Browse Topic: Tire friction

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A novel approach for Combi Braking System design considering tire's nonlinear behavior2024-26-005801/16/2024
The standard usage of Combined Braking System (CBS) in lower cc/power 2-wheeler vehicles serves to reduce stopping distance and improve braking stability. The CBS system achieves this by engaging both the front and rear wheel brakes, taking advantage of the high load transfer characteristic during 2-wheeler braking. However, the current design of the CBS system relies on linear system analysis, based on vehicle geometry, load distribution, and tire-road friction. This approach overlooks the non-linearities inherent in braking dynamics, such as tire behavior and dynamic Center of Gravity (CoG) location. Consequently, the current CBS design methodology exhibits limitations, particularly in extreme scenarios where wheel lock-up may occur, such as on low friction surfaces or during panic braking. This paper proposes the incorporation of tire non-linearities into the design of CBS systems using Pacejka's tire model. Initially, calculations are performed to optimize the braking
Khandekar, Piyush, Badiger, Kartik, Gautam, Ashish, Soni, Lokesh
Topological Optimization of Non-Pneumatic Unique Puncture-Proof Tire System Spoke Design for Tire Performance15-17-01-000107/18/2023
Abstract Non-pneumatic tires (NPTs) have been widely used due to their advantages of no occurrence of puncture-related problems, no need of air maintenance, low rolling resistance, and improvement of passenger comfort due to its better shock absorption. It has a variety of applications as in earthmovers, planetary rover, stair-climbing vehicles, and the like. Recently, the unique puncture-proof tire system (UPTIS) NPT has been introduced for passenger vehicles segment. The spoke design of NPT-UPTIS has a significant effect on the overall working performance of tire. Optimized tire performance is a crucial factor for consumers and original equipment manufacturers (OEMs). Hence to optimize the spoke design of NPT-UPTIS spoke, the top and bottom curve of spoke profile have been described in the form of analytical equations. A generative design concept has been introduced to create around 50,000 spoke profiles. Finite element model (FEM) model is developed to evaluate the stiffness and
Dhrangdhariya, Priyankkumar, Maiti, Soumyadipta, Rai, Beena
Topological Optimization of Non-Pneumatic Unique Puncture-Proof Tire System Spoke Design for Tire Performance15-17-01-0001-TEST-REC07/18/2023
Abstract Non-pneumatic tires (NPTs) have been widely used due to their advantages of no occurrence of puncture-related problems, no need of air maintenance, low rolling resistance, and improvement of passenger comfort due to its better shock absorption. It has a variety of applications as in earthmovers, planetary rover, stair-climbing vehicles, and the like. Recently, the unique puncture-proof tire system (UPTIS) NPT has been introduced for passenger vehicles segment. The spoke design of NPT-UPTIS has a significant effect on the overall working performance of tire. Optimized tire performance is a crucial factor for consumers and original equipment manufacturers (OEMs). Hence to optimize the spoke design of NPT-UPTIS spoke, the top and bottom curve of spoke profile have been described in the form of analytical equations. A generative design concept has been introduced to create around 50,000 spoke profiles. Finite element model (FEM) model is developed to evaluate the stiffness and
Dhrangdhariya, Priyankkumar, Maiti, Soumyadipta, Rai, Beena
Design Optimization of Bicycle Wheel Hub Assembly for Automotive Applications2022-01-030503/29/2022
The diminutive rolling resistance and wheel bearing drag characteristics of a bicycle wheel assembly makes it a lucrative choice of component in numerous 3-wheeled (3W) and 4-wheeled (4W) automotive applications. However, when a bicycle wheel is subjected to the loads encountered in such applications, complications pertaining to strength, durability and, performance are encountered. Since a bicycle wheel is intended to be arrested at either end of its axle, cantilever loading of the component as practiced in automotive applications diminishes the ability of the spindle to withstand longitudinal, and vertical forces encountered. Furthermore, while cornering on a bicycle, the maneuver of leaning in a corner significantly reduces the lateral stiffness requirement of the hub flanges. Therefore generic hub assemblies are designed without accounting for the action of lateral forces that are experienced at the hub with the wheel held vertical. Since most bicycle wheel assemblies are designed
Chakraborty, Apurva, R, Shreyas, Kanhai, Palash
Medium- and heavy-duty value of technology improvement 2022-01-064303/29/2022
Improvements in vehicle technology have an impact on the purchase price of the vehicle and its operating cost. In this study, we assume the monetary benefit of a technology improvement includes the potential reduction in vehicle price from using cheaper or smaller components, as well as the discounted value of the fuel cost savings. As technology progresses over time, the value and benefit of improving technology varies as well. For example, when a battery is heavy and expensive, a percentage increase in energy density and percentage reduction in cost are worth more than when the battery is already lighter and cheaper. In this study, we look at the value of a few technologies (battery energy density, electric drive efficiency, tire rolling resistance, aerodynamics, light weighting) and assign a dollar value to its associated savings. We show how the dollar value changes with the level of technology achievement, the powertrain selection and the vehicle type. We highlight for instance
Freyermuth, Vincent, Vijayagopal, Ram, Rousseau, Aymeric
Influence of Tyre Rolling Resistance and Operational Parameters on Vehicle Fuel Efficiency2021-26-050309/22/2021
