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Viewing 1 to 30 of 2043
2017-03-28
Technical Paper
2017-01-1509
L. Daniel Metz
Abstract We examine the characteristics, properties and potential idealized delamination failure modes of tires in this work. Calculations regarding tire failure stresses during tire failure scenarios, as well as during normal operation, are made. The calculations, though idealized, indicate that large chassis loads can result from the idealized failures.
2017-03-28
Technical Paper
2017-01-1504
Peter Tkacik, Zachary Carpenter, Aaron Gholston, Benjamin James Cobb, Sam Kennedy, Ethan Blankenship, Mesbah Uddin, Surya Phani Krishna Nukala
Wind tunnel aerodynamic testing involving rolling road tire conditions can be expensive and complex to set up. Low cost rolling road testing can be implemented in a 0.3m2 Eiffel wind tunnel by modifying a horizontal belt sander to function as a moving road. This sander is equipped with steel supports to hold a steel plate against the bottom of the wind tunnel to stabilize the entire test section. These supports are bolted directly into the cast iron sander frame to ensure minimal vibrational losses or errors during testing. The wind tunnel design at the beginning of the project was encased in a wooden box which was removed to allow easier access to the test section for installation of the rolling road assembly. The tunnel was also modified to allow observers to view the testing process from various angles.
2017-03-28
Technical Paper
2017-01-1626
Tomas Poloni, Jianbo Lu
Abstract This paper proposes a method to make diagnostic/prognostic judgment about the health of a tire, in term of its wear, using existing on-board sensor signals. The approach focuses on using an estimate of the effective rolling radius (ERR) for individual tires as one of the main diagnostic/prognostic means and it determines if a tire has significant wear and how long it can be safely driven before tire rotation or tire replacement are required. The ERR is determined from the combination of wheel speed sensor (WSS), Global Positioning sensor (GPS), the other motion sensor signals, together with the radius kinematic model of a rolling tire. The ERR estimation fits the relevant signals to a linear model and utilizes the relationship revealed in the magic formula tire model. The ERR can then be related to multiple sources of uncertainties such as the tire inflation pressure, tire loading changes, and tire wear.
2017-03-28
Technical Paper
2017-01-1427
Daniel Koch, Gray Beauchamp, David Pentecost
Abstract Tire disablement events can cause a drag force that slows a vehicle. In this study, the magnitude of the deceleration was measured for different phases of 29 high speed tire tread separation and air loss tests. These deceleration rates can assist in reconstructing the speed of a vehicle involved in an accident following a tire disablement.
2017-03-28
Technical Paper
2017-01-1505
Andreas Hackl, Wolfgang Hirschberg, Cornelia Lex, Georg Rill
Abstract The present technical article deals with the modeling of dynamic tire forces, which are relevant during interactions of safety relevant Advanced Driver Assistance Systems (ADAS). Special attention has been paid on simple but effective tire modeling of semi-physical type. In previous investigations, experimental validation showed that the well-known first-order Kelvin-Voigt model, described by a spring and damper element, describes good suitability around fixed operation points, but is limited for a wide working range. When aiming to run vehicle dynamics models within a frequency band of excitation up to 8 Hz, these models deliver remarkable deviations from measured tire characteristics. To overcome this limitation, a nonlinear Maxwell spring-damper element was introduced which is qualified to model the dynamic hardening of the elastomer materials of the tire.
2017-03-28
Technical Paper
2017-01-1551
Charlie Lew, Nath Gopalaswamy, Richard Shock, Bradley Duncan, James Hoch
Abstract The aerodynamics of a rotating tire can contribute up to a third of the overall aerodynamic force on the vehicle. The flow around a rotating tire is very complex and is often affected by smallest tire features. Accurate prediction of vehicle aerodynamics therefore requires modeling of tire rotation including all geometry details. Increased simulation accuracy is motivated by the needs emanating from stricter new regulations. For example, the upcoming Worldwide harmonized Light vehicles Test Procedures (WLTP) will place more emphasis on vehicle performance at higher speeds. The reason for this is to bring the certified vehicle characteristics closer to the real-world performance. In addition, WLTP will require reporting of CO2 emissions for all vehicle derivatives, including all possible wheel and tire variants. Since the number of possible derivatives can run into the hundreds for most models, their evaluation in wind tunnels might not be practically possible.
