Browse Topic: Axles

Items (1,197)
During a pitch-over event, the forward momentum of the combined bicycle and rider is suddenly arrested causing the rider and bicycle to rotate about the front wheel and also possibly propelling the rider forward. This paper examines the pitch-over of a bicycle and rider using two methods different from previous approaches. One method uses Newton’s 2nd Law directly and the other method uses the principle of impulse and momentum, the integrated form of Newton’s 2nd Law. The two methods provide useful equations, contributing to current literature on the topic of reconstructing and analyzing bicycle pitch-over incidents. The analysis is supplemented with Madymo simulations to evaluate the kinematics and kinetics of the bicycle and rider interacting with front wheel obstructions of different heights. The effect of variables such as rider weight, rider coupling to the bicycle, bicycle speed, and obstruction height on resulting kinematics were evaluated. The analysis shows that a larger
Brach, R. MatthewKelley, MireilleVan Poppel, Jon
As a crucial tool for lunar exploration, lunar rovers are highly susceptible to instability due to the rugged lunar terrain, making control of driving stability essential during operation. This study focuses on a six-wheel lunar rover and develops a torque distribution strategy to improve the handling stability of the lunar rover. Based on a layered control structure, firstly, the approach establishes a two-degree-of-freedom single-track model with front and rear axle steering at the state reference layer to compute the desired yaw rate and mass center sideslip angle. Secondly, in the desired torque decision layer, a sliding mode control-based strategy is used to calculate the desired total driving torque. Thirdly, in the torque distribution layer, the optimal control distribution is adopted to carry out two initial distributions and redistribution of the drive torque planned by the upper layer, to improve the yaw stability of the six-wheeled lunar rover. Finally, a multi-body dynamics
Liu, PengchengZhang, KaidiShi, JunweiYang, WenmiaoZhang, YunqingWu, Jinglai
In future planetary exploration missions, the Eight-Wheeled Planetary Laboratory (EWPL) will have sufficient capacity for tasks but will experience significant lateral slips during high-speed turns due to its large inertia. Modern technology allows for independent steering of all eight wheels, but controlling each wheel's steering angle is key to improving stability during turns. This paper introduces a novel rear-axle steering feed-forward controller to reduce sideslip. First, a mathematical model for the vehicle's steering is established, including kinematic equations based on Ackermann steering. Feed-forward zero side-slip control is applied to the third and fourth axles to counteract the side-slip angle of the center of mass. A multi-body dynamics model of the EWPL is then built in Chrono to evaluate the turning radius and optimize steering angle ratios for the rear axles. Finally, a steady-state cornering simulation on loose terrain compares the performance of the proposed
Liu, JunZhang, KaidiShi, JunweiYang, WenmiaoZhang, YunqingWu, Jinglai
The half vehicle spindle-coupled multi-axial input durability test has been broadly used in the laboratory to evaluate the fatigue performance of the vehicle chassis systems by automotive suppliers and OEMs. In the lab, the front or rear axle assembly is usually held by fixtures at the interfaces where it originally connects to the vehicle body. The fixture stiffness is vital for the laboratory test to best replicate the durability test in the field at a full vehicle level especially when the subframe of the front or rear axle is hard mounted to the vehicle body. In this work, a multi-flexible body dynamics (MFBD) model in Adams/Car was utilized to simulate a full vehicle field test over various road events (rough road, braking, steering). The wheel center loads were then used as inputs for the spindle coupled simulations of the front axle with a non-isolated subframe. Three types of fixtures including trimmed vehicle body, a rigid fixture with softer connections and a rigid fixture
Gao, JianghuaSmith, DerekZhang, XinYu, Xiao
One challenge for autonomous vehicle (AV) control is the variation in road roughness which can lead to deviations from the intended course or loss of road contact while steering. The aim of this work is to develop a real-time road roughness estimation system using a Bayesian-based calibration routine that takes in axle accelerations from the vehicle and predicts the current road roughness of the terrain. The Bayesian-based calibration method has the advantage of providing posterior distributions and thus giving a quantifiable estimate of the confidence in the prediction that can be used to adjust the control algorithm based on desired risk posture. Within the calibration routine, a Gaussian process model is first used as a surrogate for a simulated half-vehicle model which takes vehicle velocity and road surface roughness (GD) to output the axle acceleration. Then the calibration step takes in the observed axle acceleration and vehicle velocity and calibrates the Gaussian process model
Lewis, EdwinaParameshwaran, AdityaRedmond, LauraWang, Yue
A heavy-duty commercial electric truck is equipped with dual axles, with the middle axle driven by an electric motor and a three-speed transmission and the rear axle driven by an electric motor and a two-speed transmission. To consider the dynamic and economy performance of the whole vehicle, as well as the gear distribution characteristics in the vehicle operation, a comprehensive shifting schedule based on the cross-particle swarm algorithm is proposed. By establishing the longitudinal dynamics model of the truck, the optimal power shift schedule and the optimal economics shift schedule of each of the two transmissions are studied. Under the standard test conditions, an optimal gear control strategy based on the dynamic programming algorithm considering the shift interval is proposed, and the shift schedule for the standard conditions is derived through the hierarchical clustering method. Furthermore, with 0-100 km/h acceleration capability and specific energy consumption as the
