DOCSLIB.ORG

A Hybrid Computer Model of Tire Shear Force

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Hybrid Computer Model of Tire Shear Force A HYBRID COMPUTER MODEL OF TIRE SHEAR FORCE GENERATION Hans B. Pacejka December 1971 A Study Sponsored by the Automobile Manufacturers Association LIST OF CONTENTS Introduction 2. Brush-Type Tire Model 3. Model with Flexible Carcass Instabilities 5. References,. Appendix I List of Terminology Appendix I1 Non-Dimensional Quantities Non-Dimensional Equations Appendix I11 Digital Programs ~naloiand Logic Circuits Appendix IV Functions and Parameters 1. INTRODUCTION In this report a technique will be discussed which offem hope for investigating and simulating tire models which can be considerably more complex than existing models used in connection with the study of tire shear force generation. The simulation of the behavior of two different tire models will be discussed :in this report. Reference [l] gives a concise description of this i:nvesti- gation. As often is the case, tackling a problem becomes easier when using a method which comes closer to the way nature "solves" the problem. Frank (Ref.'[2]) was the first to recognize the potentials of following a material element of the tire in its motion through the contact range and the rest of the tire circumference. The material element he elected to follow was part of the beam or string. The differential equation governing this motion has an unstable solution and a special iterative method was devisedl for obtaining a solution ';hr;t fits the boundary conditions, Fr~~nk restricted himself to pure sideslip (no braking or driving force) and a constant friction coefficient, In his doctoral thesis, Trlilluneit proposed follo;h;ing a certain element of tread during its motion through the cogtact patch (Ref. [3]). The base of the elastic elennelzt is asscs:ed to move alcng a straight line and the tire model that is assumed is essentially a brush type with rigid carcass. The friction coefficient \vas considered in Willumeitls st,:tdy to -ri3r:; :.:ith ~lldii:~~c~3zda~5both lon~ltudinaland lateral zi~F- -,-7q ~~1-~~~~e.1ifi~;~ ~CCOL~Y?~. The resultins equations of motion . ' ' 1 C -. ?-. - ,, 2;-?L- ,\I' 2 L- . - ?L .-. D The "tread element following" method has been adopted in modified form for our investigation and it has been extended to a model exhibiting carcass elasticity. The hybrid computer appears to be the computational device best suited to solve the problem. In addition to steady-state motions, transient motions may be considered. First, a relatively simple model which is identical to .the model developed in Reference [4:] and which will be designated as tIhe brush type model, will be considered. In the present study the pressure distribution and friction coefficient can be chosen according to experimental findings. By proper selection of parameter values the model is expected to give satisfactory results. These parameters mag be taken as functions of vertical load, speed of travel, and road contamination state. This relatively s imp :le mode 1 thought to be useful mainly in cormectio n with the sirnulistion of the motion of a complete vehicle. The relatively slowly var:ying motions of the automobile may be calculated by the digital computer wh.en the hybrid configuration is used. The rapid motions of the tread element when running through the contact area the analog computer. Some of the functions usea in the latter simulation may also be computed by the digital the vertical pressure distribution and thus with load transfer. When the speed of travel varies -7 ccr-,,,-aey2.z p,-,L,--~~:_ y3 -. CI-.:?sic;ulati.sr: ?:A;?, also the coefficient of , + *- , . , ., - -- 7, P.,>.. -4.; -.,, -< . .,: (., 1'7 :> 187,- . -- -i v...i .. ,,,,, - lc: oe ug>nt?,?.du:'i;:g th3.t rur~. parameters. The effect of such parameters as carcass zeometry and aaterial properties is represented by an influence or Green function. It will also be demonstr3ated that the response to camber angle can be sirnu1at;ed by this model in a natural manner. ?4oreover, the introduction of carcass compliance creates the possibility of examining the response to time-varying wheel-axle motion inputs. The wavelength should be chosen large with respect to the contract length. By increasing the numbzr of tread ele- ments which are followed simultaneously during one passage and by consid2ring more than one row of tread elements each exhibiting different contact lengths and pressure distributions (functions of vertical loa6, slip ang:Le, camber angle, etc.), the model approaches the nearly perfect representation of the real tire. Note, however, that mass and hysteresis of the tire b0d.y has not been included. High flqequency motions are as yet dis- regarded. The