There has been a persistent demand for Vehicle fuel efficiency improvement, mainly due to ever-increasing fuel price and imposition of stricter regulatory norms to curb greenhouse gas emissions. Factors like driving style, vehicle weight, engine, tyre, aerodynamics, weather conditions, etc. affect fuel efficiency. This study focuses on the impact of certain sub-parameters like tyre construction, tyre wear, inflation pressure and driver behavior to establish a correlation between the Rolling Resistance Coefficient (RRC) of a tyre and the fuel efficiency of the vehicle. Tyres with contrasting RRC are considered with multiple drivers and driving conditions while measuring Fuel efficiency using test cycles defined as Constant Speed Test (CST), Mixed Cycle Test (MCT) and Public Road Test (PRT). Fuel consumption sensitivity to driving behavior or driving aggressiveness varies even within expert drivers [1][2]. Reduction in Non-Skid Depth due to tyre wear adversely affects its properties
TOMER, AVINASH, Chepyala, Shiva Kumar Reddy, Mukhopadhyay, Rabindra, Ghosh, Prasenjit
Coastdown Road Load Coefficients of Passenger Vehicles – Variation Analysis and its Correlation with Temperature2021-26-048709/22/2021
Road Load parameters (rolling resistance & aerodynamic drag) of a vehicle have strong impact on overall Vehicle Emissions & Fuel Economy. The road load coefficients are simulated on chassis dynamometer to carryout emission & fuel economy measurement and are hence required to be found beforehand. A realistic measure of road load parameters can be obtained by conducting a coastdown test. Coastdown test results are hugely impacted by various environmental parameters like ambient temperature, atmospheric pressure, wind speed etc. Though performed in standard boundary conditions, results of multiple tests performed on a vehicle vary from one another due to variations in the mentioned environmental parameters over & above standard test to test variation. This paper aims at studying the variation in test results due to ambient temperature as one of the parameters responsible. For this study, road load coefficients from more than 100 coastdown tests conducted on oval test track for almost 30
Kuhar, Saurabhh, Pattalwar, Ashutosh, Gupta, Parveen
The Effect of Using the Same Tire Friction for Both Vehicles in Impact Speed Reconstructions2021-01-089904/06/2021
Most collision reconstructions implicitly assume the same tire/road friction coefficient for all vehicles, despite evidence that friction varies between tires, surfaces, and individual trials. Here we assess the errors introduced by an assumption of a single, universal friction coefficient when reconstructing a collision where vehicles actually had different tire frictions. We used Monte Carlo methods to generate 20,000 synthetic two-vehicle impacts and rest positions using different, randomized friction coefficients for each vehicle and randomized impact speeds. These rest positions were then used to reconstruct both vehicles’ impact speeds assuming a single, common friction coefficient. High and low bounds on the impact speeds were reconstructed using high and low bounds on the common friction. We found that more than 97% of the true impact speeds were in the ranges reconstructed using upper and lower friction bounds. The influence of the similar-friction assumption on the errors in
Heinrichs, Bradley E., Toscano, Dwayne
Speed Planning System for Commercial Vehicles in Mountainous Areas2021-01-0126-TEST-REC04/06/2021
There are a large number of curves and slopes in the mountainous areas. Unreasonable acceleration and deceleration in these areas will increase the burden of the brake system and the fuel consumption of the vehicle. The main purpose of this paper is to introduce a speed planning and promotion system for commercial vehicles in mountainous areas. The wind, slope, curve, engine brake, and rolling resistances are analyzed to establish the thermal model of the brake system. Based on the thermal model, the safe speed of the brake system is acquired. The maximum safe speed on the turning section is generated by the vehicle dynamic model. And the economic speed is calculated according to the fuel consumption model. The planning speed is provided based on these models. This system can guide the driver to handle the vehicle speed more reasonably. According to the simulation, compared to cruise control, speed planning can save fuel consumption at a mean value of 9.13% in typical mountainous areas
Peng, Dengzhi, Fang, Kekui, Tian, Zhongpeng, Zhang, Yuxiao, Tan, Gangfeng
Speed Planning System for Commercial Vehicles in Mountainous Areas2021-01-012604/06/2021
There are a large number of curves and slopes in the mountainous areas. Unreasonable acceleration and deceleration in these areas will increase the burden of the brake system and the fuel consumption of the vehicle. The main purpose of this paper is to introduce a speed planning and promotion system for commercial vehicles in mountainous areas. The wind, slope, curve, engine brake, and rolling resistances are analyzed to establish the thermal model of the brake system. Based on the thermal model, the safe speed of the brake system is acquired. The maximum safe speed on the turning section is generated by the vehicle dynamic model. And the economic speed is calculated according to the fuel consumption model. The planning speed is provided based on these models. This system can guide the driver to handle the vehicle speed more reasonably. According to the simulation, compared to cruise control, speed planning can save fuel consumption at a mean value of 9.13% in typical mountainous areas
Peng, Dengzhi, Fang, Kekui, Tian, Zhongpeng, Zhang, Yuxiao, Tan, Gangfeng
Dynamic Cleat Test with Perpendicular and Inclined CleatsJ2730_202101 (Current)01/13/2021
This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a high frequency response spindle when a rolling tire impacts a cleat. The cleat is configured either with its crest perpendicular, 90 degrees, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides impact force and moment time histories essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development.