Guo, JunZhang, YunqingWu, Jinglai
Brake-by-wire systems have received more and more attention in the recent years, but a close look on the available systems shows, that they have not reached full by-wire level yet. Most systems are still using hydraulic connections between main cylinder and the brake calipers on at least one axle to ensure functional safety. Mostly, this is the front axle, since the front brakes have to convert more kinetic energy during braking manoeuvers. Electromechanical actuators are currently used for rear brakes in hybrid brake-by-wire applications solely, since a loss of the front brake calipers can lead to severe conditions and control loss of the vehicle during braking. Further, the higher mass of battery electric vehicles (BEVs) leads to much higher braking forces on both axles and to increased sizes of the electromechanical calipers. This article presents a concept for a brake-by-wire system for battery electric vehicles, which features electromechanical brake actuators on all corners and a
Heydrich, MariusLenz, MatthiasIvanov, ValentinStoev, JulianLecoutere, Johan
As one of the most important design choices in the powertrain design cycle, motor selection is conventionally performed according to given automotive requirements. Motor-related powertrain design parameters like gear ratio, power output ratio between different axles, are excluded from the motor design process. In this paper, three comparative studies are performed to investigate the impact of these motor-related powertrain design parameters on the motor performance and the weight/cost/efficiency of the entire EV powertrain. In the first study, three PM motor designs—characterized by high, medium, and low rated speeds—will be assessed for a two-axle EV using various gear ratio configurations. The same motor design will be used for both axles. In the second study, five motor designs with varying power and ratings (PM, non-PM) but identical rated speeds will be evaluated for a two-axle EV, permitting different power ratings for the front and rear axles. The design trade-offs between motor
Movahed, EhsanGodbehere, JonathanJia, Yijiang
The introduction of autonomous truck platoons is expected to result in drastic changes in operational characteristics of freight shipments, which may in turn have significant impacts on efficiency, energy consumption, and infrastructure durability. Since the lateral positions of autonomous trucks traveling consecutively within a lane are fixed and similar (channelized traffic), such platooning operations are likely to accelerate damage accumulation within pavement structures. To further advance the application of truck platooning technology in various pavement environments, this study develops a flexible evaluation method to evaluate the impact of lateral arrangement within autonomous truck platoons on asphalt pavement performance. This method simplifies the impact of intermittent axle load applications along the driving direction within a platoon, supporting platoon controllers in directly evaluating pavement damage for different platoon configurations. Specifically, a truck platoon
Wenlu, YuYe, QinChen, DaoxieMin, YitongChen, Leilei
This SAE Recommended Practice covers passive torque biasing axle and center differentials used in passenger car and light truck applications. Differentials are of the bevel gear, helical gear, and planetary types, although other configurations are possible.
Drivetrain Standards Committee
This study focuses on machining automobile parts such as drive shafts and axles made of low alloy steel AISI 4140. The influence of cutting inserts geometrical parameters, viz., relief angle (RIA), rake angle (RAA), and nose radius (NA) are studied by designing experiments using Taguchi’s methodology. Numerical simulation is conducted using DEFORM-2D; a suitable L9 orthogonal array (OA) is considered for this work for varying combinations of inputs, and the resultant cutting force, maximum principal stress, and tool life are determined. Adopting a signal-to-noise (S/N) ratio minimizes the outputs for better machining conditions and achieves high-quality components with precision, tolerance, and accuracy. The ideal conditions obtained from the S/N ratio are RAA of 6°, RIA of 3°, and NR of 0.6 mm. Analysis of variance presents that the NR influences the resultant cutting force, wear depth, and work piece damage 73.51%, RAA following by 23.99%, and RIA by 2.03% achieved with a R2 value of
Senthilkumar, N.
Born Electric SUVs generally feature a high centre of gravity (CG) with greater rear axle weight. They use sophisticated multi-link suspension, which offers large scope for ride comfort and handling optimisation. The development costs and time associated with the process will position the vehicle in a premium segment. Usually, the twist beam (RTB) is used in lower rear axle weight category vehicles due to its simple design and cost effectiveness. This study showcases exploration for implementation of RTB on higher weight category vehicles, which usually uses multi-link suspension. The limitation of the twist beam is to exhibit lateral force compliance oversteer during cornering, due to large moment arm from wheel centre to twist beam bush. Lack of lateral stiffness when compared to multi-link suspension causes delayed rear axle yaw response. It also has reduced scope in ride-handling optimization due to its simple structure and kinematics. So, in order to maximize the performance
Prabhakara Rao, VageeshRasal, ShraddheshAsthana, ShivamM, SudhanVellandi, Vikraman
Honda has long been at the cutting edge of mobility and tech, with everything from the Asimo robot of 20 years ago to plans for reusable rockets to launch lightweight satellites into orbit. During a Tech Day event in early October in Tochigi, Japan, the Japanese automaker announced further details of its upcoming Honda 0 architecture (Honda calls it “Honda Zero” but writes it with the number), its first in-house electric platform designed from the ground up. Honda also discussed some of the advanced manufacturing techniques it's pioneering to reach its core design and technology tenants.