approximate theory of high frequency response de- veloped in Reference [5] may give an indication in which direction the nrodel must be modified in order to cover also this aspect of tire response. The first mod21 to be treated consists of a rigid czrcass provided xith a row of el~stictread ele~entsv13ich contact the road surface over the length where the vertical pressu-e possesses a positive value. Of the large number of elements present in the contact range only one ':ii:Ll be follo7red during its passage through the contact pzitch. Fcr steady-state notions the deflections and shear forces at a x-coordinate (i.e., at a certain distance behind or ahead of the vertical plane through the wheel-axle) do not change 'dith time. Consequentl-y , the integral of shear forces encountered by one element when rur-ning through the contact patch produces $he total forces and moment acting from ground to tire. Under the influence of longitudinal and lateral slip, the element (Figure 1) which may show different stiffnesses in lateral (8) and longitudinal (x) directions, undergoes a complex variation of deflections. The decaying friction soefficient function (Fi~ure2) causes the motion to become unstable. in practice, this is reflected in the often observed slip-stick phenomenon. The model's tread eleinent exhibits both mass (necessary for ar: oscillating rno'cion) and damping (for stabilizing the not lo^.). For the sake of simplicity, it is assumed that u is a continuoss function of sliding splaed, V s ' and approaches zero when Vc+O. u The base point, E, of' the elastic element which is the point ., .A :r? ?. 2 (2; <-P-c-,,L 2 - *..- -- -l.~-C zt~acr:ec! to tr,c cc~c2:: 171;dz.e 3), xoves ill 7 ?..A? -. \ 1 L .-. - , .-' -- - p 1- -', 1- m , 2 7- ?. u - -. , "-.. ,- A- - -. --- 5 L., - . - . ~21~?-e cfO-2t . ,- . - -. - -iL- ." A %2 1 L~~~ :..- . -. 1- . ~OYY?S?O'?C:~.I? c . , -- - # ,. "- , T.*-. -, < - . - 7 -.., :+ I longitudinal shift 5, of the contact length may occur due to a driving or braking force. The influence of these shifts is felt - in the resulting aligning torque (aboif the vertical axis through the wheel center). These uniform carcass deformations will be held constant during each run of the element through the contact patch and-- updated at the end of each run. Only an,effective fraction of the carcass deflection (cc, ?)c may be taken into account due to the fact that the center of vertical pressure is not shifted over the same distance. ,- - _ - _ ^ . , __ -._"I. 4, - - 7- - Figure 1. Tread Element. Figurle 2. Coefficient of Friction. 5 Figure 3. The Rigid Carcass r rush-Type) Tire Model The center of the wheel has a speed V. Slip angle a indicates the angle between speed di.rection and (vertical) wheel center plane. We have a lateral speed, VY' which is equal to the lateral slip or creep speed, V : cY The longitudinal speed of the wheel center becomes: = cx v X v cos The wheel rotates about its axle (y-axis) with a speed -R Y . When under free rolling conditions and a=O the effective radius i.s denoted by Reo = V//nyol, we define the speed of rolling under general conditions: and the longitudinal slip speed: We introduce the two quantities which define the state of slip under straight line rolling, viz., the longitudinal slip sx and the lateral or side slip s Y: s Y = Vcy/Vx = tan a In general, also a turn slip due to a rotational speed QZ about the verticai z-axis will occur. Ir - l*".*i 1 The base point B of the tread element (Figs. 1,3) has speed components : v~~ = v CY + (x+ac)nz (8) I / I The sliding speed of the contact point (tip of element relative I to the road) is given by: I I For motions with relatively long wavelengths, the terms with QZ may be neglected. Henc:eforth we shall di-sregard the influence of the rotational speed artd use the equations: The tread element moves through the contact range with a speed equal to the rolling speed VT. The contact length is denoted by L = 2a and the time for one run through the contact patch becomes Note that the run time tends to infinity when the wheel is locked. This limits the analog simulation to sx values smaller than unity. As soon as the element has reached the end of the contact length (trailing edge) a new element is assumed to enter at the' leading edge. The i-th run starts at the instant ti-l and ends at + At. Coordinate x of the base of the element is determined by: The element has stif'fnesses kx and k and damping coeffi- " Y cients cx and c in x and y direction, respectively. At the tip Y of the element a concentra.ted mass, m, is considered to be present. The quantities kx and ky, cx and c and rn are taken per unit Y' length of circumference. TEe same holds for the shear force components qx and q and the vertical pressure distribution qZ.
