, cockpit instrument durability, and crew comfort. These vibrations are mainly transmitted through the gearbox’s rigid support struts to the fuselage, leading to increased cabin noise and potential damage to critical components. This paper presents a solution for vibration mitigation which involves replacing traditional gearbox support struts with low-weight, high-performance active dampers. Developed by Elettronica Aster S.p.A., these active dampers are designed as electro-hydraulic actuators embedded within a compliant structure. The parallel nested configuration of the system enables high power densities and effective vibration control, significantly reducing the transmission of harmful vibrations to the fuselage. The comprehensive model-based design process is detailed, describing the development and use of a high-fidelity physics
Bertolino, Antonio CarloSorli, MassimoPorro, Paolo GiovanniGalli, Claudio
Traditional silicon-based solar cells are completely opaque, which works for solar farms and roofs but would defeat the purpose of windows. However, organic solar cells, in which the light absorber is a kind of plastic, can be transparent.
Polymer composites, such as fiber-reinforced plastics (FRPs), are widely used in shipbuilding, aerospace, and automobile industries due to their lightweight and high strengths. In real-world conditions, ship hulls are exposed to harsh environmental factors, including variations in moisture and salinity. FRPs tend to absorb water and moisture, leading to an increase in weight and a reduction in strengths over time, which is undesirable for ship and aircraft structures. This study investigates the reduction in energy absorption and specific energy absorption of glass FRPs (GFRP) and aluminum honeycomb sandwich composites (AHSC) due to exposure to moisture and salinity. Experimental analysis was conducted by immersing the materials in saline and non-saline water. A comparative assessment of the percentage reduction in specific energy absorption (SEA) of GFRP and AHSC is presented. Additionally, the influence of honeycomb parameters such as cell size (CS), foil thickness (FT), and core
Rajput, ArunKumar, AshwinSunny, Mohhamed RabiusChavhan, Harikrishna
Wind noise is an important indicator for evaluating cabin comfort, and it is essential to accurately predict the wind noise inside the vehicle. In the early stage of automotive design, since the geometry and properties of the sealing strip are often unknown, the contribution of the sealing strip to the wind noise is often directly ignored, which makes the wind noise obtained through simulation in the pre-design stage to be lower than the real value. To investigate the effect of each seal on wind noise, an SUV model was used to simulate the cases of not adding body seals, adding window seals, and further adding door seals, respectively. The contribution of each seal to wind noise was obtained and verified by comparing it with the test results. The influence of the cavity formed at the door seal was also addressed. In the simulations, a CFD solver based on the lattice Boltzmann method (LBM) was used to solve the external flow field, and the noise transmitted into the interior of the
Zhang, YingchaoHe, TengshengWang, YuqiNiu, JiqiangZhang, ZheShen, ChunZhang, Chengchun
Traffic flow prediction is very important in traffic-related fields, and increasing prediction accuracy is the primary goal of traffic prediction research. This study proposes a new traffic flow prediction method, which uses the CNN–BiLSTM model to extract features from traffic data, further models these features through GBRT, and uses Optuna to tune important hyperparameters of the overall model. The main contribution of this study is to propose a new combination model with better performance. The model integrates two deep learning models that are widely used in this field and creatively uses GBRT to process the output features of the front-end model. On this basis, the optimal hyperparameters and the robustness of the model are deeply explored, providing an effective and feasible solution to the difficult problems in traffic flow prediction. This model is experimentally studied using three different data transformation methods (original data, wavelet transform, Fourier transform
Ma, ChangxiJin, Renzhe
This paper describes a three-dimensional structure of an adjustable field magnetization permanent magnet (PM) motor and a high-power density rotor structure with asymmetric permanent magnet arrangement for both high torque and high efficiency operation in the high speed and low torque range. 3D-FEA has confirmed that it is possible to achieve both high torque density and adjustable field magnetization. Load testing using the prototype proposed motor confirmed that high motor efficiency can be achieved even during high-speed operation.
Hiyoshi, YutaroDoi, KotaroNoguchi, Toshihiko
The windscreen is one of the key elements to enhance passenger comfort of touring motorcycle. The clarity through the windscreen should not discomfort the rider. The discomfort we discuss here mainly refers to three factors: the “distortion,” the “blur,” and the “transparency.” Introduced in this paper is the technical measures to achieve sufficient clarity by the injection molding method. Firstly, with respect to the “distortion,” we determined the main cause was local unevenness of plate thickness. As the uneven thickness were related to the accuracy of the die, we clarified the tolerable zone and carried out higher precision machining of the die to satisfy the requirements. Regarding the “blur,” we analyzed the refractive power of the windscreen and found the main cause of blur is the microscopic roughness on the surface. As the microscopic roughness were attributable to the die surface, we clarified the tolerable zone and established the polishing conditions satisfactory for the
Yamada, AtsushiEndo, Sakae
The weave mode of a motorcycle is known to be affected by the flexibility of the vehicle frame. The weave mode has been shown to be more unstable in the 10-DOF model than in the 4-DOF model. However, it is not clear why the weave mode would be unstable, given the six different frame flexibilities. In this study, the authors analyzed the stability of the weave mode in a 4-DOF model when the same was integrated with two types of frame flexibilities. In the vehicle specifications used in the analysis, the combination of the bending flexibility of the front forks and the torsional flexibility of the main frame destabilizes the weave mode. The analysis results show that the phase delay of the front tire lateral force is caused by the phase delay of the steering angle. The combined bending flexibility of the front forks and the torsional flexibility of the main frame results in a large phase lag in the steering angle.