2017-03-28
Technical Paper
2017-01-1503
Jared Johan Engelbrecht, Tony Russell Martin, Piyush M. Gulve, Nagarjun Chandrashekar, Amol Dwivedi, Peter Thomas Tkacik, Zachary Merrill
Abstract Most commercial heavy-duty truck trailers are equipped with either a two sensor, one modulator (2S1M) or four sensors, two modulator (4S2M) anti-lock braking system (ABS). Previous research has been performed comparing the performance of different ABS modules, in areas such as longitudinal and lateral stability, and stopping distance. This study focuses on relating ABS module type and wheel speed sensor placement to trailer wheel lock-up and subsequent impact to tire wear for tandem axle trailers with the Hendrickson air-ride suspension. Prior to tire wear inspection, functionality of the ABS system was testing using an ABS scan tool communicating with the SAE J1587 plug access port on the trailer. Observations were documented on trailers using the 2S1M system with the wheel speed sensor placed on either the front or rear axle of a tandem pair.
2017-03-28
Technical Paper
2017-01-0436
Tianjun Zhu, Bin Li
Abstract A new extended planar model for multi-axle articulated vehicle with nonlinear tire model is presented. This nonlinear multi-axle articulated vehicle model is specifically intended for improving the model performance in operating regimes where tire lateral force is near the point of saturation, and it has the potential to extend the specific axles model to any representative configuration of articulated vehicle model. At the same time, the extended nonlinear vehicle model can reduce the model's sensitivity to the tire cornering coefficients. Firstly, a nonlinear tire model is used in conjunction with the 6-axle planar articulated vehicle model to extend the ranges of the original linear model into the nonlinear regimes of operation. Secondly, the performance analysis of proposed nonlinear vehicle model is verified through the double lane change maneuver on different road adhesion coefficients using TruckSim software.
2017-03-28
Journal Article
2017-01-1502
Madeline Harper, Janice Tardiff, Daniel Haakenson, Maria Joandrea, Matthew Knych
Abstract Tire manufacturers have long grappled with the challenge of balancing the conflicting tire attributes of traction, rolling resistance, and treadwear. Improvements to one of these “magic triangle” attributes often comes at the expense of the other attributes. Recent regulations have further increased the pressure on manufacturers to produce optimized tires with minimal performance compromises. In order to meet this challenge, the tire industry is looking to new material systems beyond the traditional tire tread components. Polymeric materials beyond the base elastomers and processing oils used in tread provide opportunities to modify the physical and viscoelastic properties of tread. In this study, various polymeric materials were evaluated as additives in a model tire tread formulation. Hydrocarbon resin, high styrene resin, and thermoplastic styrene elastomers were added to the model formulation at various loading levels and through various addition strategies.
2017-03-28
Journal Article
2017-01-1507
Prashanta Gautam, Yousof Azizi, Abhilash Chandy
Abstract Tire noise is caused due to the complex interactions between the rotating tire and the road surface at the tire/road interface. It is usually caused due to a combination of individual noise generation mechanisms, which can either be structural or air-borne. The influence of each of these noise generation mechanism may vary, depending on various conditions such as tire design, road surface and operating conditions. Due to the many variables that affect the noise generation mechanisms in tires, it is usually a very complex task to isolate and categorize those that are present in the overall tire/road noise spectrum. Various approaches are used to categorize noise generation mechanisms in tires. In this paper, a statistical model based on the assumption that the tire noise acoustic pressure at a specific frequency band is related to the vehicle speed, is used, in order to study tire noise at different speeds.
2017-03-28
Journal Article
2017-01-1506
Johannes Wiessalla, Yiqin Mao, Frank Esser
Abstract An intervention of vehicle stability control systems is more likely on slippery surfaces, e.g. when the road is covered with snow or ice. Contrary to testing on dry asphalt, testing on such surfaces is restricted by weather and proving grounds. Another drawback in testing is the reproducibility of measurements, since the surface condition changes during the tests, and the vehicle reaction is more sensitive on slippery surface. For that, simulation enables a good pre-assessment of the control systems independent from testing conditions. Essential for this is a good knowledge about the contact between vehicle and road, meaning a good tyre model and a reasonable set of tyre model parameters. However, the low friction surface has a high variation in the friction coefficient. For instance, the available lateral acceleration on scraped ice could vary between 0.2 and 0.4 g within a day. These facts lead to the idea of using generic tyre parameters that vary in a certain range.