Load more

Recommended publications
  • RELATIONSHIPS BETWEEN LANE CHANGE PERFORMANCE and OPEN- LOOP HANDLING METRICS Robert Powell Clemson University, [email protected]
    Clemson University TigerPrints All Theses Theses 1-1-2009 RELATIONSHIPS BETWEEN LANE CHANGE PERFORMANCE AND OPEN- LOOP HANDLING METRICS Robert Powell Clemson University, [email protected] Follow this and additional works at: http://tigerprints.clemson.edu/all_theses Part of the Engineering Mechanics Commons Please take our one minute survey! Recommended Citation Powell, Robert, "RELATIONSHIPS BETWEEN LANE CHANGE PERFORMANCE AND OPEN-LOOP HANDLING METRICS" (2009). All Theses. Paper 743. This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. RELATIONSHIPS BETWEEN LANE CHANGE PERFORMANCE AND OPEN-LOOP HANDLING METRICS A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Mechanical Engineering by Robert A. Powell December 2009 Accepted by: Dr. E. Harry Law, Committee Co-Chair Dr. Beshahwired Ayalew, Committee Co-Chair Dr. John Ziegert Abstract This work deals with the question of relating open-loop handling metrics to driver- in-the-loop performance (closed-loop). The goal is to allow manufacturers to reduce cost and time associated with vehicle handling development. A vehicle model was built in the CarSim environment using kinematics and compliance, geometrical, and flat track tire data. This model was then compared and validated to testing done at Michelin’s Laurens Proving Grounds using open-loop handling metrics. The open-loop tests conducted for model vali- dation were an understeer test and swept sine or random steer test.
    [Show full text]
  • TPMS Brochure
    SEE THE LIGHT? WE CAN HELP. Standard® OE-Matching TPMS Sensors, Mounting Hardware, Service Kits, Shop Tools, and QWIK-SENSOR™ Universal Programmable Sensors ABOUT TIRE PRESSURE MONITORING SYSTEMS The industry’s best blended TPMS program with 99% coverage. 2 Universal Sensors cover PAL, WAL, and Auto-Locate technologies. Our OE-Match sensors An Important Safety Warning Light Goes Unnoticed are direct-fit and ready-to-install right out of the During the past 10 years, more than 147 million vehicles were sold with Tire Pressure Monitoring System (TPMS). That means there box. And both programs are the only 3rd-party are more than 590 million sensors with a 100% failure rate that will need to be replaced in the future. TPMS is a safety device that tested TPMS in the industry. measures, identifies and warns motorists when one or more of their tires are significantly under-inflated. If the system finds a tire with low air pressure, a sensor with a dead battery, or a system malfunction, it will illuminate the TPMS warning light on the dash. While this is common knowledge to technicians, it isn’t as well-known among motorists, as evidenced by the results from a recent survey on TPMS: TPMS PROGRAM HIGHLIGHTS 96% 25% • Basic manufacturer in TPMS category Drivers who consider Vehicles that have at under-inflated tires an least one tire significantly - All makes & models – domestic and import covered important safety concern underinflated • Our OE-Matching and QWIK-SENSOR™ Universal Programs cover 99% of the vehicles you will service in your shop today
    [Show full text]
  • MF-Tyre/MF-Swift Copyright TNO, 2013