Vehicle Dynamics Standards Committee
Dynamic Cleat Test with Perpendicular and Inclined CleatsJ2730_202101-TEST-REC (Historical)01/13/2021
This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a high frequency response spindle when a rolling tire impacts a cleat. The cleat is configured either with its crest perpendicular, 90 degrees, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides impact force and moment time histories essentially free from variations due to tire non-uniformities. The method applies to any size tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development.
Vehicle Dynamics Standards Committee
Rolling Resistance Measurement Procedure for Passenger Car, Light Truck, and Highway Truck and Bus TiresJ1269_202012 (Current)12/22/2020
This SAE Recommended Practice applies to the laboratory measurement of rolling resistance of pneumatic passenger car, light truck, and highway truck and bus tires. The procedure applies only to the steady-state operation of free-rolling tires at zero slip and inclination angles; it includes the following three basic methods:
Highway Tire Committee
Rolling Resistance Measurement Procedure for Passenger Car, Light Truck, and Highway Truck and Bus TiresJ1269_202012-TEST-REC (Historical)12/22/2020
This SAE Recommended Practice applies to the laboratory measurement of rolling resistance of pneumatic passenger car, light truck, and highway truck and bus tires. The procedure applies only to the steady-state operation of free-rolling tires at zero slip and inclination angles; it includes the following three basic methods:
Highway Tire Committee
STANDARD FOR TIRE TRACEABILITY CONTENT AND FORMAT FOR THE RADIO-FREQUENCY IDENTIFICATION (RFID) TAG AND ASSOCIATED TIRE DATA SETUSCAR39-1 (Current)11/19/2020
This standard describes a requirement for automotive tire traceability. It includes a definition of the RFID tag and the associated tire data set that can be accessed using the RFID tag as an identifier. The standard describes a unique identification and the associated data set for each tire produced by the tire fabricator. This data will either be provided or transmitted at the time of shipment to retailers, wholesalers or original equipment vehicle manufacturers. Tire identification code and data may be used for error proofing, determining the tire specifications or supporting any inquiries that occur for the duration of its automotive life.
USCAR
Rolling Resistance Measurement Procedure for Highway Truck and Bus TiresJ1379_202011 (Current)11/12/2020
This recommended practice applies to the laboratory measurement of the rolling resistance of pneumatic tires designed primarily for use on trucks and buses in normal highway service, as defined by the Tire and Rim Association, Inc. (TRA); it does not include light truck tires (designated LT). The procedure applies only to straight, free-rolling tires under steady-state operation and includes the following three basic methods:
Truck and Bus Tire Committee
The Measurement of Highway Truck and Bus Tire Rolling ResistanceJ1380_202011 (Current)11/09/2020
The force, torque, and energy methods of measurement are all in common use and should yield the same test results. Effects of steering, traction, and non steady-state tire operations are excluded from the recommended practice because they are still in the research stage. Methods of correcting laboratory data to road conditions are being developed.
Truck and Bus Tire Committee
Tire pressure's impact on EV driving range20AUTP11_0311/01/2020
A new study shows that tighter control of tire-pressure loss can lead to marked improvement in electric-vehicle efficiency. Electric-vehicle development teams have made great advances in improving vehicle range, mitigating “range anxiety” for the end customer. While much focus has been on advances in battery technology, controls and vehicle aerodynamics, EV driving range also is significantly affected by tires. Energy-inefficient tire construction, sub-optimal inflation and other factors can adversely impact EV range. Tires lose a certain amount of air on a continuous basis. An underinflated tire is less stiff and its deformation is much higher, leading to a larger amount of heat dissipation and ultimately higher rolling resistance and poor range efficiency.
Tang, Lamei, Wei, Sheng, Valentage, Jeffrey, Li, Zheng, Nair, Sujith
Road Load Measurement Using Onboard Anemometry and Coastdown TechniquesJ2263_202005 (Current)05/26/2020
This SAE Recommended Practice establishes a procedure for determination of vehicle road load force for speeds between 115 km/h and 15 km/h (or between 70 mph and 10 mph). It employs the coastdown method and applies to vehicles designed for on-road operation. The final result is a model of road load force (as a function of speed) during operation on a dry, level road under reference conditions of 20 °C (68 °F), 98.21 kPa (29.00 in-Hg), no wind, no precipitation, and the transmission in neutral.
Light Duty Vehicle Performance and Economy Measure Committee
Road Load Measurement Using Onboard Anemometry and Coastdown TechniquesJ2263_202005-TEST-REC (Historical)05/26/2020
This SAE Recommended Practice establishes a procedure for determination of vehicle road load force for speeds between 115 km/h and 15 km/h (or between 70 mph and 10 mph). It employs the coastdown method and applies to vehicles designed for on-road operation. The final result is a model of road load force (as a function of speed) during operation on a dry, level road under reference conditions of 20 °C (68 °F), 98.21 kPa (29.00 in-Hg), no wind, no precipitation, and the transmission in neutral.
