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Viewing 211 to 240 of 8249
2017-01-10
Technical Paper
2017-26-0313
Manoj Kumar Rajendran, Srinivasa Chandra V, Manikandan Rajaraman, Dinesh Kumar Rajappan, Agathaman Selvaraj
Abstract In today competitive world, gaining customer delight is the most vital part of an automotive business. Customers’ expectations are high which need to be satisfied limitless, to stay in the business. The major expectation of a commercial vehicle customer is a vehicle without failures which involves lower spares cost and downtime. The significance of a suspension system in the new age automobiles is getting advanced. There have been many improvements in the suspension system especially in leaf springs to provide a better ride comfort, and one such modern era implementation is the Parabolic Spring which comprises of fewer leaves with varying thickness from the center to the ends without inter-leaf friction. Study reveals that parabolic spring exhibits better ride comfort, but less life compared to a conventional leaf spring which leads to the increase in downtime of the vehicle.
2017-01-10
Technical Paper
2017-26-0315
Jyoti Kale, Satish Kumar, Pravin Lavangare, Anand Subramaniam
Abstract The Steering system is one of the most safety critical systems in an automobile. With time the durability, reliability and the fine-tuning of the parameters involved in this subsystem have increased along with the competitiveness of the market. In a competitive market, accelerated testing is the key to shorter development cycles. It is observed that the majority of component manufacturers have a preference on vehicle level testing to achieve their development goals. The vehicle level trials are time consuming and lack the control and repeat-ability of a laboratory environment. This paper describes the development of a steering test rig designed to simulate the disturbances experienced on road within a controlled laboratory environment. The five axis steering rig would allow simulation of individual road wheel displacement along with steering wheel angle input and lateral steering rack displacements. The rig also is designed to be adaptable to a range of vehicle categories.
2017-01-10
Technical Paper
2017-26-0310
Vyankatesh Madane, Sameer Shivalkar, Chandrakant Patil, Sanjeev Annigeri
Abstract In rubber industry, different techniques are used to enhance durability. This paper gives complete design, development and testing methodology of rubber bush in which pre-compression of rubber is used to enhance rubber bush life. In bogie suspension, axle to torque rod join is critical as it has to transfer lateral and longitudinal load with flexibility. This makes challenging to design joint which need to carry more than 6 ton load and having flexibility of more than 10 degree articulation. In this torque rod to axle joint called as End bush, compressed rubber is used to carry high load with flexibility. Other possible material for bush can be brass bush which able to carry high load however not able to give high flexibility Design and finite element calculations are done to design pre-compression and rubber volume to get desired strength and stiffness to carry required load with flexibility.
2017-01-10
Technical Paper
2017-26-0312
Sagar Polisetti, Ganeshan Reddy
Abstract Twist beam is a type of suspension system that is based on an H or C shaped member typically used as a rear suspension system in small and medium sized cars. The front of the H member is connected to the body through rubber bushings and the rear portion carries the stub axle assembly. Suspension systems are usually subjected to multi-axial loads in service viz. vertical, longitudinal and lateral in the descending order of magnitude. Lab tests primarily include the roll durability of the twist beam wherein both the trailing arms are in out of phase and a lateral load test. Other tests involve testing the twist beam at the vehicle level either in multi-channel road simulators or driving the vehicle on the test tracks. This is highly time consuming and requires a full vehicle and longer product development time. Limited information is available in the fatigue life comparison of multi-axial loading vs pure roll or lateral load tests.
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
2017-26-0344
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
2017-26-0342
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
2017-26-0341
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.
2017-01-10
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
2017-26-0363
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
2017-26-0194
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
2017-26-0217
Arvind Kumar Yadav, Mayur Birari, Vilas Bijwe, Dayanand Billade
Abstract Crank train torsional vibration is an important aspect for design and development of Powertrain for NVH refinement and durability. Crank train torsional vibration parameters like angular acceleration of flywheel or twist, depends upon various design parameters like geometry of crankshaft, mass of flywheel, stiffness of clutch, mass of pulley etc. It also depends upon engine operating conditions like engine speed, engine load, combustion peak pressure and combustion pressure variation etc. Most of these parameters are decided by engine power, torque, engine architecture and packaging constraints. Addition of torsional vibration damper (TVD), which works on the principle of tuned dynamic absorber, is commonly deployed design solution to control the torsional vibrations as well as stresses (to improve durability of crank train) induced in crank train assembly at specified modal frequency.