Bassett, Abigail
Torsional vibration generated during operation of commercial vehicles can negatively affect the life of driveline components, including the transmission, driveshafts, and rear axle. Undesirable vibrations typically stem from off-specification parts, or excitation at one or more system resonant frequencies. The solution for the former involves getting the system components within specification. As for the latter, the solution involves avoiding excitation at resonance, or modifying the parameters to move the system’s resonant frequencies outside the range of operation through component changes that modify one, or more, component inertia, stiffness, or damping characteristics. One goal of the effort described in this article is to propose, and experimentally demonstrate, a physics-based gear-shifting algorithm that prevents excitation of the system’s resonant frequency if it lies in the vehicle’s range of operation. To guide that effort, analysis was conducted with a numerical simulation
Dhamankar, ShvetaAli, JunaidParshall, EvanShaver, GregoryEvans, JohnBajaj, Anil K.
The objective of the project was to evaluate the energy efficiency of a hybrid electric tractor-semi-trailer combination prototype. The prototype was developed for log hauling application by integrating an existing tractor with an electric semi-trailer to improve fuel consumption and reduce greenhouse gas emissions. One of the conventional axles of the quad axle semi-trailer was replaced with a drive axle powered by an electric motor. Tests were conducted on a 105 km test route with a maximum difference in elevation of 355 m, including a hilly section with a length of 89 km. The results indicated fuel savings ranging from 10.5% to 14% per test run, with an average fuel savings of 12% when the electric drive axle was engaged. The hybrid electric tractor semi-trailer consumed 17.5% less fuel up-hill and 9.4% less down-hill. Throughout each test run, the battery’s state of charge fluctuated, averaging between 88% at the start and 52% at the end. Prior to each run, the batteries were
Surcel, Marius-DorinMercier, SteveBonsi, Adime Kofi
During a recent Bosch tech showcase, we spoke with Joe Dear, engineering manager for electric propulsion systems at Linamar. The Guelph, Ontario-based parts manufacturer is no stranger to building unsung components for the auto industry, including gears, camshafts, connecting rods, and cylinder heads. The Linamar team was demonstrating a modified Ram 2500, a collaboration between Bosch and Linamar, that was outfitted with a prototype electric powertrain and new e-axles: a rigid axle on the rear (with a Bosch motor and inverter) and a steering axle up front.
Blanco, Sebastian
Eaton and BAE Systems have collaborated to create an electric powertrain featuring BAE electronics and an Eaton four-speed transmission. One of the advantages that OEMs have long touted for battery-electric vehicles (BEVs) has been the elimination of components like the transmission. The instant torque that an electric motor can supply often mitigates the need for any sort of torque multiplication beyond what the chosen axle ratio can provide. However, what the industry has found is that this concept has its limitations in certain use cases. When asked to haul heavy loads over sustained grades or at freeway speeds, a direct drive BEV powertrain rapidly begins losing efficiency and range. Of course, batteries and motors can be scaled up to handle heavier loads, but these methods add both cost and weight to vehicles for which these numbers are already major concerns.
Wolfe, Matt
This recommended practice contains dimensions and tolerances for spindles in the interface area. Interfacing components include axle spindle, bearing cones, bearing spacer, and seal. This recommended practice is intended for axles commonly used on Class 7 and 8 commercial vehicles. Included are SAE axle configurations FF, FL, I80, L, N, P, R, U, and W.
Truck and Bus Wheel Committee
The axle, or differential, flange is understood to be a large source of vehicle driveline imbalance, or unbalance, through defining the center of rotation of a driveshaft. The tolerances and methods of manufacturing and assembly are therefore very important. The aim of the current investigation, is to understand and quantify the imbalance contributions from flange radial and axial runout, along with location error between the driveshaft and axle flange. An overview of the measured radial and axial runouts from a population of 100 axle assemblies is presented, including correlation of the imbalance amplitude distributions to some standard probability density functions. It was found from the investigation, that it is important to understand the nature of any source of runout, relative to any subassembly/component-level balancing, in modeling the transfer function from runout to imbalance loading. Methods for calculating the imbalance of an assembled driveline are presented, which include
Leslie, Andrew C.Liew, AndrewBaddeley, VivDent, SolomonMeehan, Paul A.