Light Duty Vehicle Performance and Economy Measure Committee
Research on Factors to Influence Coasting Resistance for Electric Vehicles2020-01-106804/14/2020
The research on coasting resistance is vital to electric vehicles, since the smaller the coasting resistance, the longer the coast-down distance. Vehicle coast resistance consists of rolling resistance, vehicle inner resistance and the aerodynamic drag. The vehicle inner resistance is mainly caused by driveline’s friction loss and oil splash loss. The rolling resistance is decided by tire resistance coefficient, which is influenced by tires and road conditions. And the aerodynamic drag is affected by vehicle’s shape and air. In this paper, four factors including tire pressure, road surface condition, atmosphere temperature, and recirculation on or off are examined. Experimental tests have been conducted on three different vehicles: one subcompact sedan, one compact sedan and one subcompact SUV. Then experimental results have been imported to simulation model to investigate the corresponding influence on NEDC range. The outcome shows that, when the tire pressure is 20% less, the average
Gong, Guan, Zhao, Chen, Zhou, Xiaohang, Deng, Chenghao, Jiang, Hanli, Yu, Cheng, Yu, Fuyong, Ren, Yong, Zhou, Anjian
A Study on the Effect of Tire Temperature and Rolling Speed on the Vehicle Handling Response2020-01-123504/14/2020
Rubber is a non-linear viscoelastic material which properties depend upon several factors. In a tire two of these factors, namely the temperature and excitation frequency, are significantly influenced by the vehicle operating conditions. In the past years, applied research studied how rubber viscoelastic characteristics affect structural and frictional tire properties. The present study focuses on how these effects interact with the vehicle handling response. Based on state of the art theory of friction, structural properties of rubber and on experimental evidence, the dependency of key tire parameters on temperature and rolling speed is established. These results are then used in combination with a single-track vehicle model to assess their impact on key vehicle parameters; as an example, the understeer coefficient, yaw resonance peak / damping and maximum acceleration are studied. Furthermore, to ensure accurate results in realistic situations, a novel tire thermodynamic model is
Lugaro, Carlo, Alirezaei, Mohsen, Konstantinou, Ioannis, Behera, Abhijeet
Comparative Study on the Effects of the Tread Rubber Compounds on Tire Tractive performance on Ice2020-01-122804/14/2020
Mechanical and thermal properties of the rubber compounds of a tire play an important role in the overall performance of the tire when it is in contact with the train. Although there are many studies conducted on the properties of the rubber compounds of the tire to improve some of the tire characteristics such as the wear of the tread, there is a limited number of studies that focus on the performance of the tires on ice. This study is part of a more comprehensive study to investigate the effect of rubber compounds on performance of the tire on ice. In this study three tires that are completely identical in terms of tire parameters (such as tire dimensions, treat pattern, tire structure, inflation pressure, etc., but have different tread rubber compounds have been investigated. Several tests have been conducted for the chosen tires in three modes: free rolling, braking, and traction using the Terramechanics Rig at TMVS at Virginia Tech. In this presentation we will only focus on the
Mousavi, Hoda, Sandu, Corina
The Effect of Structural Damping Foam on Tire Vibration10-04-02-000602/28/2020
During the vehicle design state, vehicle noise and vibration are taken into consideration. The tire is a large contributor to the noise and vibration experienced inside the vehicle cabin. Any unevenness or asperities in the road cause the tire structure to vibrate, which in turn causes components in the vehicle to vibrate and generate noise. It is common in the industry to use foam inserts inside the tire air cavity that reduces the noise generated. This foam is typically intended to reduce a specific resonance in the tire-the resonance due to the air cavity. Recently, there is interest in using foam as a structural damper to reduce structural resonances in the tire. A new analytical tire model for determining the effect that structural damping foam has on the noise and vibration characteristics of the tire has been developed. The theoretical formulation of this model is presented, as well as comparison with experiments and a parametric analysis of the model. The model shows good
Sams, Thomas
Rolling Resistance Measurement Procedure for Passenger Car, Light Truck, and Highway Truck and Bus TiresJ1269_201912 (Historical)12/10/2019
This SAE Recommended Practice applies to the laboratory measurement of rolling resistance of pneumatic passenger car, light truck, and highway truck and bus tires. The procedure applies only to the steady-state operation of free-rolling tires at zero slip and inclination angles; it includes the following three basic methods:
Highway Tire Committee
Effect of Tyre Inflation Pressure on Rolling Resistance: Comparing the Values of Coefficient of Rolling Resistance and Rolling Resistance at Variable Tyre Inflation Pressure2019-28-241511/21/2019
1.  Rolling resistance, is nothing but the rolling drag, is the force resisting the motion when a body rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation of the wheel, roadbed, etc. It is recovered when the pressure is removed, in the form of hysteresis losses and permanent deformation of the tyre surface. So, the rolling resistance contributes to the deformation of roadbed as well as tyre surface of the vehicle. Factors contributing in rolling resistance are tyre inflation pressure, wheel diameter, speed, load on wheel, surface adhesion, sliding and relative micro-sliding between the surfaces of contact. In this concerned paper we are significantly working on effect of tyre inflation pressure on rolling resistance and taking all other factors constraint.
Tripathi, Siddharth, Karwal, Amit Kumar, Mishra, Mukund, Wazir, Dushyant
Performance Gains of Load Sensing Brake Force Distribution in Motorcycles2019-28-242611/21/2019
Commercial motorcycles and scooters incorporate independent circuits for front and rear brake actuation, thus precluding load-dependent brake force distribution. In all cases of manual brake force modulation between the front and rear wheels, there is poor compensation for the changes in wheel loads on the account of longitudinal weight transfer, thus making it challenging to provide an adequate braking force to each wheel. The ratio in which the braking force should be distributed between the front and the rear wheels is dependent on the motorcycle’s geometry, weight distribution, mechanical sizing of braking system components, and is a variable based on the instantaneous deceleration. This connotes that a fixed bias of front and rear braking forces can be optimized only for a narrow range of motorcycle’s deceleration. Maximum braking performance occurs just prior to wheel lock-up, as a sliding tire provides less grip than a rolling tire. This is also the scenario when both the tires
Chakraborty, Apurva
Continental Tire rolls towards a smart-and-connected future19AUTP10_0910/01/2019
It is difficult to become emotional about tires except when they-literally-let us down. But tires are set to get smarter, communicate more effectively and react to changing road conditions. Each of these will play a role in meeting the demands of autonomous- and electric-vehicle (AV/EV) development. “They will be tires that take care of themselves and provide highly supported driving,” said Dr. Philipp Struck, Continental Tire's head of tire line development. “Mobile data will be essential as we become more autonomous and drive more EVs.”