2017-03-28
Journal Article
2017-01-1558
Jose Velazquez Alcantar, Francis Assadian, Ming Kuang
Abstract Hybrid Electric Vehicles (HEV) offer improved fuel efficiency compared to their conventional counterparts at the expense of adding complexity and at times, reduced total power. As a result, HEV generally lack the dynamic performance that customers enjoy. To address this issue, the paper presents a HEV with eAWD capabilities via the use of a torque vectoring electric rear axle drive (TVeRAD) unit to power the rear axle. The addition of TVeRAD to a front wheel drive HEV improves the total power output. To further improve the handling characteristics of the vehicle, the TVeRAD unit allows for wheel torque vectoring at the rear axle. A bond graph model of the proposed drivetrain model is developed and used in co-simulation with CarSim. The paper proposes a control system which utilizes tire force optimization to allocate control to each tire. The optimization algorithm is used to obtain optimal tire force targets to at each tire such that the targets avoid tire saturation.
2017-03-28
Technical Paper
2017-01-0413
Mustafa Ali Arat, Emmanuel Bolarinwa
Abstract Most ground vehicles related accidents occur when the friction demand to perform a maneuver with a certain vehicle and tires exceeds the coefficient of friction of the pavement surface. As generally known, the forces and moments acting on the vehicle body are mainly generated at the tire-road surface interface. The common characteristics of tire forces on any surface include a linear region where the forces vary linearly with respect to the relative slip values; and a nonlinear region where the forces saturate and may even start decreasing. The experience of most of the daily drivers on the roads is limited within this linear region where the dynamic behavior of the vehicle remains proportional to the driver’s inputs. Therefore, an unexpected change in tire or surface characteristics (due to a change in surface friction, large driver inputs, etc.) may easily cause the driver to panic and/or to lose his/her ability to maintain a stable vehicle.
2017-03-28
Technical Paper
2017-01-0414
Bin Li, Xiaobo Yang, James Yang, Yunqing Zhang, Zeyu Ma
Abstract In this paper, a detailed three dimensional (3D) flexible ring tire model is first proposed which includes a rigid rim with thickness, different layers of discretized belt points and a number of massless tread blocks attached on the belt. The parameters of the proposed 3D tire model can be divided into in-plane parameters and out-of-plane parameters. In this paper, the relationship of the in-plane parameters between the 3D tire model and the 2D tire model is determined according to the connections among the tire components. Based on the determined relationship, it is shown that the 3D tire model can produce almost the same prediction results as the 2D tire model for the in-plane tire behaviors.
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.
2016-11-08
Technical Paper
2016-32-0054
Barath Mohan, KVM Raju, Sai Praveen Velagapudi, Chandramouli Padmanabhan
The aim of the present study is to develop feasible test methods to measure the lateral force characteristics of motorcycle tires. In this work, new experimental procedures are developed to estimate the lateral friction coefficient and lateral stiffness characteristics of motorcycle tires. A fairly accurate tire model is developed using the measured lateral force characteristics. Based on this tire model, the steer behavior and the cornering limits of the motorcycle are estimated using an analytical model of the vehicle. The results are validated with experimental data. The test methods proposed are shown to be adequate to estimate tire characteristics that are important for tire development and is less expensive compared to the standard testing facilities available.
2016-11-08
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.
2016-10-25
Technical Paper
2016-36-0172
João Fernando Mendes Amparo, Marcos Rogério Santos Barbetti, Paulo Alexandre Galarce Zavala, George Ballardie, Roberto Moriya
Abstract This paper has the objective to present the study made on a front wheel drive passenger car with “3 Points Pendular Mounts System” to minimize the “Power Hop effect” (powertrain forced oscillation) and reduce the loads on Powertrain Mounts System. In this study, we used the Taguchi Method (Design of Experiments) to optimize the number of tests performed to evaluate the influence of powertrain mounts system design characteristics, as well as axle shafts stiffness, and tire/wheels assemblies size. The data acquisition work was all done in a physical hardware (vehicle) on test track used instrumented parts and load cells. Accelerometers were used in previous tests to get qualitative understanding of the behavior of all interface components (mounts and wheels hubs) during the power hop event.