The axle system is a major contributor for road induced vehicle interior noise. However, it is challenging to characterize the NVH performance of the axle system because it is coupled with both the tire/wheel and the body structure. In this article, we introduce a global approach to control the NVH performance of the axle system. The force transmissibility based on the blocked force concept was defined as the indicator of NVH performance of the axle system. A hybrid method combining test and simulation was developed to assess the intrinsic NVH performance of the axle system. The force transmissibility of the axle system is the blocked force generated by the axle system at the body mounting points with a unit of input force on the wheel. It can be simulated easily by FEM with rigid boundary conditions. However, measuring the blocked forces of the axle system is much more complex because it requires very stiff boundary conditions, which are difficult to realize on a realistic test rig
Wang, ShanjinGagiu, Constantin
Battery-electric vehicles (BEVs) require new chassis components, which are realized as mechatronic systems mainly and support more and more by-wire functionality. Besides better controllability, it eases the implementation of integrated control strategies to combine different domains of vehicle dynamics. Especially powertrain layouts based on electric in-wheel machines (IWMs) require such an integrated approach to unfold their full potential. The present study describes an integrated, longitudinal vehicle dynamics control strategy for a battery electric sport utility vehicle (SUV) with an electric rear axle based on in-wheel propulsion. Especially the influence of electronic brake force distribution (EBD) and torque blending control on the overall performance are discussed and demonstrated through experiments and driving cycles on public road and benchmarked to results of previous studies derived from [1]. It is shown that the approach improves energy efficiency and energy recovery
Heydrich, MariusMitsching, ThomasGramstat, SebastianLenz, MatthiasIvanov, Valentin
A road test on semi-trailers is carried out, and accelerations of some characteristic points on the braking system,axles,and truck body is measured,also brake pressure and noise around the support frame is acquired.The measured data was analyzed to determine the causes of the brake noise, and the mechanism of the noise of the drum brake of semi-trailers during low-speed braking was investigated. The following conclusions are obtained: (1) Brake noise of the drum brake of the semi-trailer at low-frequency is generated from vibrations of the brake shoes, axle, and body, and the vibration frequency is close to 2nd natural frequency of the axle. (2) Brake noise is generated from stick-slip motion between the brake shoes and the brake drum, where the relative motion between the brake drum and the brake shoes is changed alternately with sliding and sticking, resulting in sudden changes in acceleration and shock vibration. A multi-body dynamic model of the semi-trailer is established for
Tang, HaoShangguan, Wen-BinKang, YingziZheng, Jing-YuanLan, Wen-Biao
The thermal behavior of the electric axle is an essential indicator which requires certain attention during the development process. Due to the complexity of heat generation mechanism and heat transfer boundary conditions, it is difficult to accurately predict the axle’s temperature, especially in real driving conditions. In this paper, a comprehensive 1D model is developed to simulate its heat transfer process effectively and accurately. The heat transfer model is developed based on the thermal network method, and the electric axle is divided into thermal mass according to its heat transfer characteristics. The heat generation model, which accounts for meshing loss, bearing loss, churning loss, and windage loss, exchanges heat flux and oil temperature information with the heat transfer model to take into account the effect of lubricating oil temperature on power loss. Meanwhile, 3D simulation is established for the lubricating oil flow inside the axle and the air flow around it, from
Hu, XiaoyuShao, HenghengHou, YuanjingSun, WanyuLiu, HongweiZhang, Lin
To improve the braking energy recovery rate of pure electric garbage removal vehicles and ensure the braking effect of garbage removal vehicles, a strategy using particle swarm algorithm to optimize the regenerative braking fuzzy control of garbage removal vehicles is proposed. A multi-section front and rear wheel braking force distribution curve is designed considering the braking effect and braking energy recovery. A hierarchical regenerative braking fuzzy control strategy is established based on the braking force and braking intensity required by the vehicle. The first layer is based on the braking force required by the vehicle, based on the front and rear axle braking force distribution plan, and uses fuzzy controllers. Achieve one-time distribution of the front axle braking force; the second layer, according to the magnitude of the braking intensity, divides the braking conditions into light braking, moderate braking and emergency braking, and realizes braking under the three
Zhang, Yu
An advanced multi-layer material model has been developed to simulate the complex behavior in case-carburized gears where hardness dependent strength and elastic-plastic behavior is characterized. Also, an advanced fatigue model has been calibrated to material fatigue tests over a wide range of conditions and implemented in FEMFAT software for root bending fatigue life prediction in differential gears. An FEA model of a differential is setup to simulate the rolling contact and transient stresses occurring within the differential gears. Gear root bending fatigue life is predicted using the calculated stresses and the FEMFAT fatigue model. A specialized rig test is set up and used to measure the fatigue life of the differential over a range of load conditions. Root bending fatigue life predictions are shown to correlate very well with the measured fatigue life in the rig test. Also fatigue life predictions are shown to correlate well with validation tests carried out on a full-scale axle