    MF-Tyre/MF-Swift Copyright TNO, 2013 MF-Tyre/MF-Swift Dr. Antoine Schmeitz 2 Copyright TNO, 2013 Dr. Antoine Schmeitz MF-Tyre/MF-Swift Introduction TNO’s tyre modelling toolchain tyre (virtual) testing parameter fitting + tyre model signal tyre MBS database MF-Tyre processing TYDEX files property solver file MF-Swift MF-Tool Measurement Identification Simulation Copyright TNO, 2013 1 MF-Tyre/MF-Swift 3 Copyright TNO, 2013 Dr. Antoine Schmeitz MF-Tyre/MF-Swift Introduction What is MF-Tyre/MF-Swift? MF-Tyre/MF-Swift is an all-encompassing tyre model for use in vehicle dynamics simulations This means: emphasis on an accurate representation of the generated (spindle) forces tyre model is relatively fast can handle continuously varying inputs model is robust for extreme inputs model the tyre as simple as possible, but not simpler for the intended vehicle dynamics applications 4 Copyright TNO, 2013 Dr. Antoine Schmeitz MF-Tyre/MF-Swift Introduction Model usage and intended range of application All kind of vehicle handling simulations: e.g. ISO tests like steady-state cornering, lane changes, J-turn, braking, etc. Sine with Dwell, mu split, low mu, rollover, fishhook, etc. Vehicle behaviour on uneven roads: ride comfort analyses durability load calculations (fatigue spectra and load cases) Simulations with control systems, e.g. ABS, ESP, etc. Analysis of drive line vibrations Analysis of (aircraft) shimmy vibrations; typically about 10-25 Hz Used for passenger car, truck, motorcycle and aircraft tyres Copyright TNO, 2013 2 MF-Tyre/MF-Swift 5 Copyright TNO, 2013 Dr. Antoine Schmeitz MF-Tyre/MF-Swift Modelling aspects and contents (1) 1.
    [Show full text]
  • Automotive Engineering II Lateral Vehicle Dynamics
    INSTITUT FÜR KRAFTFAHRWESEN AACHEN Univ.-Prof. Dr.-Ing. Henning Wallentowitz Henning Wallentowitz Automotive Engineering II Lateral Vehicle Dynamics Steering Axle Design Editor Prof. Dr.-Ing. Henning Wallentowitz InstitutFürKraftfahrwesen Aachen (ika) RWTH Aachen Steinbachstraße7,D-52074 Aachen - Germany Telephone (0241) 80-25 600 Fax (0241) 80 22-147 e-mail [email protected] internet htto://www.ika.rwth-aachen.de Editorial Staff Dipl.-Ing. Florian Fuhr Dipl.-Ing. Ingo Albers Telephone (0241) 80-25 646, 80-25 612 4th Edition, Aachen, February 2004 Printed by VervielfältigungsstellederHochschule Reproduction, photocopying and electronic processing or translation is prohibited c ika 5zb0499.cdr-pdf Contents 1 Contents 2 Lateral Dynamics (Driving Stability) .................................................................................4 2.1 Demands on Vehicle Behavior ...................................................................................4 2.2 Tires ...........................................................................................................................7 2.2.1 Demands on Tires ..................................................................................................7 2.2.2 Tire Design .............................................................................................................8 2.2.2.1 Bias Ply Tires.................................................................................................11 2.2.2.2 Radial Tires ...................................................................................................12
    [Show full text]
  • The World's Most Beautiful And... Best Performing Custom Designed Tires