2016-10-25
Technical Paper
2016-36-0309
Adriano Schommer, André Ogliari, Mario Martins
Abstract In the way of achieving maximum performance of a racecar several aspects of it have to be optimized. The whole picture of vehicle performance involves crossing data to find relationship among systems and identifying trends, pitfalls and optimum points. In this paper, a straightforward software tool for tire data analysis is developed and described. The software aims to integrate tire data analysis in early stages of the development process of a Formula SAE racecar. In addition, it is thought to be a learning environment to fresh team members. To establish and achieve the necessary goals, an affordancebased model was used to elicit user needs. Regarding the tires, it was possible to precisely point out what data is required to quickly fit a Pacejka tire mode and to cross raw tire data of different tires and preview the steady state balance of a vehicle.
2016-09-27
Technical Paper
2016-01-8028
Chao Yang, Nan Xu, Konghui Guo
Abstract This paper focuses on the modeling process of incorporating inflation pressure into the UniTire model for pure cornering. Via observing and manipulating the tire experimental data, the effects of inflation pressure on the tire cornering property are analyzed in detail, including the impacts on cornering stiffness, the peak friction coefficient, the curvature of transition region and the pneumatic trail. And the brief mechanism explanations are also given for some of these impacts. The results show that some effects of inflation pressure are similar to that of vertical load on the non-dimensional tire cornering property, and there are strong interactive effects between the two operating conditions. Therefore, in order to obtain concise expressions, the inflation pressure is incorporated into the UniTire tire model by analogy with the expressions for vertical load, and the interactive effects are also taken into account.
2016-09-27
Technical Paper
2016-01-8037
Nan Xu, Konghui Guo, Yiyang Yang
Abstract The tire mechanics characteristics are essential for analysis and control of vehicle dynamics. Basically, the effects of sideslip, longitudinal slip, camber angle and vertical load are able to be represented accurately by current existing tire models. However, the research of velocity effects for tire forces and moments are still insufficient. Some experiments have demonstrated that the tire properties actually vary with the traveling velocity especially when the force and moment are nearly saturated. This paper develops an enhanced brush tire model and the UniTire semi-physical model for tire forces and moments under different traveling velocities for raising need of advanced tire model. The primary effects of velocity on tire performances are the rubber friction distribution characteristics at the tire-road interface.
2016-09-27
Journal Article
2016-01-8029
Chrysostomos-Alexandros Bekakos, George Papazafeiropoulos, Dan J. O'Boy, Jan Prins, George Mavros
Abstract A novel semi-analytical solution has been developed for the calculation of the static and dynamic response of an off road tire interacting with a deformable terrain, which utilizes soil parameters independent of the size of the contact patch (size-independent). The models involved in the solution presented, can be categorized in rigid and/or pneumatic tires, with or without tread pattern. After a concise literature review of related methods, a detailed presentation of the semi-analytical solution is presented, along with assumptions and limitations. A flowchart is provided, showing the main steps of the numerical implementation, and various test cases have been examined, characterized in terms of vertical load, tire dimensions, soil properties, deformability of the tire, and tread pattern. It has been found that the proposed model can qualitatively capture the response of a rolling wheel on deformable terrain.
2016-09-27
Journal Article
2016-01-8039
Rui He, Emilio Jimenez, Dzmitry Savitski, Corina Sandu, Valentin Ivanov
Abstract Tire modeling plays an important role in the development of an Active Vehicle Safety System. As part of a larger project that aims at developing an integrated chassis control system, this study investigates the performance of a 19” all-season tire on ice for a sport utility vehicle. A design of experiment has been formulated to quantify the effect of operational parameters, specifically: wheel slip, normal load, and inflation pressure on the tire tractive performance. The experimental work was conducted on the Terramechanics Rig in the Advanced Vehicle Dynamics Laboratory at Virginia Tech. The paper investigates an approach for the parameterization of the Dugoff tire model based on the experimental data collected. Compared to other models, this model is attractive in terms of its simplicity, low number of parameters, and easy implementation for real-time applications.
2016-09-27
Technical Paper
2016-01-8027
Stefan Steidel, Thomas Halfmann, Manfred Baecker, Axel Gallrein
Abstract Rolling resistance and tread wear of tires do particularly influence the maintenance costs of commercial vehicles. Although tire labeling is established in Europe, it is meanwhile well-known that, due to the respective test procedures, these labels do not hold in realistic application scenarios in the field. This circumstance arises from the development phase of tires, where the respective performance properties are mainly evaluated in tire/wheel standalone scenarios in which the wide range of usage variability of commercial vehicles cannot be considered adequately. Within this article we address a method to predict indicators for rolling resistance and tread wear of tires in realistic application scenarios considering application-based factors of influence like specific customers, operation circumstances, regional dependencies, fleet specific characteristics etc.
