Your Selections

Tires
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Acoustic characteristics prediction and optimization of wheel resonators with arbitrary section

SAIC Motor Corporation Limited-Yimin Sun, Junlei Mao
Tongji University-Rong Guo, Tiantian Mi
  • Technical Paper
  • 2020-01-0917
To be published on 2020-04-14 by SAE International in United States
Tire cavity noise of pure electric vehicles is particularly prominent due to the absence of engine noise, which are usually eliminated by adding Helmholtz resonators with arbitrary transversal section to the wheel rims. This paper provides theoretical basis for accurately predicting and effectively improving acoustic performance of wheel resonators. A hybrid finite element method is developed to extract the transversal wavenumbers and eigenvectors, and the mode-matching scheme is employed to determine the transmission loss of the Helmholtz resonator. Based on the accuracy validation of this method, the matching design of the wheel resonators and the optimization method of tire cavity noise are studied. The identification method of the tire cavity resonance frequency is developed through the acoustic modal simulation and test. A scientific transmission loss target curve and fitness function are defined according to the noise characteristics. Combing the transmission loss prediction theory and particle swarm algorithm, the structure parameters of the wheel resonator are optimized. A remarkable attenuation of tire cavity resonance can be observed through test results.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development and Application of a Collision Avoidance Capability Metric

AAA Northern California Nevada & Utah-Paul Wells, Atul Acharya
Dynamic Research Inc.-Jordan Silberling, Joseph Kelly, John Lenkeit
  • Technical Paper
  • 2020-01-1207
To be published on 2020-04-14 by SAE International in United States
This paper describes the development and application of a newly developed metric for evaluating and quantifying the capability of a vehicle/controller (e.g., Automated Vehicle or human driver) to avoid collisions in nearly any potential scenario, including those involving multiple potential collision partners and roadside objects. At its core, this Collision Avoidance Capability (CAC) metric assesses the vehicle’s ability to avoid potential collisions at any point in time. It can also be evaluated at discrete points, or over time intervals. In addition, the CAC methodology potentially provides a real-time indication of courses of action that could be taken to avoid collisions. The CAC calculation evaluates all possible courses of action within a vehicle’s performance limitations, including combinations of braking, accelerating and steering. Graphically, it uses the concept of a “friction ellipse”, which is commonly used in tire modeling and vehicle dynamics as a way of considering the interaction of braking and turning forces generated at the tire contact patches. When this concept is applied to the whole vehicle, and the actual or estimated maximum lateral and…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigations on Headlamp and Car Body Tolerances in Real Life

Audi AG-Michael Hamm, Christian Hinterwalder
  • Technical Paper
  • 2020-01-0635
To be published on 2020-04-14 by SAE International in United States
Good Lighting is cruicial for safe driving at night. Unfortunately many parameters are contributing to the final result of the individual tolerances of car body, dynamics and headlamp: The resulting aim. The paper will collect and analyse tolerance contributors from body parameters like load, tire pressure, suspension as well as aging parameters of chassis and plastic parts.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Study on Tire Size Selection Criteria Considering Tire Bulge

Hyundai Motors Namyang Institute-Kim Juho
  • Technical Paper
  • 2020-01-1230
To be published on 2020-04-14 by SAE International in United States
The purpose of this study is to find the tire design parameter affecting Tire Impact bulge and to update part test method and to make a tool for analyzing pinch cut test. First, the parameters of bulge between tire pinch cut result and tire parameter were investigated by pinch cut test and main factor of bulge was derived form the result. Second, the parameters of bulge between tire pinch cut result and vehicle test were investigated by vehicle test and main factor of bulge was derived from the result. Last, the influence of tire pressure and vehicle weight for bulge was studied and was defined. From this study, it is possible to predict the robustness against bulge by using an analysis tool developed by this study.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Facility for Complete Characterization of Suspension Kinematic and Compliance Properties of Wheeled Military Vehicles

SEA, Ltd.-Dale Andreatta, Gary Heydinger, Anmol Sidhu, Scott Zagorski
  • Technical Paper
  • 2020-01-0175
To be published on 2020-04-14 by SAE International in United States
As part of their ongoing efforts to model and predict vehicle dynamic behavior, the US Army’s Ground Vehicle Systems Center procured a facility in two phases. The facility is called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and has a capacity covering all of the military’s wheeled vehicles, with vehicle weights to 100,000 lbs (45,400 kg), up to 150 inches wide, with any number of axles. The initial phase had the ability to measure bounce and roll kinematic and compliance properties. The SPIdER is the companion machine to the Vehicle Inertia Parameter Measuring Device (VIPER) which measures the inertia properties of vehicles of similar size. In 2015, the final phase of the SPIdER was completed. This phase includes ground plane wheel pad motion so that lateral, longitudinal, and aligning moment compliance and kinematic properties can be measured. These capabilities greatly enhance the SPIdER’s features, giving it the ability for making complete suspension and steering system kinematic and compliance measurements. Horizontal forces and aligning moments can be applied up to the limits of tire slip.…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Comparative Study on the Effects of the Tread Rubber Compounds on Tire Tractive performance on Ice