DeJack, Michael A.Tichy, Richard
With the proliferation of electric vehicles in the market, it has become important for Automotive OEMs (Original Equipment Manufacturers) to focus on delivering a higher driving range while also maximizing performance. One approach OEMs are actively considering in meeting this goal is to include a secondary drive axle disconnect into the powertrain which has the potential to improve the overall driving range by about 6-8.3% [4]. This paper outlines the need for a novel controls architecture to make the Powertrain controls software modular and to reduce the development time needed to provide robust powertrain control software. To do this, the electrified powertrain torque controls at STELLANTIS NV takes a decentralized controls architecture approach, by separating the axle disconnect controls subsystem (ADCS) from the primary path of torque controls. The ADCS takes in information such as the desired axle state and controls the axle disconnect actuators to achieve that state. It then
Madireddy, Krishna ChaitanyaVerhun, BrandonXu, ChengyiSha, HangxingTuller, ZacharyPatel, Nadirsh
An experiment is carried out to measure creep groan of a drum brake located in a trailer axle of a truck. The noise nearby the drum brake and accelerations on brake shoes, axle and trailer frame are collected to analyze the occurring conditions and characteristics of the creep groan. A multi-body dynamics model with 1/4 trailer chassis structures is established for analyzing brake component vibrations that generates the creep groan. In the model, the contact force between brake cam and brake shoes, the contact friction characteristics between brake linings and inner circular surface of brake drum, and the properties of chassis structure are included. Dynamic responses of brake shoes, axle and trailer frame during the braking process are estimated using the established model and the responses are compared with the measured results, which validate the model. Three conclusions of measurement and calculation are obtained. (1) The creep groan is usually generated when braking speed is lower
Zheng, Jing-YuanShangguan, Wen-BinTang, HaoLan, Wen-biao
This paper proposes a thorough investigation of steady-state cornering equilibria for cars. Besides equilibria corresponding to normal driving behaviour - herein denoted as stable-normal turn, drifting is attracting increasing attention. When discussing drifting, it is typically assumed that yaw rate and steering angle have opposite signs, i.e. the driver is countersteering, and the rear axle is saturated. Interestingly, another unstable equilibrium is possible, herein referred to as unstable-normal turn. In this work, an attempt to give a comprehensive definition of drift is made. An inverse model is proposed to compute the driver inputs needed to perform a steady-state turn for a given radius and sideslip angle. The mathematical meaning of all equilibria is explored by linearizing the system and analyzing eigenvalues and eigenvectors of the resulting state matrices.
Righetti, GiovanniBinetti, ElisabettaPinto de Castro, RicardoLot, RobertoMassaro, MatteoLenzo, Basilio
This paper presents the characteristics of more than 260 trim levels for over 50 production electric vehicle (EV) models on the market since 2014. Data analysis shows a clear trend of all-wheel-drive (AWD) powertrains being increasingly offered on the market from original equipment manufacturers (OEMs). The latest data from the U.S. Environmental Protection Agency (EPA) shows that AWD EVs have seen a nearly 4 times increase in production from 21 models in 2020 to 79 models in 2023. Meanwhile single axle front-wheel-drive (FWD) and rear-wheel-drive (RWD) drivetrains have seen small to moderate increases over the same period, going from 9 to 11 models and from 5 to 12 models, respectively. Further looking into AWD architectures demonstrates dual electric machine (EM) powertrains using different EM types on each axle remain a small portion of the dual-motor AWD category. However, these architectures have been shown to have energy savings of 1 % to 5 % over that of identical dual-motor
Allca-Pekarovic, AlexanderKollmeyer, PhillipMiddleton, MairiEmadi, Ali
Based on the particularity of the racing field of the Baja SAE China, the Baja Racing Team of our university has adopted rzeppa universal joint for vehicle design and field competition in the semi-axle parts of the race car in previous years. In view of the complex conditions of the Baja Competition, such as gravity test, climb test, handling test, endurance test, etc., it is necessary to optimize and develop a more convenient maintenance model. Installation and use of better performance, more suitable for off-road conditions of the shaft. In this paper, based on the development dynamics of automobile axles and the transverse comparison of various axles, a kind of telescopic cross-shaft universal joint axles is designed by using CATIA software to model and simulate kinematics and dynamics by using ANSYS software. At the same time, the stress and strain of the model are continuously optimized according to the change of axle wheel Angle and the torque matching of Baja Racing. The object
Zhang, HengyuHe, LiXiao, Miaoqi
A chassis is the main skeleton of a go-kart containing distinct components such as the engine, brakes, fuel tank, rear axle, etc. It supports the entire weight and load of the components, so it must be steady enough to withstand shock, twisting, vibration, and other stress. This paper reviews the study carried out on the chassis, highlighting the area where the Nodes, Primary and Secondary members, Horizontal and Vertical members, and Chassis stiffness support the jacking effect with the constraints of maximum Torsional stress, deflection, and critical regions under loading conditions. AISI 4130 is used as the chassis material. When dealing with the software, SolidWorks 2023 and Fusion 360 are used for designing the chassis whereas ANSYS 2022 is used for the analysis of the designed chassis. In order to reduce weight, improve material consumption, and provide an appropriate cross-section, a simulation technique was used in design optimization.
Vignesh, D.Sanchan Kumar, S.Saravanan, V.Sudhakar, M.