2016-06-15
Journal Article
2016-01-1827
Giorgio Bartolozzi, Marco Danti, Andrea Camia, Davide Vige
Abstract The time to market in the automotive industry is constantly decreasing pushing the carmaker companies to increase the efforts in numerical simulations and to decrease the number of prototypes. In the NVH field, this time constraint reflects in moving the well-established finite element simulations towards the so called “full-vehicle simulations”. Specifically, the CAE techniques should be able to predict the complete behavior of the vehicles in mission conditions, so to reproduce some usual tests, such as the “coast down” test on different roads. The aim of this paper is to present a methodology to improve rolling noise simulations exploiting an integrated full-vehicle approach. An accurate modeling of all the subsystems is needed, with particular attention to the wheels and the suspension systems. Therefore, the paper firstly covers the modeling approach used to obtain the FE models of tires and suspension system.
2016-05-11
Technical Paper
2016-36-0068
Arthur Larocca, Pablo Yugo Yoshiura Kubo, Dayane Rosa Buss, Luis Fernando de Mello Welin
Abstract One of the major challenges on the automotive industry is how to delineate a set of representative and real road loads, for reliability and efficiency during the validation stage on the development process. While several previous studies presented evaluations and results of the tire inflation pressure influence on the fuel consumption, driver comfort, vertical load and braking and handling performance, the objective of this work is to assess the influence of the tire pressure on the forces applied to a commercial vehicle’s steering system. In this regard, the steering link-rod of a truck has been instrumented and used as a load cell, in order to quantify the forces applied to the vehicle’s pitman arm on different tire inflation pressures. The measurements were performed in a static dry-park (lock-to-lock) maneuver and by decreasing the tire inflation pressure of the vehicle’s front loaded axle (6 tons) from 110 psi (7.6 bar) to 50 psi, in steps of 10 psi.
2016-04-05
Technical Paper
2016-01-1565
Joydeep Banerjee, John McPhee
Abstract Dynamic modelling of the contact between the tires of automobiles and the road surface is crucial for accurate and effective vehicle dynamic simulation and the development of various driving controllers. Furthermore, an accurate prediction of the rolling resistance is needed for powertrain controllers and controllers designed to reduce fuel consumption and engine emissions. Existing models of tires include physics-based analytical models, finite element based models, black box models, and data driven empirical models. The main issue with these approaches is that none of these models offer the balance between accuracy of simulation and computational cost that is required for the model-based development cycle. To address this issue, we present a volumetric approach to model the forces/moments between the tire and the road for vehicle dynamic simulations.
2016-04-05
Technical Paper
2016-01-1652
Jungmin Na, Gibin Gil
Abstract This paper presents a new method to find the tire cornering characteristics that satisfy the required handling performance of a vehicle in the early tire development process. The tire cornering characteristics should be considered in the sense of not only absolute levels but also balance between front and rear tires in order to satisfy handling performance of a vehicle. As a result, it is difficult to find the appropriate tire characteristics when trial-and-error approach is used. In this study, the virtual optimization technique is applied to find the required tire cornering characteristics in more efficient way. The optimization framework consists of a vehicle dynamic simulation tool to predict the handling performance of a vehicle and an optimization tool to find the optimal solution. The objective function and the constraints are defined in terms of vehicle handling objective parameters associated with the subjective assessment.
2016-04-05
Technical Paper
2016-01-0446
Chen Liang, Guolin Wang, Zhou Zheng
Abstract A 3D finite element (FE) model of a radial tire 205/55R16, established using ABAQUS software, is utilized to simulate tire force and moment properties. Drum tests are designed to validate the FE model’s reliability. To investigate the impacts of PCR contour design theory on tire force and moment, a modified string balance contour theory is presented. Based on string balance contour theory, it simplifies the shape of belt pressure share ratio as a trapezium. Besides, a program for calculating tire contour curve is compiled using MATLAB software. Applying different belt pressure share ratios, diverse tire contours are designed. One of the contours is selected according to its positive effect on cornering stiffness in simulation.
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