Birch, Stuart
Stability of Wheel Tractors during Braking2019-01-214209/15/2019
The dynamic distribution of normal reactions between the axles of the wheeled tractor has a significant impact on the stability against skidding and the wheeled tractor braking effectiveness. At the same time, the clarification of the normal reactions distribution between the axles allows to choose more rational braking forces distribution between the axles. It is shown that the best way to ensure the highest braking efficiency is the braking mode when the rear wheels of the tractor are at the blocking limit. An assessment of the expediency of installing brake mechanisms on only one axle of the tractor was made. The increase of braking efficiency of wheeled tractors with all brake wheels provided that they ensure directional stability is considered. The laws of braking forces distribution between the axles of wheel tractors for different sequence of wheels locking are determined. Using the method of partial accelerations an improved method for estimating the effect of a brake system on
Podrigalo, Mikhail, Kholodov, Mykhailo, Klets, Dmytro, Dubinin, Yevhen, Savchenkov, Borys, Koryak, Alexander, Rudzinskyi, Volodymyr, Viktoriia, Zadorozhnia, Polianskyi, Oleksandr
Electrifying Long-Haul Freight—Part I: Review of Drag, Rolling Resistance, and Weight Reduction Potential02-12-03-001709/05/2019
Abstract Electric heavy-duty tractor-trailers (EHDTT) offer an important option to reduce greenhouse gases (GHG) for the transportation sector. However, to increase the range of the EHDTT, this effort investigates critical vehicle design features that demonstrate a gain in overall freight efficiency of the vehicle. Specifically, factors affecting aerodynamics, rolling resistance, and gross vehicle weight are essential to arrive at practical input parameters for a comprehensive numerical model of the EHDTT, developed by the authors in a subsequent paper. For example, drag reduction devices like skirts, deturbulators, vortex generators, covers, and other commercially available apparatuses result in an aggregated coefficient of drag of 0.367. Furthermore, a mixed utilization of single-wide tires and dual tires allows for an optimized trade-off between low rolling resistance tires, traction, and durability. Lastly, a combination of different lightweight vehicle components manufactured from
Depcik, Christopher, Gaire, Anmesh, Gray, Jamee, Hall, Zachary, Maharjan, Anjana, Pinto, Darren, Prinsloo, Arno
Empirical Investigation on the Effects of Rolling Resistance and Weight on Fuel Economy of Medium-Duty Trucks02-12-03-001608/28/2019
Abstract Vehicle rolling resistance and weight are two of the factors that affect fuel economy. The vehicle tire rolling resistance has a more significant influence than aerodynamics drags on fuel economy at lower vehicle speeds, particularly true for medium- and heavy-duty trucks. Less vehicle weight reduces inertia loads, uphill grade resistance, and rolling resistance. The influence of weight on the fuel economy can be considerable particularly in light- to medium-duty truck classes because the weight makes up a larger portion of gross vehicle weight. This article presents an empirical investigation and a numerical analysis of the influences of rolling resistance and weight on the fuel economy of medium-duty trucks. The experimental tests include various tires and payloads applied on a total of 21vehicle configurations over three road profiles. These tests assessed the sensitivity of the vehicle’s fuel economy toward rolling resistance and weight. Several experimental results showed
Liao, Gene Y., Card, Brandon, O’Malley, Molly
Determination of a Tyre’s Rolling Resistance Using Parallel Rheological Framework2019-01-506906/20/2019
Nowadays, rolling resistance sits at the core of tyre development goals because of its considerable effect on the car’s fuel economy. In contrast to the experimental method, the finite element (FE) method offers an inexpensive and efficient estimation technique. However, the FE technique is yet to be a fully developed product particularly for rolling-resistance estimation. An assessment is conducted to study the role of material viscoelasticity representation in FE, in linear and non-linear forms, through the use of Prony series and parallel rheological framework (PRF) models, respectively, on the tyre’s rolling-resistance calculation and its accuracy. A unique approach was introduced to estimate the rolling resistance according to the tyre’s hysteresis energy coefficient. The non-linear PRF choice resulted in rolling-resistance calculations that reasonably match that of the experimental work and the literature for various vertical load and inflation cases, whereas the Prony series
Aldhufairi, Hamad Sarhan, Olatunbosun, Oluremi, Essa, Khamis
Multi-Chamber Tire Concept for Low Rolling-Resistance06-12-02-000904/08/2019
Rolling-resistance is leading the direction of numerous tire developments due to its significant effect on fuel consumption and CO2 emissions considering the vehicles in use globally. Many attempts were made to reduce rolling-resistance in vehicles, but with no or limited success due to tire complexity and trade-offs. This article investigates the concept of multiple chambers inside the tire as a potential alternative solution for reducing rolling-resistance. To accomplish that, novel multi-chamber designs were introduced and numerically simulated through finite-element (FE) modeling. The FE models were compared against a standard design as the baseline. The influences on rolling-resistance, grip, cornering, and mechanical comfort were studied. The multi-chambers tire model reduced rolling-resistance considerably with acceptable trade-offs. Independent air volumes isolating the tread from sidewalls would maintain tire’s profile effectively. Different air concentration across the tire’s
Aldhufairi, Hamad Sarhan, Essa, Khamis, Olatunbosun, Oluremi
Tire Ply-Steer, Conicity and Rolling Resistance - Analytical Formulae for Accurate Assessment of Vehicle Performance during Straight Running2019-01-123704/02/2019
