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Effect of Tyre Inflation Pressure on Rolling Resistance : Comparing the Values of Coefficient of Rolling Resistance and Rolling Resistance at Variable Tyre Inflation Pressure

International Centre for Automotive Technology-Siddharth Tripathi, Amit Kumar Karwal, Mukund Mishra, Dushyant Wazir
  • Technical Paper
  • 2019-28-2415
Published 2019-11-21 by SAE International in United States
1Rolling 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.
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Suspension hard points optimisation

Altair Engineering-AshithKumar Shetty
  • Technical Paper
  • 2019-28-2419
Published 2019-11-21 by SAE International in United States
Objective This paper explores the usage of Altair simulation driven optimisation process, Front Suspension hard points of a sedan Car model are optimised for specific target toe curves using MotionView, MotionSolve and HyperStudy This process gives the optimal hard point values to match the target curves without much iterations. Methodology Parametric Multibody model of the front end of sedan is built in MotionView. To Carry out optimisation HyperStudy is used where few of the suspension hard points which affect the toe curves are chosen as design variable. For the chosen Design variables upper and lower bound limits are specified. Ride, Roll and lateral force tests are performed. Optimisation is performed using HyperStudy where it iterates the suspension hard points to match the target toe curves. Each iteration response can be visualized in HyperStudy and can be compared with the target toe curve. Hyperstudy points the iteration which is closest to the Target curve Advantage • Quick model setup and run time • Parametric model allows quick change in design • Insight at early design stage…
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Transient Response Analysis and Synthesis of an FSAE Vehicle using Cornering Compliance

SRM Institute of Science and Technology-Nanthakumar Ajd, Pranav Suresh, Shubham Subhnil, Vasanthkumar CH
  • Technical Paper
  • 2019-28-2400
Published 2019-11-21 by SAE International in United States
OBJECTIVE Race vehicles are designed to achieve higher lateral acceleration arising at cornering conditions. A focused study on the steady state handling of the car is essential for the analysis of such conditions. The transient response analysis of the car is also equally important to achieve best driver-car relationship and to quantify handling in the range suitable for a racing car. This research aims to investigate the design parameters responsible for the transient characteristics and optimize those design parameters. This research work examines the time-based analysis of the problem to truly capture the non-linear dynamics. Apart from tires, chassis can be tuned to optimize vehicle handling and hence the response times. METHODOLOGY To start with, the system is modelled with governing parameters and simulation is carried out to set baseline configurations. Steady state and transient handling simulations run independent of each other with independent logic, coded on MATLAB. The static testing of the chassis is carried over using a Kinematic & Compliance (K & C) testing rig to get Compliance Budget and hence the calculated…
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Evaluating Effects of Roll Stiffness Change at Front and Rear Axles on Vehicle Maneuverability and Stability

Maruti Suzuki India, Ltd.-Eric Pranesh Reuben, Raghav Budhiraja, Sreeraj N, Rakesh K, Amardeep Singh
  • Technical Paper
  • 2019-28-2406
Published 2019-11-21 by SAE International in United States
To cater the push towards “Vehicle Light Weighting”, both sprung and unsprung mass are being reduced. This results in reduced stiffness and thus has a profound undesirable effect on the overall vehicle handling. To understand the effect of different reduction ratios of sprung to unsprung mass; it is desired to understand how changes in stiffness affect the overall vehicle handling characteristics. Therefore, the study was conducted to experiment with different values of roll stiffness, at both front and rear axles and comparing the frequency response and phase change of Yaw Gain observed through a Pulse Input test. The present work is further correlated with subjective feedback to predict the shift in vehicle balance and handling characteristics.
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Rolling Circumference Index Groups for Agricultural Tractor Drive Tires

MTC8, Tire and Rim
  • Ground Vehicle Standard
  • J2523_201911
  • Current
Published 2019-11-20 by SAE International in United States

This SAE Standard is established for the following purpose:

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Countering the Destabilizing Effects of Shifted Loads through Pneumatic Suspension Design