2017-01-10
Technical Paper
2017-26-0220
Ashutosh Dubey, Palish Raja, Nitin Chopra, Ashok Patidar, Manu Kaushik
Abstract With the increase in the sensitivity of power steering system in the competitive environment, it becomes essential to provide a trouble free steering system to the customer. Usually major concerns faced in the performance of steering system are related to noise like vane pump whining noise and steering gearbox erratic rubbing noise. Even though selected steering pump and reservoir are quite compatible to the steering gearbox. With the series of Computational Fluid Dynamics (CFD) simulations and field tests, it is found that the cavitation phenomena in steering oil routing lines is responsible for the steering turning noise. In this paper, a developed systematic approach for problem detection to implementation of design solution is discussed.
2017-01-10
Technical Paper
2017-26-0246
Srinivas Kurna, Ruchik Tank
Abstract The job of a suspension system is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to act as a cushioning device to ensure the comfort of the driver and passengers. The suspension system also protects the vehicle and any cargo or luggage from damage and wear. Commonly the strength of these suspension systems is evaluated by endurance trials on field or Rig testing which are time consuming and costly. On the other hand, virtual testing methods for strength and stiffness evaluation provide useful information early in the design cycle and save significant time and cost. However, the virtual method also needs validation, which can be achieved by physical co-relations (via rig tests). A study has been done to predict the behavior of Leaf Spring Suspensions entirely through the FEA (Finite Element Analysis) route and correlating those results with physical test.
2017-01-10
Technical Paper
2017-26-0080
P. Ramani Ranjan Senapati, Soumyo Das, Prashantkumar B. Vora
Abstract The development of intelligent driver assistance mechanism ensures safety and comfort of passengers, the intelligent braking and maneuvering mechanism is proposed by transforming the anti-lock braking technology for a four wheeled vehicle. This paper presents an active safety mechanism which incorporates both steering and braking assistance system in a maneuvering vehicle. The algorithm of collision avoidance mechanism is featured and interfaced in an intelligent vehicle with short range radar to assist driving system of host vehicle based on predicted motion of sensed obstacles. The developed system will be activated for obstacles in front of the host vehicle within critical risk level. The intelligent braking mechanism plays a pivotal role at the time of emergency situation depending on the predicted collision time and relative velocity between host and target, it also provides assistance to avoid panic situation for driver.
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
2017-26-0292
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
2017-26-0218
Chaitanya Chilbule, S B Phadke, R N Kulkarni, M P Raajha
Abstract As an automobile brake manufacturer, brake noise always been a prime concern as it define the degree of customer satisfaction and warranty claim. Brake squeal is a concern in the automotive industry that has challenged many researchers and engineers for years. In case of disc brake, brake-squeal (1 to 16 kHz) occurrence is predominant than the any other types of brake-noise (i.e. moan, grown, judder etc.), since squeal is a friction induced, self-excited, and self-sustained phenomenon from a nonlinear dynamics viewpoint. Due to the complexities involve squeal mechanism is not well understood yet, hence makes it one of the unresolved brake Noise, Vibration, and Harshness (NVH) problem till this date. Since squeal is a high-pitched and tonal noise, therefore it is very annoying and getting more attention by occupants. Brake squeal can occur at any temperature and with or without the presence of humid condition and therefore highly unpredictable.
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
2016-32-0053
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.
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.