The aim of the paper is to provide simple and accurate analytical formulae describing the straight motion of a road vehicle. Such formulae can be used to compute either the steering torque or the additional rolling resistance induced by vehicle side-slip angle. The paper introduces a revised formulation of the Handling Diagram Theory to take into account tire ply-steer, conicity and road banking. Pacejka’s Handling Diagram Theory is based on a relatively simple fully non-linear single track model. We will refer to the linear part of the Handling Diagram, since straight motion will be considered only. Both the elastokinematics of suspension system and tire characteristics are taken into account. The validation of the analytical expressions has been performed both theoretically and after a subjective-objective test campaign. By means of the new and unreferenced analytical formulae, practical hints are given to set to zero the steering torque during straight running. Additionally, the
Lattuada, Alessandro, Mastinu, Gianpiero, Matrascia, Giuseppe
Uncertainty in Radius Determined by Multi-Point Curve Fits for Use in the Critical Curve Speed Formula2019-01-042804/02/2019
The critical curve speed formula used for estimating vehicle speed from yaw marks depends on the tire-to-road friction and the mark’s radius of curvature. This paper quantifies uncertainty in the radius when it is determined by fitting a circular arc to three or more points. A Monte Carlo analysis was used to generate points on a circular arc given three parameters: number of points n, arc angle θ, and point measurement error σ. For each iteration, circular fits were performed using three techniques. The results show that uncertainty in radius is reduced for increasing arc length, decreasing point measurement error, and increasing number of points used in the curve fit. Radius uncertainty is linear if the ratio of the standard deviation in point measurement error (σ) to the curve’s middle ordinate (m) is less than 0.1. The ratio σ/m should be less than 0.018 for a radius found using a 3-point circular fit to be within 5% of the actual value 95% of the time. Increasing the number of
Heinrichs, Bradley, Mithrush, Troy
Research on Technique for Correction of Running Resistance with Focus on Tire Temperature and Tire Thermal Balance Model2019-01-062304/02/2019
At present, measurements of running resistance are conducted outdoors as a matter of course. Because of this, the ambient temperature at the time of the measurements has a considerable impact on the measurement data. The research discussed in this paper focused on the temperature characteristic of the tires and developed a new correction technique using a special rolling test apparatus. Specifically, using a tire rolling test apparatus that made it possible to vary the ambient temperature, measurements were conducted while varying the levels of factors other than temperature that affect rolling resistance (load, inflation pressure, and speed). Next, a regression analysis was applied to the data for each factor, and coefficients for a relational expression were derived, making it possible to derive a quadratic equation for the tire rolling resistance correction formula. It was verified that the application of the new correction formula reduced variation in running resistance from 2.7
Hotaka, Takeshi, Sakai, Tomonori, Miura, Hideki
DATC spells progress for defense prototyping19AUTP02_0302/01/2019
A public-private partnership between the U.S. Army's TARDEC and SAE International is making it easier for suppliers to engage the government on military ground-vehicle technology projects. A slogging bureaucracy, miles of “red tape” and a sea of acronyms are just some of the hurdles that keep many suppliers from working with the U.S. defense industry on ground-vehicle projects. For years the government, led by the U.S. Army Tank-Automotive Research, Development and Engineering Center (TARDEC), sought to develop a streamlined procurement process. Their aim was to speed the adoption of private-sector innovations, particularly for prototype development, while expanding access for smaller, non-traditional military suppliers. A breakthrough came in 2016, when TARDEC partnered with SAE International's Industry Technologies Consortia affiliate to form the nonprofit Defense Automotive Technologies Consortium; DATC currently has 190 members-70% of which are non-traditionals. The consortium
Brooke, Lindsay
ABS Optimization for a Two-Wheeler Based on Tire-Road Friction Characteristics2019-26-001701/09/2019
Anti-lock Braking System (ABS) is a well-known active safety technology widely used in cars. Recently, it has become a mandatory safety feature for two-wheelers. In principle, ABS ensures an optimum braking performance by not allowing the tire to slip beyond a certain level. This guarantees steering stability and peak braking performance of the tire during panic braking situations. As the ABS controller depends on the tire characteristics information for its algorithm, a change in tire or pavement can vary the optimum operating range of ABS. In addition to this, motorcycle tires differ from a car tire in terms of its construction, dimension and compound. Therefore, the motorcycle tire’s performance envelope cannot be directly compared to a car tire. This work presents a methodology which aims to acquire the tire-road friction characteristics of three different tires for a study motorcycle on different friction surfaces through experimentation and estimation techniques. The optimum
Ranjan, Ashish, Srivastava, Shreyansh, Anantha, Prashanth
Investigation of Cabin Noise while Accelerating on Low Mu Track through Simulation Approach Using Full Vehicle ADAMS/Car Model2019-26-017901/09/2019