Haraoka, ReiyaKatayama, TsuyoshiYoshino, Takahiko
The arc welding process is essential for motorcycle frames, which are difficult to form in one piece because of their complex shapes, because a single frame has dozens of joints. Many of the damaged parts of the frames under development are from welds. Predicting the strength of welds with high reliability is important to ensure that development proceeds without any rework. In developing frames, CAE is utilized to build up strength before prototyping. Detailed weld shapes are not applicable to FE models of frames because weld shapes vary widely depending on welding conditions. Even if CAE is performed on such an FE model and the evaluation criteria are satisfied, the model may fail in the actual vehicle, possibly due to the difference between CAE and actual weld bead geometry. Therefore, we decided to study the extent to which the stresses in the joint vary with the variation of the weld bead geometry. Morphing, a FE modeling method and design of experiment method, was utilized to
Hada, YusukeSugita, Hisayuki
The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on
Chiou, Yi-HauHwang, Hsiu-YingHuang, Liang-Yu
In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn
Haraguchi, TetsunoriKaneko, Tetsuya
This Aerospace Information Report (AIR) will examine considerations relative to the use of mechanical switches on aircraft landing gear, and present "lessons learned" during the period that these devices have been used.
A-5B Gears, Struts and Couplings Committee
The scope of the test method is to provide stakeholders including fluid manufacturers, airport operators, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This simple test is only designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions. It is not possible to set a general acceptance threshold oxidation limit based on this test method because carbon brake stack oxidation is a function of heat sink design and the operating environment.
A-5A Wheels, Brakes and Skid Controls Committee
This SAE Recommended Practice applies to functions of motor vehicle signaling and marking lighting devices which use light emitting diodes (LEDs) as light sources. This report provides test methods, requirements, and guidelines applicable to the special characteristics of LED lighting devices. This SAE Recommended Practice is in addition to those required for devices designed with incandescent light sources. This report is intended to be a guide to standard practice and is subject to change to reflect additional experience and technical advances.
Signaling and Marking Devices Stds Comm
This SAE Aerospace Recommended Practice (ARP) provides the recommended procedure for obtaining desired preloads in aircraft wheel tie bolts when mounting tires and assembling the wheel. It is generally referred to as the snug-angle bolted joint assembly procedure. It is also known as the “torque-turn” procedure in the heavy equipment ground vehicle industry.
A-5A Wheels, Brakes and Skid Controls Committee
This SAE Aerospace Information Report (AIR) provides information on the parking brake system design for a variety of aircraft including part 23, 25, 27, and 29. The document includes a discussion of key technical issues with parking brakes. This document does NOT provide recommended practices for parking brake system design.
A-5A Wheels, Brakes and Skid Controls Committee
This SAE Aerospace Recommended Practice (ARP) is intended to provide guidance on verifying the integrity of inflation pressure sealing systems of aircraft wheel/tire assemblies.
A-5A Wheels, Brakes and Skid Controls Committee
This SAE Aerospace Recommended Practice (ARP) establishes a procedure for disposition of aircraft wheels that have been involved in accidents/incidents or have been exposed to overheat conditions or overload conditions from loss of adjacent tire pressure (paired wheels) or wheel tie bolts.
