Display:

Results

Viewing 121 to 150 of 10887
2017-01-10
Technical Paper
2017-26-0292
Irshad Mahammad, Vinay Nagaraj, Saurabh Prabhakar
Abstract To replicate on-road brake test cycle of cooling or heating through Computational Fluid Dynamics (CFD) simulations, the vehicle model with brake assembly must be solved in transient mode. However, such simulations require significant computational time owning to the physics involved in computing the variation of temperature with time. A methodology developed using commercial CFD tools to predict the Heat Transfer Coefficient (h), Cooling Coefficient (b) and rotor temperatures is described in this paper. All the three modes of heat transfer: conduction, convection and radiation are considered in the current method. Heat transfer coefficients from the CFD simulations are exported to Computer Aided Engineering (CAE) tools to validate the Brake Rotor Thermal Coning caused by high thermal gradients in brake rotor.
2017-01-10
Technical Paper
2017-26-0363
Sathyadevi Jayaraman
Abstract The Insurance Institute for Highway Safety (IIHS) Small Overlap Frontal (SOF) impact assessment program is one of the latest challenges for the automotive development. The SOF load bypasses the primary crumple zone structure and concentrating the force in the front wheel, suspension and firewall - areas not traditionally designed to absorb and dissipate crash energy. Design changes of architectural components at later stages of product development is very difficult and expensive. This paper deals with the procedure to improve SOF performance through CAE as well as to develop the physical test cart to avoid the full vehicle SOF test. CAE procedure developed on chassis subsystem level to validate the SOF performance of front suspension. Using this procedure, design changes in the suspension components to improve the SOF performance can be done by keeping the suspension durability and other performance requirements as intact.
2017-01-10
Technical Paper
2017-26-0362
Arun Kumar Prasad, Babasaheb Shinde, V A Gopalakrishn
Abstract Hydraulic Load sensing brake valves are used in vehicles from a long time in the market. They proportionate the rear brake line pressure according to the rear axle load in order to avoid the rear wheel lock during braking. During the actual test of the Hydraulic load sensing valve on a subject vehicle, there was drop in performance against its expected peak brake performance. In the current work a detailed analysis is made to understand the sensitivity of the load sensing valve & its effect on the vehicle performance. The parameters affecting the valve sensitivity along with vehicle level factors affecting the performance are analysed during the work.
2017-01-10
Technical Paper
2017-26-0367
Prasad S. Warwandkar, Ashutosh Dubey, Sonu Paroche
Abstract Wheel end bearing is one of the critical components of the vehicle as it directly faces the road loads for harsh operating environment. Bearing being a precisely manufactured component and rotating at high speed, utmost care is required while assembling as well as during operation. In operating condition wheel end is directly exposed to outside environment making it prone to entry of contamination. This contamination if not prevented from entering into wheel end through proper sealing it would cause lubricant contamination and consequently bearing failure. Bearing replacement and overall wheel end service is time consuming activity reducing the turn out time of the vehicle. In wheel ends, one side is sealed with the help of seal while the other side is protected by cap and gasket. This cap-gasket interface is very critical from sealing perspective and utmost importance needs to be taken while designing the same.
2017-01-10
Technical Paper
2017-26-0369
R Muthuraj, Sundararajan Thiyagarajan, E Vignesh, C Kannan, Deepa Praphu
Abstract Overheating in commercial vehicles, even though if it’s in LCV segment, is a problem of high significance. There could be various level of problems that may arise due to heat generation resulting from braking (oversized brake drums left the wheels with lesser packaging clearances for air flow and cooling) and some of them are: 1. Early tire wear /reduction in tire life, 2. Air valve heat damage /air leak issues, 3. Frequent puncture problems, 4. Failure of other mating components and other heat initiated failures. However optimum the vent hole shape in a wheel may be, the air flow in the vicinity of drum periphery and wheel rim ID wouldn’t be sufficient enough because of the lesser clearance and packaging space as mentioned earlier. The basic construction of a wheel with disc welded to rim base ID was apparently modified to integrate the disc and gutter and weld it to rim OD.