Cabin noise is a significant product quality criteria which enables the customers for product differentiation. There are various sources of cabin noise such as wind, structures(panels), engine, suspension, tire and roads. During product development phase, extensive tests has been conducted to improve vehicle dynamics behavior on various climatic conditions. One such test is accelerating vehicle on low mu or icy surface. While performing acceleration manoeuvre (tractions) on a low mu tracks, Cabin noise with source identified from front underbody & low tractive torque build up is reported. This undesirable behavior may occur due to following reason (1) Excitation of coupled modes between suspension and powertrain which induces torque fluctuation. (2) Transmissibility of various subsystem can be the reason for above problem statement. (3) Poorly chosen tire compounds and design leads to fluctuation in torque. A detailed simulation based study using ADAMS/CAR has been performed to assess
Singh, Vivek, Prasad, Tej, Srivastava, Harshit
Analysis of Effect of Tire Inflation Pressure, Inflation Fluids, Load and Speed on Tire Performance2019-26-036801/09/2019
There are various losses associated with passenger vehicle that affect its fuel economy as it is being operated. These losses include losses at engine, driveline, aerodynamic and rolling losses. While engine, driveline and aerodynamic losses are inherent with the vehicle due to large number of parts that are assembled together, rolling loss is associated with the vehicle tires and it is the only part of the vehicle that comes in contact with the road surface. The rolling resistance of inflated tires is an important component of rolling resistance to vehicle motion and contributes to vehicle fuel consumption. Hence the effect of tire parameters such as inflation pressure, speed and load are the subject of much current interest. Also effect of type of inflation fluid on tire performance is a need of investigation. This work is focused on the design and development of tire testing setup to test the tire performance parameters like rolling resistance and tire temperature by varying the
Thombare, Dhananjay Ganpati
Tire Side Force Characteristics with the Coupling Effect of Vertical Load and Inflation Pressure10-03-01-000211/09/2018
The tire vertical load and inflation pressure have great influence on tire steady- and non-steady-state characteristics and, consequently, on the vehicle handling and stability. The objective of this article is to reveal the coupling effect of tire vertical load and inflation pressure on tire characteristics and then introduce an improved UniTire side force model including such coupling effect through experimental and theoretical analysis. First, the influence of the tire vertical load and inflation pressure on the tire characteristics is presented through experimental analysis. Second, the theoretical tire cornering stiffness and lateral relaxation length model are introduced to study the underlying mechanism of the coupling effect. Then, an improved UniTire side force model including the coupling effect of tire vertical load and inflation pressure is derived. Finally, the proposed improved UniTire side force model is validated through tire steady-state and transient data. The
Guo, Konghui, Chen, Ping, Xu, Nan, Yang, Chao, Li, Fei
Comparison of Different Variable Braking Force Systems2018-01-186510/05/2018
An automobile braking system has a crucial role in the safety of the passengers and riding quality of the vehicle. The braking force mainly depends on the normal reaction on the wheel and the coefficient of adhesion between the tire and the road surface. The required braking force for a vehicle varies with the load on the vehicle. If the applied braking force is greater than the required brake force, wheel gets locked which results in increased stopping distance. In order to prevent the wheel lock at low load conditions or deficient braking force at extremely high load conditions, a variable braking force system is developed. Whenever a motorcycle is loaded, the normal reaction on the rear wheel is increased. Thus, the amount of braking force required to halt the motorcycle with minimum stopping distance and stability of the motorcycle is based on the pillion load on the motorcycle. Hence, the amount of braking force developed between the road surface and the tire is varied in the
Subramanian, Chidambaram, Vinayaga Sundaram, Ganesh
Commercial Truck and Bus SAE Recommended Procedure for Vehicle Performance Prediction and ChartingJ2188_201807 (Current)07/25/2018
This SAE Recommended Practice takes into account modern standardized methods for collecting and summarizing data that has an effect on vehicle steady-state performance, such as engine output (gross and net), transmission losses, drivetrain efficiency, vehicle aerodynamic devices for various vehicle and body configurations, as well as road surface variations and air density variations resulting from altitude and barometric effects. The procedure does not address vehicle transient performance (acceleration, braking, and cornering), because of the considerable amount of additional data required such as moment of inertia of all the rotating parts. Nor does it address vehicles with torque converters and automatic transmissions. This document is, therefore, intended for vehicles having fixed-ratio type transmissions and positive engagement clutches. Metric and ISO unit conversions are provided in the metric conversion tables at the end of this procedure (see Appendix B). Some modern vehicles
Truck and Bus Powertrain Committee
Modeling Cruise Control Initiated Wheelspin in Rear Wheel Drive Vehicles2018-01-500005/04/2018
There are driving situations in which a rear-wheel-drive vehicle, operating with an active closed-loop cruise control, can experience wheelspin and a subsequent oversteer/loss of control. The situations involve low-μ surfaces (ice), weather-related phenomenon (rear-wheel hydroplaning), slope-climbing or a combination of these external effects. Although traction control and stability control, depending on the sophistication of the system, can negate many of these situations, the active fleet contains many vehicles not equipped with these features. In the present work, we calculate the conditions under which cruise-control-initiated rear wheel spin can occur.