Load-carrying transportation has recently increased due to cargo and online home shopping. As a result, there is a growing demand for vehicles that can pass through narrow streets and carry loads for short distances. Electric vehicles are vital in the automotive industry due to their zero emissions and further promotion through new regulations. This study is focused on determining the spring coefficients of helical springs for a micro-truck vehicle, which will be used for cargo transportation and has a leaf spring with a specific spring coefficient on the rear axle and an independent double wishbone suspension system on the front axle. In addition to being vehicles with low weight values, micro-trucks have the axle capacity required for urban transportation due to their low track width and dimensions. Correctly determining the leaf spring is essential as it will directly affect the loads on the suspension system, wheel life, energy consumption, and comfort level. When determining the
Canpolat, BerkanAkbaba, MahirÇifci, ErolDoğan, Mehmet Ali
When a specialty tractor is operated by mounting the front loader or backhoes, the loads are distributed proportionately to the front and rear axles. The maximum load and fatigue life were identified as the main parameters in predicting fatigue failure. This paper mainly focuses on predicting front axle loads and fatigue life in front loader applications. To design a new front axle for the loader application, an existing front axle assembly that was designed for orchard, sprayer, and small farm application is selected for study and to extend it for front loader application with minimal design modifications. The major challenge is to estimate the dynamic loads coming to the front axle due to the front loader application and validate it for a different set of load cases as per the design verification plan. Hence a methodology was framed to estimate the actual loads using MBD, validate with field measurements, and verify the new front axle design using those loads in FEA. This paper
Sekar, PrasanthVaradarajan, SivanesanBalaji, N. T.
The Indian automotive industry is striving towards more safe and durable vehicles. A need was felt to study the effect of changes in axle static loads on fatigue life of the axle components. Also, there was a need to develop generic test method, as there are no test standards or generic methods available in public domain for fatigue testing of commercial vehicle axles. The study was carried out to check direct effect of change in axle loads on various connections on axle, effect of suspension configuration and force distribution, Vehicle dynamics, etc. In this paper, an India specific generic load spectra was evaluated for accelerated laboratory validation. Paper discusses the methodology as; study of heavy commercial vehicle systems, road load data collection on identified test vehicles w.r.t. test matrix finalized, India specific test loads and load spectra development, normalization of axle load spectra w.r.t to static axle weights and arriving at test guidelines. Comprehensive
Kuwar, Virendra SThorat, OmkarBakal, Nikhil RajendraJoshi, Omkar PrakashPawar, Prashant RShinde, Vikram VSutar, MohanPotdar, AnilTak, SachinNilangekar, AbhijitKulkarni, Milind
The electric vehicle market in India has tremendous growth potential in the upcoming years and decades, attracting numerous automotive manufacturers, including Tier-1 suppliers, seeking to participate in this growth phase. Electric powertrains used in e-cars on Indian roads comply with BIS and AIS standards. However, these standards alone do not provide sufficient clarity on the complete list of tests required for developing an e-Axle through all stages of development. Developing the e-Axle in-house for the Indian market poses a significant challenge for OEMs and Tier-1 suppliers, as it will play a crucial role in overall profitability at high volumes in the long term. Adhering solely to the BIS and AIS standards may prove insufficient in fulfilling the developmental prerequisites of an electric axle (e-Axle) system. A comprehensive list of Specific, Measurable, Achievable, Relevant, and Traceable requirements for any e-Axle must be fulfilled through Performance, Functional, Durability
Ray, Rakesh KumarVaither, G V N Selvavindhan
Heavy Commercial Road Vehicles (HCRVs) may be more susceptible to rollover incidents due to their higher centre of gravity position than passenger vehicles, and rollover is one of the significant causes of HCRV accidents. Therefore, variation in vehicle roll behaviour becomes crucial to the safety of an HCRV. Toe misalignment is a commonly observed phenomenon in HCRVs, and studying its impact on roll behaviour is important. In this study, the impact of the symmetric toe and thrust misalignment on the roll behaviour of an HCRV is analysed using IPG TruckMaker®, a vehicle dynamics simulation software. A ramp steer manoeuvre was used for the simulations, and the toe misalignment on a wheel was chosen from the range [-0.21°, 0.21°]. Variation in roll behaviour was quantified using the steering wheel angle at which one-wheel lift-off (OWL) occurred (SWAL). Additionally, an analytical model was formulated to predict OWL and the model predictions were compared with the results from IPG
Chandran, AmarchandGrandhe, RoshanMukhopadhyay, ArkoSharma, MitanshuShankar Ram, C S
Axles are a prominent part of automotive design. Along with a power transmission and differential system, axles support a vehicle’s weight and road-load reactions. Axles carry different attachments such as brakes and suspensions using brackets. Welds play an important role in design and longevity of bracket assemblies. Welds can be susceptible to fractures caused by intrusions akin to cracks and/or discontinuities, compounded by stress concentration due to weld profile and welding processes. Additionally, the simultaneous optimization of both brackets and welds remains a challenge with limited available methods. While topography or shape optimization techniques can enhance bracket robustness by minimizing compliance as the objective, this approach might inadvertently elevate the likelihood of weld fracture if weld dimensions are not concurrently updated. In this endeavor, compliance is used to improve weld life without affecting bracket robustness by using the Vertex Morphing
Wagh, PranavSutar, MohanNilangekar, Abhijit