2016-10-25
Technical Paper
2016-36-0348
André de Moura Oliveira, Elvis Bertoti, Jony Javorski Eckert, Rodrigo Yassuda Yamashita, Eduardo dos Santos Costa, Ludmila Corrêa de Alkmin e Silva, Franco Giuseppe Dedini
Abstract The need for improved fuel economy for road vehicles has increased the interest in hybrid electric vehicle (HEV) and recovering vehicle energy. This paper aims to evaluate the amount of kinetic energy that could be restored through regenerative braking in a HEV. This work will not resort the Brazilian urban driving cycle NBR 6601, for this cycle does not fully represent a pattern of traffic faced regularly in urban areas, which is typically composed of heavy traffic and long periods of idleness. Therefore, a new drive cycle will be developed that better represents the Brazilian traffic. Also, considering the shortage of energy resources, the large amount of energy dissipated as heat during braking a vehicle is a recurring concern. Therefore, measuring the maximum available energy that could be restored through regenerative braking is the first step towards estimating the profit of using this technology and how it would pay off the investment in the long run.
2016-10-25
Technical Paper
2016-36-0239
Lucas Iensen Bortoluzzi, Adriano Schommer, Mario Martins, Alexandre Aparecido Buenos
Abstract In many vehicle motorsport categories, the one of the most important factors that lead a team to the victory is the suspension setup. Parameters like roll stiffness and camber changing are essential to the vehicle behavior during a driving situation. To handle these variables, features like suspension hardpoints arrangement, pivot points position and spring stiffness can be settled. However a setup only will perform a desirable effect if the chosen configuration does not change. Ideally, to make it possible, every component that holds suspension loads (suspension members, mounting plates and chassis) would have to be infinitely rigid. Even though it is not achievable, the existing deformation can be small enough to be negligible when compared with suspension displacement. In order to reach this target, this paper introduce a spring modeling and a Finite Element multibody modeling process of a Formula SAE prototype’s suspension and chassis.
2016-10-25
Technical Paper
2016-36-0242
A. C. R. Ramos, R. B. Santos, C. A. P. Melo, I. C.S. Perez
Abstract Noise, vibration and Harshness in the automotive industry became important mainly because the development of modern automobiles and the increased of customer demands for quieter vehicles and with comfortable vibration levels. The sources of vibration and noise inside the vehicle are caused by the engine, tires, transmission systems, suspension, air conditioning, among others. In this work, vibroacoustic transfer function is obtained to analyze the internal noise in two sport utility vehicle with distinctive silhouette. Furthermore, it was analyzed the influence of elastomeric bushings rigidity of the damper in reducing internal noise and vibration and the effect of adding mass in some framework positions for attenuation of vibration peaks due to structural resonance.
2016-10-25
Technical Paper
2016-36-0140
Rodrigo Luiz de Campos
Abstract This work aims to summarize in a single form all legal requirements that dictates the minimum safety compliance required by government edicts to any wheel manufacture to have their products available for passenger or light truck vehicle in any country around the world in the year of 2016. It is not intention of this paper compare or discuss the different requirement among the countries but indicate to the manufactures of wheels what legal edicts they need to meet in case they are willing to go overseas to explore the wheel market of other country. Before start designing wheels for passenger or light truck application, any manufacture should be sure about what the government of the new market demands for wheels when installed on vehicle axis or just available as temporary spare.
2016-10-25
Technical Paper
2016-36-0157
Paulo Augusto Mayer, Anderson Petronilho, André Tognolli, Fabio Santos Batista, Jamilton Vidal da Silva
Abstract The high level of reliability of virtual analysis for suspension system development should not be thinking only for comfort and performance purpose, considering the `growing number of failures due to the touch between components in dynamic condition. The study establishes a simple and optimized methodology, able to predict more accurately the flexible brake hose path subject to the steering motion and associates with the independent suspension course, aiming the best route in order to achieve a low cost and robust design. In turn, the flexible brake hose non-linear model invalidates the multibody study to get the best route. However, with the aid of motion making use of NX9 [1] CAD [2] software was prepared dynamic movement that subjects front independent suspension system that establishes a Cartesian routine that maps 977 points, much higher than 9 points from previous studies, comprising a more accurate path performed by the hose.
Viewing 211 to 240 of 8249