2017-01-10
Technical Paper
2017-26-0339
Jagankumar Mari, Egalaivan Srinivasan
Abstract In heavy commercial vehicle segment in India, driver comfort and feel was largely ignored. Fierce competition in the recent years and buyer’s market trend is compelling the designers of heavy truck to focus more on the finer aspects of attribute refinements. Steering is one driver-Vehicle interface which the driver is engaged throughout. Comfort and feel in steering wheel is defined by parameters like steering effort, manoeuvrability, on-center feel & response, cornering feel & response, Torque dead band, return-ability etc. and is influenced by a long list of components and systems in the truck. This study focuses on the influences of jacking torque and steering system friction on the on-center driving performance. Experiments to measure the Jacking torque and steering system friction were conducted in the lab and subjective and objective assessments of on-center driving performance were later conducted at test track in two similar 12 Ton truck to correlate their effects.
2017-01-10
Technical Paper
2017-26-0340
Sarang Bire, Prashant R Pawar, M Saraf
Abstract Air suspension systems had been introduced in automobiles since 1950s. These systems are being explored to improve the ride comfort, handling stability and also serve as a medium for better cargo protection. These system are well developed for buses and high end passenger sedans, also have feasibility for adapting for wide range of configurations of suspension system and axle. Passenger cars and Sports Utility Vehicle (SUV) pickup category of vehicle offers different challenges such as space availability, spring selection and characterization that need to be addressed for successful implementation of air suspension in these category vehicles. This work defines methodology to implement air suspension system in SUV Pickup category vehicle. Paper work includes concept study, mathematical co-relation, and prediction of air spring characteristics and integration of experimental and analytical tool for development of air suspension system.
2017-01-10
Technical Paper
2017-26-0342
Apoorva Radhakrishnan, Hem Rampal, Krishna Kumar Ramarathnam
Abstract Vehicle dynamic simulations demand tire models, which are computationally efficient and capable of reliably predicting the dynamics of the tire. Such simple steady state and transient reduced order models are also required by tire designers to make preliminary predictions concerning behavior and judge quantitatively the relative importance of each of the subcomponents. In the realm of three dimensional multi-body dynamics, most models used are semi-empirical, where the tire is characterized by a set of equations. While the highest hierarchy in the modeling regime is a full three dimensional finite element model, the ensuing deformable multi-body dynamics is not economical for simulation. In this paper we offer an exact methodology to extract tire physical properties in order to develop a reduced order model equivalent to a complete Finite Element tire.
2017-01-10
Technical Paper
2017-26-0344
Kartheek Nedunuri, Vivekanand Patnaik, Santosh Lalasure, K. Rajakumar, Rajiv Modi
Abstract A 4 wheeled vehicle with X-split brake configuration, in hydraulic circuit failed condition will have a behavior of induced sway due to braking force variation in the front and rear diagonally. With increasing vehicle speed, engine power & customer expectations, the situation becomes more critical and challenging in designing a brake system which caters in meeting the homologation requirement at an expense of vehicle sway within controllable limits of driver / customer. This paper proposes a novel approach & methodology to overcome the above situation by predicting the effect of brake force distribution variation on the vehicle swaying behavior during circuit failed braking condition. This study will quantify vehicle sway, caused due to imbalance in brake force distribution during a circuit failed braking event on X Split configuration vehicles.
2017-01-10
Technical Paper
2017-26-0345
Bharat Kushwaha, Sanjay Chaudhuri, Sujatha Chandramohan
Abstract This paper investigates the yaw dynamic behaviour of a seven axle tractor semitrailer combination vehicle developed by VRDE (Vehicle Research & Development). The semitrailer has four steerable axles which follow command steering law i.e. all axles of semitrailer are steered in a particular relation with articulation of tractor. A 4 dof (degree of freedom) linear yaw plane model was developed for this combination vehicle. Yaw response characteristics such as lateral acceleration, yaw rate and articulation angle for step and sine steer is obtained from this model. Effects of speed on the above parameters are also studied to the same steering inputs. Lateral tyre forces due to semitrailer steering at various speeds are estimated to understand its distribution on each axle. Steady state yaw rate and articulation angle gain are obtained to predict the understeer / oversteer behaviour of combination vehicle.
2017-01-10
Technical Paper
2017-26-0194
Ramkumar Rajamanickam, Shriniwas Chivate, Gaurav Shinde, Nagesh Voderahobli Karanth, Shalil Akre, Kishor Desale
Abstract Sound Quality (SQ) of brake and clutch pedal assembly plays an important role in contributing to vehicle interior noise and perception of sound. Quiet operation of brake and clutch units also reflects the vehicle built and material quality. Noise emitted from these sub-assemblies has to meet certain acceptance criteria as per different OEM requirements. Not much work has been carried on this over the years to characterize and quantify the same. An attempt has been made in this paper to study the sound quality of brake and clutch pedal assemblies at component level and validate the same by identifying the parameters affecting SQ. Effect on noise at different environmental conditions was studied with typical operating cycles in a hemi-anechoic chamber. The effect of sensor switches integrated within the clutch and brake pedal on sound quality is analyzed. It is found that the operating characteristics of switches drives the noise and SQ.