Virginia Tech-Hoda Mousavi, Corina Sandu
  • Technical Paper
  • 2020-01-1228
To be published on 2020-04-14 by SAE International in United States
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 result for the traction tests. The…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Bicycle Braking Performance Testing and Analysis

Momentum Engineering Corp.-Nicholas Famiglietti, Benjamin Nguyen, Edward Fatzinger, Jon Landerville
  • Technical Paper
  • 2020-01-0876
To be published on 2020-04-14 by SAE International in United States
The goal of this study was to determine the braking capabilities of different bicycle types, with different brake setups and applications. A variety of bicycles, including a mountain bike, beach cruiser, BMX bike, road bike, and commuter bike were used to perform brake-to-stop tests. Prior to brake testing, the bicycles were fully inspected, prepped, and documented. Details of the bicycles’ make, model, tires, wheels, brake setup, suspension setup, and preexisting damage were photographed and recorded. The standardized brake testing procedure consisted of rear only brake application and both front and rear brake application. In order to maintain brake application consistency, a single rider performed all series of the skid/brake tests at the same location, on dry asphalt. The tests were performed at an initial velocity of 9 – 20 mph. For each test, the rider accelerated to the test speed and applied maximum braking effort while maintaining a natural upright position to reduce lean. The tests were performed on a painted grid for visibility purposed in measuring skid lengths and post-test video analysis. The bicycle…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Pre-validation method of steering system by using hybrid simulation

Hyundai Motor Company-Hong Suk Chang
  • Technical Paper
  • 2020-01-0645
To be published on 2020-04-14 by SAE International in United States
In this study, the preliminary validation method of the steering system is constructed and the objective is to satisfy the target performance while minimizing the problems after the detailed design considering it in the conceptual design stage. The first consideration about steering system is how to extract the reliable steering effort for parking. The tire model commonly used in MBD has limited ability to represent deformations under heavy loads. Therefore, it is necessary to study adequate tire model to simulate the behavior due to the large deformation and friction between the ground and the tire. The two approaches related with F tire model and mathematical model are used. The second is how to extract the each link’s load in the conceptual design stage. Until now, each link’s load is derived by the actual vehicle test, and a durability analysis was performed using the pre-settled RIG test conditions. Therefore, in this study, we established the process of deriving the RIG test conditions by integrating the hydraulic system and the dynamic system without actual vehicle test. The…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Multi-Resonant Speed Piezoelectric Beam Device for Harvesting Energy from Vehicle Wheels

Oakland University-Christopher Cooley
  • Technical Paper
  • 2020-01-1236
To be published on 2020-04-14 by SAE International in United States
This work analyzes a cantilevered piezoelectric beam device for harvesting energy from the simultaneous rotation and translational vibration of vehicle wheels. The device attaches to the wheel rim so that it displaces tangentially during operation. A lumped-parameter analytical model for the coupled electromechanical system is derived. The device has one natural frequency that is speed-dependent because of centripetal acceleration affecting the total stiffness of the device. Even though the device has one natural frequency, it experiences three resonances as the rotation speed varies. One resonance occurs when the rotation speed coincides with the speed-dependent natural frequency of the device. The other two resonances are associated with excitations from the vibration of the vehicle wheel. The device’s parameters are chosen so that these three resonances occur when the wheel travels near 30 mph, 55 mph, and 70 mph. There are two excitation frequencies that give these resonant speeds, and both choices differ from the conventional selection of the device’s natural frequency to match the excitation frequency. Instead, the device’s natural frequency must be either above or…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Wake study on isolated, detailed and rotating car wheels

Audi AG-Lukas Haag, Vincent Zander
Technische Universitat Munchen-Jan Reiß, Jonas Sebald, Thomas Indinger
  • Technical Paper
  • 2020-01-0686
To be published on 2020-04-14 by SAE International in United States
Wheels on passenger vehicles cause about 25% of the aerodynamic drag. The interference of rims and tires in combination with the rotation result in strongly turbulent wake regions with complex flow phenomena. This wake structures interact with the flow around the vehicle. To understand the wake structures of wheels and their aerodynamic impact on the aerodynamic drag of the vehicle, the complexity was reduced by investigating a standalone tire in the windtunnel. Besides the influence of geometry changes on the acting forces, the wake region behind the wheel is investigated via Particle Image Velocimetry (PIV). The average flow field behind the investigated wheels is captured with this method and offers insight into the flow field. The investigation of the wake region allows to attribute changes in the flow field to the change of tires and rims. Due to increased calculation performance sophisticated CFD simulations can capture detailed geometries like the tire tread and the movement of the rim. Therefore, the wake investigation via PIV is a usable basis to compare it to results of such…