The Heavy Duty live rear axles in commercial vehicle helps to transmit the drive to the rear wheels and also carries vehicle load. The rear axle along with wheel assembly consists of axle casing, differential unit, half shafts, wheel hub, brake drum, brake chamber and wheels. It is one of the major safety critical element in any commercial vehicle. Based on the suspension type, rear axle housing also carries V rod & radius rod mountings & Spring Seat /Wear pad / Rubber Bolster (in case of bogie suspension). This paper abbreviates the contribution of bogie suspension seating configurations & V-rod Forces on life of heavy duty bogie rear axle casing. In-service DRT hot spot observations were reported on heavy duty rear axle on few models with bogie suspension. In order to find the root cause, devising a proper testing and analysis method is of prime importance. An extensive effort was made to device test methodology based on customer application and field visits. The test methodology
Arumugam, ParamasivamNagarajan, GopikannanN, MahendraMuthu Kumar, Pandurangan
Increased popularity on SUV category in the market has led to high focus on performance attributes of SUVs. Considering high weight & CoG achieving target handling performance is always a challenge. Static Wheel Alignment parameters, especially Camber have shown significant contribution in Handling attributes of vehicle. This paper presents an experimental study on change in wheel camber under the influence of different vehicle loading conditions. In SUVs, generally wheel is subjected to large deflection from its high static loads which makes it quite difficult to maintain an ideal camber angle. Hence, it is important to analyze the camber angle variations under actual loading conditions. An in-house fixture is developed to emulate the actual vehicle loading conditions at rear wheel end. The multi-link rigid axle suspension with watt’s link assembly is mounted on the chassis-frame which is rigidly fixed to ground, and loads are achieved through hydraulic actuators at Wheels. Axle
Jani, HarshilRasal, ShraddheshHussain, InzamamAsthana, ShivamAhire, ManojVellandi, VikramanSenniappan, Moorthy
Climate change due to global warming are major concerns. Electric vehicles are one of the promising technologies to curb the climate change by reducing CO2 emissions significantly. Electric vehicle component selection is a complex process, which has to fulfil multiple requirements with trade-off between performance & efficiency, efficiency & cost, performance & NVH, packaging & performance etc. In addition, E-drive selection in passenger & commercial vehicle is different due to application difference. Hence, it is a great challenge to select right E-Drive comprising motor, MCU and overall gear ratio to meet EV program constraints and targets. This study focuses on criterion used for selecting an E-Drive system comprising motor, MCU and overall gear ratio for electric vehicles in commercial and passenger vehicle segments. The automotive market in India is analysed and the most popular vehicles in CV and PV segments with comparable kerb weights have been identified; small commercial
Jadhav, Vaibhav V.Shendge, Raman S.Warule, Prasad B.Wani, Kalpesh S.
The cost of fuels used for automobile are rising in India on account of high global crude oil prices. The fuel cost constitutes major portion of total cost of operation for Heavy commercial vehicles. Hence, the trend is to carry the goods transport through higher payload capacity rigid/straight trucks that offer lower transportation cost per unit of goods transported. This is driving the design of multi-axle heavy trucks that have lift axles. In addition, improved network of highways and road infrastructure is leading to increase in average operating speed of heavy commercial vehicles. It has made increased focus on occupant as well as road safety while designing the heavy trucks. Hence, the analysis of lift axle suspension from the point of view of vehicle handling and stability is essential. There are two basic kinds of lift axle designs used in heavy commercial vehicles: self-steered lift axle having single tire on each side and non-steered lift axle with dual tires on each side
Vichare, Chaitanya AshokRaval, ChetanPatil, Sudhir
Vehicles equipped with rubber track systems feature a high level of performance but are challenging to design due to the complex components involved and the large number of degrees of freedom, thus raising the need to develop validated numerical simulation tools. In this article, a multibody dynamics (MBD) model of a continuous rubber track system developed in Part 1 is compared with extensive experimental data to evaluate the model accuracy over a wide range of operating conditions (tractor speed and rear axle load). The experiment consists of crossing an instrumented bump-shaped obstacle with a tractor equipped with a pair of rubber track systems on the rear axle. Experimental responses are synchronized with simulation results using a cross-correlation approach. The vertical and longitudinal maximum forces predicted by the model, respectively, show average relative errors of 34% and 39% compared to experimental data (1–16 km/h). In both cases, the average relative error is lower for
Duhamel, OlivierFaivre, AntoinePlante, Jean-Sébastien
This study intends to improve the design of front axles for heavy commercial vehicles, with a major goal of reducing weight while maintaining mechanical strength. The front axle is critical in supporting the weight of the vehicle and facilitating steering while effectively absorbing shocks generated by differences in road surfaces. To achieve these requirements, a front axle beam that minimizes weight, fuel consumption, and stress on the load-carrying member must be designed. In this work, finite element analysis (FEA) techniques are used using CATIA software to assess the structural and mechanical attributes of several front axle designs. The purpose is to pick the best front axle shape depending on specific load situations and driving torque needs. The influence of alternative component shapes on stress and strain distribution is evaluated using surface changes and ANSYS Workbench numerical simulation software. Furthermore, the impact of these structural changes on the mechanical
Sivaraman, P.Ilakiya, P.Prabhu, M.K.Ajayan, AdarshNithyanandan, T.