2017-01-10
Technical Paper
2017-26-0341
Chaitanya Ashok Vichare, Sivakumar Palanivelu
Abstract The fuel economy of heavy commercial vehicles can be significantly improved by reducing the rolling resistance of tires. To reduce the rolling resistance of 6×4 tractor, the super single tires instead of rear dual wheel tires are tried. Though the field trials showed a significant increase in fuel economy by using super single tires, it posed a concern of road safety when these tires blowout during operation. Physical testing of tire blowout on vehicle is very unsafe, time consuming and expensive. Hence, a full vehicle simulation of super single tire blowout is carried out. The mechanical properties of tires such as cornering stiffness, radial stiffness and rolling resistance changes during the tire blowout; this change is incorporated in simulation using series of events that apply different gains to these mechanical properties.
2017-01-06
Article
Active flow control devices based on electric plasmas can smooth the turbulent wakes that sweep off the rear edges of truck trailers travelling at highway speeds.
CURRENT
2017-01-05
Standard
J1626/2_201701
This Recommended Practice provides a road test procedure for trucks and buses, to evaluate their compliance with Federal Motor Vehicle Safety Standard (FMVSS) 121; Air Brake Systems. Units of measure are English in lieu of metric to be consistent with FMVSS 121.
2016-12-17
WIP Standard
J2394
This SAE standard establishes the minimum construction and performance requirements for seven conductor 1/8 2/10 4/12 cable for use on trucks, trailers and converter dollies. Where appropriate, the standard refers to two types of cables, (Type F and S, described later in the standard), due to the variation in the performance demands of cables used in flexing and stationary applications. While the document’s title refers to ABS Power to differentiate the document from the SAE J1067 standard that it supersedes, the scope applies to both the primary green cable for powering ABS and lighting and the yellow auxiliary cable of the same construction.
CURRENT
2016-12-09
Standard
J1790_201612
The SAE Standard applies to self-propelled, driver-operated sweepers and scrubbers as defined in SAE J2130-1 and SAE J2130-2.
2016-11-30
WIP Standard
J1706
This SAE Recommended Practice is intended to provide basic recommended practices for aid in the development and use of safe and efficient practices for all operations involving the production, handling, and dispensing of SAE J1703 Motor Vehicle Brake Fluids and SAE J1704 Borate Ester Based Brake Fluids.
CURRENT
2016-11-21
Standard
J1102_201611
This SAE Standard covers the chemical, metallurgical and mechanical requirements for two types of passenger car and truck wheel bolts, as follows: (a) Nonserrated shank bolts which are heat treated and (b) Serrated shank bolts which are case hardened.
2016-11-18
WIP Standard
AIRA5C1116
This is a blank form that customers can download in order to record pertinent data after a tire incident using a standardized method.
CURRENT
2016-11-18
Standard
J2828_201611
This SAE Informational report applies to tires used on off-road, rubber-tired work machines as identified in SAE J1116. This SAE document provides general guidelines for proper handling of potential and actual off-road tire fires and possible related explosions.
CURRENT
2016-11-18
Standard
J1102M_201611
This SAE Standard covers the chemical, metallurgical, and mechanical requirements for two types of passenger car and truck wheel bolts, as follows: a. Nonserrated shank bolts which are heat treated b. Serrated shank bolts which are case hardened
2016-11-16
Article
BWI is developing what it believes will be a cost-effective system that would improve ride quality at lower cost than employing magneto-rheological (MR) suspension units.
2016-11-16
Magazine
Focus on advanced safety systems and human-factor interventions The impact of REACH on the aviation sector Considered the most comprehensive chemical-regulation legislation to date, REACH presents serious ramifications for the aircraft industry. Lightweighting: What's Next? Experts weigh in on the challenges and future enablers in the battle to reduce vehicle mass. The best of COMVEC 2016 Autonomous vehicles and improved fuel efficiency via advanced powertrain solutions are pressing topics detailed in this select group of technical papers from the SAE Commercial Vehicle Engineering Congress. Optimizing waste heat recovery for long-haul trucks Autonomous solutions in agriculture Downsizing a HD diesel engine for off-highway applications Zero-emissions electric aircraft: Theory vs. reality
2016-11-16
WIP Standard
J2707
This SAE Recommended Practice specifies a dynamometer test procedure to be used for the measurement of automotive service brake linings and disc brake pads wear. Special motor vehicles and motorcycles are excluded from the application. Trailers with nominal Gross Combination Weight Rating exceeding 40 tons are also excluded from this Recommended Practice.