Metz, L. Daniel
Control Optimization of a Charge Sustaining Hybrid Powertrain for Motorsports2018-01-041604/03/2018
The automotive industry is aggressively pursuing fuel efficiency improvements through hybridization of production vehicles, and there are an increasing number of racing series adopting similar architectures to maintain relevance with current passenger car trends. Hybrid powertrains offer both performance and fuel economy benefits in a motorsport setting, but they greatly increase control complexity and add additional degrees of freedom to the design optimization process. The increased complexity creates opportunity for performance gains, but simulation based tools are necessary since hybrid powertrain design and control strategies are closely coupled and their optimal interactions are not straightforward to predict. One optimization-related advantage that motorsports applications have over production vehicles is that the power demand of circuit racing has strong repeatability due to the nature of the track and the professional skill-level of the driver. The repeatable behavior from lap
Zhu, Qilun, Song, Shixin, Tan, Xiaoping, Song, Chuanxue, Prucka, Robert
Integrated Chassis Control for Vehicle Stability under Various Road Friction Conditions2018-01-055204/03/2018
This paper presents an integrated chassis control method for vehicle stability under various road friction conditions without information on tire-road friction. For vehicle stability, vehicle with an integrated chassis control needs to cope with the various road friction conditions. One of the chassis control method under various road conditions is to determine and/or limit control inputs based on tire-road friction coefficient. The tire-road friction coefficient, however, is difficult to estimate and still a challenging task. The key idea for the proposed method without the estimation of the tire-road friction coefficient is to analyze and control vehicle states based on a tire slip angle - tire force phase plane, i.e. based on these vehicle responses: tire forces and tire slip angles of front/rear wheels. Based on the phase plane, vehicle instability is detected and the vehicle is controlled to regain the vehicle stability and maneuverability under various road conditions without
Joa, Eunhyek, Yi, Kyongsu, Bae, Hyungjune, Sohn, Kimo
Environmental and Safety Performance of Commercially-available Light-duty Vehicle Tires in North America2018-01-133604/03/2018
New technology is enabling tire manufacturers to reduce tire rolling resistance, leading to reduced fuel consumption and greenhouse gas emissions in the transportation sector. This project analyzed current relationships between the environmental and safety performance of commercially-available light-duty tire models in North America. Performance data was rated using the EC No. 1222/2009, and compared against tire price, uniform tire quality grading standards (UTQG), and other attributes. A random selection of tire models was tested, consisting of: 108 all-season, 23 studless winter, and 5 all-weather tire models. All test results were blinded for the purpose of confidentiality. Tire rolling resistance coefficients were measured using the single point ISO 28580 standard, and wet grip index values were measured according to UN-ECE Reg.117. Rolling resistance and wet grip indicators were measured using dynamic mechanical analysis (DMA). Snow and ice traction ratings were calculated
Shafique, Hamza, Richard, Brad, Christenson, Martha, Bayne, Sandra
The Method of Constructing the Diagrams of Shear Stresses in the Contact Zone of an Slipping Wheel With Soil2018-01-133504/03/2018
The process of interaction of the driving wheels of mobile energy resources with soil is considered. A computational and experimental method is proposed for plotting the shear stresses in the contact zone of the skid wheel with a supporting surface, based on the use of normal stresses obtained for specific ground conditions. The character of the interaction of the driving wheel of the tractor with various types of supporting base has been studied in detail: a dirt road, stubble, a field prepared for sowing. It is revealed that, contrary to the generally accepted ideas, the slipping wheel has practically no adhesion zone in the contact spot. After touching the tiller of the supporting surface, it immediately begins to shift backward. Therefore, when calculating the shear stresses in the contact patch of the skid wheel with the support, it is more correct to assume that the shift of the elementary points increases as they move away from the entrance to the contact zone and depends on the
Izmailov, Andrei, Revenko, Valerij, Godzhaev, Zakhid
Modeling of Tire-Wet Surface Interaction Using Finite Element Analysis and Smoothed-Particle Hydrodynamics Techniques2018-01-111804/03/2018
This paper focuses on predicting the rolling resistance and hydroplaning of a wide base truck tire (Size: 445/50R22.5) on dry and wet surfaces. The rolling resistance and hydroplaning are predicted at various inflation pressures, loads, velocities, and water depths. The wide base truck tire was previously modeled and validated using Finite Element Analysis (FEA) technique in virtual performance software (Pam-Crash). The water is modeled using Smoothed-Particle Hydrodynamics (SPH) method and Murnaghan equation of state. A water layer is first built on top of an FEA rigid surface to represent a wet surface. The truck tire is then inflated to the desired pressure. A vertical load is then applied to the center of the tire. For rolling resistance tests variable constant longitudinal speeds are applied to the center of the tire. The forces in the vertical and longitudinal directions are computed, and the rolling resistance is calculated. The effect of the longitudinal speed on rolling
El-Sayegh, Zeinab, El-Gindy, Moustafa, Johansson, Inge, Oijer, Fredrik
Wet or Dry Pavement Passenger Car Tire Peak and Locked Wheel Braking TractionJ345_201802 (Current)02/15/2018
This SAE Recommended Practice defines the best known techniques for evaluating peak and locked wheel braking traction. It covers an important phase of tire braking traction, namely, the wet or dry pavement straight ahead conditions. However, this is but a small portion of the whole field of tire traction. As test procedures are established for other phases of this complex study, additional supplementary procedures will be written. A discussion of this entire subject is contained in Appendix B to this recommended practice.
Highway Tire Committee
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