SAE International Journal of Vehicle Dynamics, Stability, and NVH

Virginia Tech, USA-Yang Chen, Mehdi Ahmadian
  • Journal Article
  • 10-04-01-0001
Published 2019-11-08 by SAE International in United States
This article proposes a novel approach to reduce the destabilizing impacts of the shifted loads of heavy trucks (due to improper loading or liquid slosh) by pneumatic suspension design. In this regard, the pneumatically balanced suspension with dual leveling valves is introduced, and its potential for the improvement of the body imbalance due to the shifted load is determined. The analysis is based on a multi-domain model that couples the suspension fluid dynamics, shifted-load impacts, and tractor-semitrailer dynamics. Truck dynamics is simulated using TruckSim, which is integrated with the pneumatic suspension model developed in AMESim. This yields a reasonable prediction of the effect of the suspension airflow dynamics on vehicle dynamics. Moreover, the ability of the pneumatic suspension to counteract the effects of two general shifted loads - static (rigid cargo) and dynamic (liquid) - is studied. The simulation results indicate that the dual-leveling-valve suspension results in a reduction in roll angle and roll rate of the vehicle body for both static and dynamic load-shifting cases, as compared to the conventional single-leveling-valve suspension. Suppression of…
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Continental Tire rolls towards a smart-and-connected future

Automotive Engineering: October 2019

Stuart Birch
  • Magazine Article
  • 19AUTP10_09
Published 2019-10-01 by SAE International in United States

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.

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Surface Treatment Could Improve Refrigeration Efficiency

  • Magazine Article
  • TBMG-35131
Published 2019-09-01 by Tech Briefs Media Group in United States

Unlike water, liquid refrigerants and other fluids that have a low surface tension spread quickly into a sheet when they come into contact with a surface. For many industrial processes, it would be better if the fluids formed droplets that could roll or fall off the surface and carry heat away with them.

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Speed Planning and Prompting System for Commercial Vehicle Based on Real-Time Calculation of Resistance

SAE International Journal of Commercial Vehicles

Wuhan University of Technology, China-Zhaocong Sun, Zhimin Li, Jinyi Xia, Gangfeng Tan
  • Journal Article
  • 02-12-03-0013
Published 2019-06-25 by SAE International in United States
When commercial vehicles drive in a mountainous area, the complex road condition and long slopes cause frequent acceleration and braking, which will use 25% more fuel. And the brake temperature rises rapidly due to continuous braking on the long-distance downslopes, which will make the brake drum fail with the brake temperature exceeding 308°C [1]. Meanwhile, the kinetic energy is wasted during the driving progress on the slopes when the vehicle rolls up and down. Our laboratory built a model that could calculate the distance from the top of the slope, where the driver could release the accelerator pedal. Thus, on the slope, the vehicle uses less fuel when it rolls up and less brakes when down. What we do in this article is use this model in a real vehicle and measure how well it works. Thus, to improve the safety and economy of commercial vehicles on mountainous areas, the Vehicle Speed Planning and Prompting System based on real-time calculation of resistance is established. The system consists of four parts: Hardware on Vehicle, Microcontroller Unit…
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Development of an Accelerated Test for Tire Flat-Spotting

NissanTechnical Center North America-Farokh Kavarana, Scott Fritz
Published 2019-06-05 by SAE International in United States
Tire flat-spotting occurs when tires remain in a loaded condition without rolling for an extended period of time, and can be temporary or permanent depending on the length of storage, vehicle loading and environmental factors. Tire non-uniformity caused from flat-spots often induce shake and shimmy vibration in vehicles due to increased tire-wheel force variation input into the chassis. This results in increased warranty costs for OEMs and tire suppliers and customer dis-satisfaction in third-party quality surveys such as J. D. Power IQS. Flat-spotting is of particular concern for slow-moving vehicle inventory parked for long periods at plants and/or dealership lots.OEMs often stipulate or recommend inventory storage practices for dealers that require physical movement of vehicles at some set duration to reduce the risk of tires developing permanent flat-spots. OEMs also provide component level flat-spotting requirements to tire manufacturers during sourcing and specification timing to secure their internal requirements and targets. The study in this paper initially determined real-world flat-spotting levels on an actual vehicle during the adverse summer months of Arizona. Tire uniformity measured on…
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