    WelcomeWelcome ToTo TheThe World’sWorld’s MostMost BeautifulBeautiful and...and... BestBest PerformingPerforming CustomCustom DesignedDesigned TiresTires Bill Chapman Founder Diamond Back Classics I know what you are thinking! The tires on Bill’s Corvette are not correct. It’s not a show car-it is for my enjoyment. That’s the beauty of Diamond Back-you can get what’s period correct or you can get what you like. Custom whitewalls are not a problem. I offer many correct styles for the 60’s and 70’s cars or if you want something special, just let us know. My 2009 catalog features 16 product lines from 13” to 22” and anything in between. That’s more product than all the competitor’s combined. I’m also introducing two new top end product lines-the Diamond Back MX and the Diamond Back III. Both are built in North America by Michelin, the world’s most recognized tire manufacturer. If you’re going to spend over $200 per tire why not get the very best? Prices on the rest of my products will have a small increase and some will remain unchanged. Check out my warranty. It is the most solid, easy to understand warranty in the industry. My new extended warranty for $4.75 per tire is a smart move to protect your investment. As the year of the Great Recession begins, my goal remains unchanged-build the best looking, best performing product at a fair price. Thanks for all of your support! Confused and concerned about using radial tires on older rims? Get the facts ..
    [Show full text]
  • Estimation of Tire-Road Friction for Road Vehicles: a Time Delay Neural Network Approach
    Journal of the Brazilian Society of Mechanical Sciences and Engineering manuscript No. (will be inserted by the editor) Estimation of Tire-Road Friction for Road Vehicles: a Time Delay Neural Network Approach Alexandre M. Ribeiro · Alexandra Moutinho · Andr´eR. Fioravanti · Ely C. de Paiva Received: date / Accepted: date Abstract The performance of vehicle active safety sys- different road surfaces and driving maneuvers to verify tems is dependent on the friction force arising from the effectiveness of the proposed estimation method. the contact of tires and the road surface. Therefore, an The results are compared with a classical approach, a adequate knowledge of the tire-road friction coefficient model-based method modeled as a nonlinear regression. is of great importance to achieve a good performance Keywords Road friction estimation Artificial neural of different vehicle control systems. This paper deals · networks Recursive least squares Vehicle safety with the tire-road friction coefficient estimation prob- · · · Road vehicles lem through the knowledge of lateral tire force. A time delay neural network (TDNN) is adopted for the pro- posed estimation design. The TDNN aims at detecting 1 Introduction road friction coefficient under lateral force excitations avoiding the use of standard mathematical tire models, One of the primary challenges of vehicle control is that which may provide a more efficient method with robust the source of force generation is strongly limited by the results. Moreover, the approach is able to estimate the available friction between the tire tread elements and road friction at each wheel independently, instead of the road. In order to better understand vehicle handling using lumped axle models simplifications.