If a mid-20th century engineer could time travel and see Magna's electric off-road powertrains, they might ask “why is the rear differential so gigantic?” But that's no differential. It's a powerful electric motor fully integrated into each front and rear axle for full 4x4 traction. And Magna said the system will “very likely” be seen on a production vehicle within a few years. At its 2023 tech day presentation, held at a Michigan offroad park and Magna International HQ in Troy, Mich., SAE Media had the opportunity to drive prototype vehicles offroad and sample Magna's in-cabin safety features.
Clonts, Chris
After three years away from the U.S. market with its range-topping SUV, the Land Cruiser, Toyota unveiled the redesigned 2024 Land Cruiser in Salt Lake City on Aug. 1. The model, long known around the world for its durability and offroad credentials, arrives with the SUV competition hotter than ever. The company said the new model will start at around $55,000. The new Land Cruiser has just one engine option, the i-Force Max turbo 2.4-L four-cylinder hybrid that generates 326 hp and 465 lb-ft (630 Nm) that is routed through an 8-speed automatic transmission. All models are equipped with what Toyota classifies as a “full-time four-wheel-drive system” with a lockable center differential and an electronically controlled 2-speed transfer case to impart high- and low-range capability. Also standard is a lockable rear differential to apportion power in a 50/50 ratio across the rear axle.
Clonts, Chris
Vehicle vibration is the key consideration in the early stage of vehicle development. The most dynamic system in a vehicle is the powertrain system, which is a source of various frequency vibration inputs to the vehicle. Mostly for powertrain mounting system design, only the uncoupled powertrain system is considered. However, in real situations, other subsystems are also attached to the powertrain unit. Thereby, assuming only the powertrain unit ignores the dynamic interactions among the powertrain and other systems. To address this shortcoming, a coupled powertrain and driveline mounting system problem is formulated and examined. This 16 DOF problem is constructed around a case of a front engine-based powertrain unit attached to the driveline system, which as an assembly resting on other systems such as chassis, suspensions, axles, and tires. First, the effect of a driveline on torque roll axis and other rigid body modes decoupling is examined analytically in terms of eigensolutions
Singh, JitenderSarna, Amit KumarKumar, NavinSharma, Vikas
Mazda, the automaker with the longest and richest history of using the Wankel rotary engine announced that it resumed mass production of rotary engines for a new variant of the MX-30 compact crossover. Mazda provided little detail about the engine itself, which serves as a generator for the MX-30 e-SKYACTIV R-EV, a plug-in hybrid (PHEV) variant of the MX-30 crossover. Mazda hasn't used the unique powerplant for a production vehicle for more than a decade. The MX-30 e-SKYACTIV R-EV employs the rotary engine in a series-hybrid layout to generate electricity to replenish the vehicle's 17.8-kWh lithium-ion battery, which when fully charged, can provide up to 85 km (31 miles) of driving range on Europe's Worldwide Light Vehicle Test Procedure (WLTP) cycle. Gasoline from a 50-L (13.2-gal.) fuel tank supplies the rotary when its operation is required to provide electricity for extended-range driving. In a release, Mazda explained it “positioned it [the rotary engine] on the same axle as a
Visnic, Bill
Brake-by-wire (BbW) systems are one key technology in modern vehicles. Due to their great potential in the areas of energy efficiency and automated driving, they receive more and more attention nowadays. However, increased complexity and reliance on electric and electrical components in BbW systems bring about new challenges. This applies in particular to the fault tolerance of the brake system. Since drivers cannot form a fallback layer of braking functions due to the mechanical decoupling of the brake pedal, known BbW concepts provide a redundant system layer. However, driving is significantly limited in the event of a failure in the BbW system and is only possible under certain restrictions. The reason for that is a further possible failure (double point of failure scenario), which can result in a significant loss of braking performance. To improve the availability level of the braking functions, a principally new redundancy concept for the double point of failure scenario is
Schlimme, Hauke ChristianHenze, Roman
Articulated vehicles form an important part of our society for the transport of goods. Compared to rigid trucks, tractor-trailer combinations can transport huge quantities of load without increasing the axle load. The fifth wheel (FW) acts as a bridge between the tractor and trailer, which can be moved within the range to achieve rated front and rear axle loads. When the FW is moved front, it adversely affects the cab dynamics and cab suspension forces. Compared to the cab pitch and roll, yaw motion increases drastically. The current study tries to address this issue by providing reaction rod links in the rear cab suspension. In this study, a 4×2 tractor with a three-axle semitrailer is considered by keeping the FW at its frontmost position, which is the worst-case scenario for a cab. Three different cases of reaction rod arrangement and its influence on cab dynamics are studied in comparison with a model without reaction rods. To assess this, time signal–based relative pseudo-fatigue
Bhat, Sindhoor
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