A-5A Wheels, Brakes and Skid Controls Committee
This article analyses the fundamental curving mechanics in the context of conditions of perfect steering off-flanging and on-flanging. Then conventional, radial, and asymmetric suspension bogie frame models are presented, and expressions of overall bending stiffness kb and overall shear stiffness ks of each model are derived to formulate the uniform equations of motion on a tangent and circular track. A 4 degree of freedom steady-state curving model is formulated, and performance indices such as stability, curving, and several parameters including angle of attack, tread wear index, and off-flanging performance are investigated for different bogie frame configurations. The compatibility between stability and curving is analyzed concerning those configurations and compared. The critical parameters influencing hunting stability and curving ability are evaluated, and a trade-off between them is analyzed. For the verification, the damped natural frequencies and mean square acceleration
Sharma, Rakesh ChandmalSharma, Sunil KumarPalli, SrihariRallabandi, Sivasankara RajuSharma, Neeraj
The New Car Assessment Program (e.g., US NCAP and EuroNCAP) frontal crash tests are an essential part of vehicle safety evaluations, which are mandatory for the certification of civil means of transport prior to normal road exploitation. The presented research is focused on the behavior of a tubular low-entry bus frame during a frontal impact test at speeds of 32 and 56 km/h, perpendicular to a rigid wall surface. The deformation zones in the bus front and roof parts were estimated using Ansys LS-DYNA and considered such factors as the additional mass (1630 kg) of electric batteries following the replacement of a diesel engine with an electric one. This caused stabilization of the electric bus body along the transverse axis, with deviations decreased by 19.9%. Speed drop from 56 to 32 km/h showed a reduction of the front window sill deformations from 172 to 132 mm, and provided a twofold margin (159.4 m/s2) according to the 30g ThAC criterion of R80. This leads to the conclusion about
Holenko, KostyantynDykha, AleksandrKoda, EugeniuszKernytskyy, IvanRoyko, YuriyHorbay, OrestBerezovetska, OksanaRys, VasylHumeniuk, RuslanBerezovetskyi, SerhiiChalecki, Marek
Headliners are one of the largest components inside an automobile, stretching from the front windshield to the rear windshield. Besides its aesthetic purpose, it contributes to multiple other purposes like housing different components, helps in NVH, defines the interior roominess, and plays a crucial role in defining the deployment of curtain airbag. The headliner also plays a role in meeting regulatory requirements like upward visibility and headroom requirements of the occupants. During the deployment of curtain airbag, it is important that the headliner-pillar interface aids in the easy opening of airbag, with the least hindrance. This is defined by multiple factors like the location of headliner-pillar interface, its distance from the airbag ramp bracket, the position of the inflator, the mountings of the headliner and pillar trims, to name a few. Also, during the deployment of the airbag, it is important that parts such as grabhandle, speaker grilles, etc which are fitted on the
Sabesan, Arvind KochiD., AnanthaKakani, Phani Kumar
This paper addresses the need for improved material selection in parcel shelves, a key component in passenger vehicles used to conceal the trunk area. The focus is on weight optimization, structural integrity, and perceived quality improvement using sustainable and ultra-lightweight composite materials. Traditional materials such as PET Woodstock, while durable, contribute significantly to vehicle weight, which is a drawback in the context of electric vehicles (EVs). The proposed composite material alternatives offer a high strength-to-weight ratio and have been shown to improve the load vs. deflection ratio, enhance aesthetics, and reduce manufacturing complexity and costs. This study outlines the testing and evaluation process of varying GSM and thicknesses of composite materials, demonstrating superior stiffness, reduced deflection under load, and enhanced ease of assembly. This work contributes to the ongoing efforts to achieve lightweighting, cost efficiency, and sustainability in
Kinthala, Nareen KumarPatnaik, MangaKhandelwal, MohitKakani, Phani KumarPalaniappan, Elavarasan
An efficient and safe aircraft scheduling scheme is of great significance to the construction of smart airports. The towbarless aircraft taxiing system (TLATS) is a common dispatching method, which is composed of the towbarless towing vehicle (TLTV) and the aircraft. The system’s trajectory planning and autonomous steering control are being researched in order to improve steering accuracy, dispatching efficiency, and safety. In this article, the towbarless aircraft taxiing system is transformed into tractor-trailer system, the kinematic model and the dynamic model of the aircraft-tractor are established. Taking TLTV as a virtual subsystem of TLATS, and it is regarded as the controlled object of path planning and tracking. In response to the operational requirements of TLTV, an advanced A-star(A*) path planning algorithm is proposed to perform collision avoidance and turn radius restrictions during path planning resulting in a reference path for TLATS. Considering the estimation
Zhu, HengjiaZhao, ZhouqiaoXu, YitongZhang, Wei
Nonlinearities in mechanical systems pose significant challenges for efficiently solving multi-body dynamics (MBD) problems. Although simulations of traditional mechanisms with perfect joints can be performed efficiently, joints in practical applications are often characterized by clearances, leading to reduced simulation efficiency and accuracy. Improving solver effectiveness is essential for simulating systems with nonlinearities. This paper explores the use of Julia, a high-performance open-source programming language, to solve MBD problems formulated as index-1 differential-algebraic equations (DAEs). Euler parameters (quaternions) are employed to represent the orientation of rigid bodies. To illustrate the method's adaptability in addressing non-standard joint types, both perfect and imperfect (with clearance or friction) planar roller guide joints are modeled alongside common perfect joints. A case study of a vehicle sliding door system is presented. The numerical results are
Tong, JiachiMeng, DejianLian, YuboGao, YunkaiYang, James
Physical testing is required to assess multiple vehicles in different conditions, specially to validate those related to regulations. The acoustic evaluations have difficulties and limitations in physical test; cost and time represent important considerations every time. Additionally, the physical validation happens once a prototype has been built, this takes place in a later phase of the development. Sound pressure is measured to validate different requirements in a vehicle, horn sound is one of these and it is related to a regulation of united nations (ECE28). Currently the validation happens in physical test only and the results vary depending on the location of the horn inside the front end of every vehicle. [7] In this article, the work for approaching a virtual validation method through CAE is presented with the intention to get efficiency earlier in product development process.
Alonso, LilianaCruz, RacielAlvarez, Ezequiel
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