    [Show full text]
  • Chapter Trans 305
    Published under s. 35.93, Wis. Stats., by the Legislative Reference Bureau. 401 DEPARTMENT OF TRANSPORTATION Trans 305.02 Chapter Trans 305 STANDARDS FOR VEHICLE EQUIPMENT Subchapter I — General Provisions Trans 305.29 Steering and suspension. Trans 305.01 Purpose and scope. Trans 305.30 Tires and rims. Trans 305.02 Applicability. Trans 305.31 Modifications affecting height of a vehicle. Trans 305.03 Enforcement. Trans 305.32 Vent, side and rear windows. Trans 305.04 Penalty. Trans 305.33 Windshield defroster−defogger. Trans 305.05 Definitions. Trans 305.34 Windshields. Trans 305.06 Identification of vehicles. Trans 305.35 Windshield wipers. Trans 305.065 Homemade, replica, street modified, reconstructed and off−road vehicles. Subchapter III — Motorcycles Trans 305.37 Applicability of subch. II. Subchapter II — Automobiles, Motor Homes and Light Trucks Trans 305.38 Brakes. Trans 305.07 Definitions. Trans 305.39 Exhaust system. Trans 305.075 Auxiliary lamps. Trans 305.40 Fenders and bumpers. Trans 305.08 Back−up lamp. Trans 305.41 Fuel system. Trans 305.09 Direction signal lamps. Trans 305.42 Horn. Trans 305.10 Hazard warning lamps. Trans 305.43 Lighting. Trans 305.11 Headlamps. Trans 305.44 Mirrors. Trans 305.12 Parking lamps. Trans 305.45 Sidecars. Trans 305.13 Registration plate lamp. Trans 305.46 Suspension system. Trans 305.14 Side marker lamps, clearance lamps and reflectors. Trans 305.47 Tires, wheels and rims. Trans 305.15 Stop lamps. Trans 305.16 Tail lamps. Subchapter IV — Heavy Trucks, Trailers and Semitrailers Trans 305.17 Brakes. Trans 305.48 Definitions. Trans 305.18 Bumpers.
    [Show full text]
  • School Bus Tires Item and Method of Inspection Point
    SCHOOL BUS TIRES ITEM AND METHOD OF INSPECTION POINT VALUE AND REQUIREMENT DESCRIPTION (#) DESIGNATES POINTS TO BE DEDUCTED STANDARDS OF SAFETY AND REPAIR I. Tires: Visual Inspection of A. Front Tires (25)A.1. Recapped tires shall not 1. Recapped be used on front axle. 2. Tread Depth (Use a tread (25) 2. Front tire tread depth depth gauge) shall not be less than 4/32 inch in any two adja- a. See illustration tire cent major tread grooves wear measurement inform- at three equally spaced ation. Appendix A. intervals around the circumference of the tire. 3. Regrooved (25) 3. Any tire re-grooved or Re-cut below original groove depth when extra under-tread rubber was not provided for this purpose, or the tire is not marked "regroovable." 4. Condition = Visual (25) 4. a. Tire has unrepaired fabric defects of items a thru d break or was repaired by shall be cause for further use of a boot or blowout inspection of tire. patch. b. Tire has a bump, bulge, knot or separation. c. Tire has exposed or damaged body cords. 5. Size and Construction (25) 5. a. All tires on an axle a. Tires of a different must be of the same size size may be used, but and construction type not on the same axle. (bias ply or radial construction) tires must conform to the chassis manufacturer's gross vehicle weight rating. b. Tires of a different b. All tires on a bus must be size may not be used on of the same size and load bus after 12/31/94.
    [Show full text]
  • Final Report
    Final Report Reinventing the Wheel Formula SAE Student Chapter California Polytechnic State University, San Luis Obispo 2018 Patrick Kragen [email protected] Ahmed Shorab [email protected] Adam Menashe [email protected] Esther Unti [email protected] CONTENTS Introduction ................................................................................................................................ 1 Background – Tire Choice .......................................................................................................... 1 Tire Grip ................................................................................................................................. 1 Mass and Inertia ..................................................................................................................... 3 Transient Response ............................................................................................................... 4 Requirements – Tire Choice ....................................................................................................... 4 Performance ........................................................................................................................... 5 Cost ........................................................................................................................................ 5 Operating Temperature .......................................................................................................... 6 Tire Evaluation ..........................................................................................................................