2016-11-15
Article
Hyliion's electric-drive system hybridizes the trailer portion of the tractor-trailer combination and uses regenerative braking to capture power, possibly saving the trucking industry billions in fuel costs. The company recently won the grand prize in the 2016 "Create the Future" Design Contest for the technology.
CURRENT
2016-11-10
Standard
J2318_201611
This procedure provides test performance requirements for service, spring applied parking, and double diaphragm combination air brake actuators with respect to durability, function, and environmental performance when tested in accordance to SAE J1469.
2016-11-08
Technical Paper
2016-32-0025
Govardan Daggupati, Bapanna Dora Karedla, Chandan Bansilal Chavan, Gagandeep Singh Risam
Abstract In two wheelers the front suspension system is mounted on chassis by two steering bearings which are lubricated ball type angular contact bearings with significant radial force components. These bearings are designed to withstand maximum vehicle loads for target durability. Maximum load carrying capacity depends on the number and size of the balls, bearing size and material. For target durability with designed load carrying capacity, the ball contact pressure, bearing preload plays a major role as compared to other design parameters. Geometry parameters and maximum load defines contact pressure for given bearing design. But in two wheelers due to nature of usage and road conditions, the peak loads are dynamic and geometry based design calculations may not yield the most optimal bearing design. In this work the bearing ball race profile design is optimized by using dynamic bearing contact profiles by using nonlinear Finite Element Analysis.
2016-11-08
Technical Paper
2016-32-0054
Barath Mohan, KVM Raju, Sai Praveen Velagapudi, Chandramouli Padmanabhan
The aim of the present study is to develop feasible test methods to measure the lateral force characteristics of motorcycle tires. In this work, new experimental procedures are developed to estimate the lateral friction coefficient and lateral stiffness characteristics of motorcycle tires. A fairly accurate tire model is developed using the measured lateral force characteristics. Based on this tire model, the steer behavior and the cornering limits of the motorcycle are estimated using an analytical model of the vehicle. The results are validated with experimental data. The test methods proposed are shown to be adequate to estimate tire characteristics that are important for tire development and is less expensive compared to the standard testing facilities available.
2016-11-08
Technical Paper
2016-32-0053
Hisato Tokunaga, Kazuhiro Ichikawa, Takumi Kawasaki, Akiyuki Yamasaki, Tatsuo Ichige, Tomoyuki Ishimori, Yoichi Sansho
Abstract Owing to the recent developments in sensors with reduced size and weight, it is now possible to install sensors on a body of a motorcycle to monitor its behavior during running. The analysis of maneuverability and stability has been performed based on the data resulted from measurements by these sensors. The tire forces and moments is an important measurement item in maneuverability and stability studies. However, the tire forces and moments is difficult to measure directly, therefore, it is a common practice to measure the force and the moment acting on the center of the wheel. The measuring device is called a wheel forces and moments sensor, and it is widely used for cars. The development of a wheel forces and moments sensor for motorcycles has difficulty particular to motorcycles. First, motorcycles run with their bodies largely banked, which restricts positioning the sensors.
2016-11-08
Journal Article
2016-32-0051
Keisuke Terada, Takayuki Sano, Kenichi Watanabe, Takashi Kaieda, Kazuhisa Takano
Abstract In recent years three-wheel camber vehicles, with two wheels in the front and a single rear wheel, have been growing in popularity. We call this kind of vehicle A “Leaning Multi Wheel category Vehicle” (hereinafter referred to as a “LMWV”). A LMWV has various characteristics, but one of them stands out in particular. When a LMWV is cornering, if one of the front wheels passes over a section of road surface with a low friction coefficient, there is very little disturbance to the vehicle’s behavior and can continue to be driven as normal. However, there has been no investigation into why these vehicles have this particular characteristic. Consequently, in this paper an investigation was carried out in order to determine the behavior of a LMWV in this situation. First, measurements were taken using an actual vehicle to confirm the situation described above.
Viewing 121 to 150 of 10887

Filter