    [Show full text]
  • Mechanical Analyses of Multi-Piece Mining Vehicle Wheels to Enhance Safety
    University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 2014 Mechanical Analyses of Multi-piece Mining Vehicle Wheels to Enhance Safety Zhanbiao Li University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Recommended Citation Li, Zhanbiao, "Mechanical Analyses of Multi-piece Mining Vehicle Wheels to Enhance Safety" (2014). Electronic Theses and Dissertations. 5197. https://scholar.uwindsor.ca/etd/5197 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder (original author), cannot be used for any commercial purposes, and may not be altered. Any other use would require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or thesis from this database. For additional inquiries, please contact the repository administrator via email ([email protected]) or by telephone at 519-253-3000ext. 3208. Mechanical Analyses of Multi-piece Mining Vehicle Wheels to Enhance Safety By Zhanbiao Li A Dissertation Submitted to the Faculty of Graduate Studies through Mechanical, Automotive, and Materials Engineering Department in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the University of Windsor Windsor, Ontario, Canada 2014 © 2014 Zhanbiao Li Mechanical Analyses of Multi-piece Mining Vehicle Wheels to Enhance Safety By Zhanbiao Li APPROVED BY: __________________________________________________ Dr.
    [Show full text]
  • Nonlinear Finite Element Modeling and Analysis of a Truck Tire
    The Pennsylvania State University The Graduate School Intercollege Graduate Program in Materials NONLINEAR FINITE ELEMENT MODELING AND ANALYSIS OF A TRUCK TIRE A Thesis in Materials by Seokyong Chae © 2006 Seokyong Chae Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2006 The thesis of Seokyong Chae was reviewed and approved* by the following: Moustafa El-Gindy Senior Research Associate, Applied Research Laboratory Thesis Co-Advisor Co-Chair of Committee James P. Runt Professor of Materials Science and Engineering Thesis Co-Advisor Co-Chair of Committee Co-Chair of the Intercollege Graduate Program in Materials Charles E. Bakis Professor of Engineering Science and Mechanics Ashok D. Belegundu Professor of Mechanical Engineering *Signatures are on file in the Graduate School. iii ABSTRACT For an efficient full vehicle model simulation, a multi-body system (MBS) simulation is frequently adopted. By conducting the MBS simulations, the dynamic and steady-state responses of the sprung mass can be shortly predicted when the vehicle runs on an irregular road surface such as step curb or pothole. A multi-body vehicle model consists of a sprung mass, simplified tire models, and suspension system to connect them. For the simplified tire model, a rigid ring tire model is mostly used due to its efficiency. The rigid ring tire model consists of a rigid ring representing the tread and the belt, elastic sidewalls, and rigid rim. Several in-plane and out-of-plane parameters need to be determined through tire tests to represent a real pneumatic tire. Physical tire tests are costly and difficult in operations.
    [Show full text]
  • Study on the Stability Control of Vehicle Tire Blowout Based on Run-Flat Tire
    Article Study on the Stability Control of Vehicle Tire Blowout Based on Run-Flat Tire Xingyu Wang 1 , Liguo Zang 1,*, Zhi Wang 1, Fen Lin 2 and Zhendong Zhao 1 1 Nanjing Institute of Technology, School of Automobile and Rail Transportation, Nanjing 211167, China; [email protected] (X.W.); [email protected] (Z.W.); [email protected] (Z.Z.) 2 College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; fl[email protected] * Correspondence: [email protected] Abstract: In order to study the stability of a vehicle with inserts supporting run-flat tires after blowout, a run-flat tire model suitable for the conditions of a blowout tire was established. The unsteady nonlinear tire foundation model was constructed using Simulink, and the model was modified according to the discrete curve of tire mechanical properties under steady conditions. The improved tire blowout model was imported into the Carsim vehicle model to complete the construction of the co-simulation platform. CarSim was used to simulate the tire blowout of front and rear wheels under straight driving condition, and the control strategy of differential braking was adopted. The results show that the improved run-flat tire model can be applied to tire blowout simulation, and the performance of inserts supporting run-flat tires is superior to that of normal tires after tire blowout. This study has reference significance for run-flat tire performance optimization. Keywords: run-flat tire; tire blowout; nonlinear; modified model Citation: Wang, X.; Zang, L.; Wang, Z.; Lin, F.; Zhao, Z.
    [Show full text]