1、 _ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising ther
2、efrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this
3、publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-49
4、70 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2429_201509 SURFACE VEHICLE INSERT DOCUMENT TYPE J2429 SEP2015 Issued 1998-01 R
5、evised 2015-09 Superseding J2429 MAY2004 Free-Rolling Cornering Test for Truck and Bus Tires RATIONALE The original document made some assumptions regarding future work that have not been met. Additionally, the over-the-road test machine mentioned in the text has been decommissioned and is no longer
6、 available. Needs for corrections were found during the renewal process. The purpose of this revision is to implement these corrections and bring the document up to date in light of developments between 2004 and 2015. 1. SCOPE This SAE Recommended Practice describes a test method for determination o
7、f heavy truck (Class VI, VII, and VIII) tire force and moment properties under free-rolling cornering conditions. The steady-state properties are acquired as functions of slip angle and normal force, which are changed incrementally using a sequence specified in this document. The data are suitable f
8、or use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control. This document addresses two principal topics; a) the description of a hypothetical “Ideal Machine,” and b) a standard directly applicable to testing practices curren
9、tly common to the industry. The references to the “Ideal Machine” are meant to provide a roadmap for the testing machine manufacturer, providing direction and goals for the next generation of testing capabilities. The ranges of parameters for the “Ideal Machine,” including those in Tables 2 and 3, a
10、re intended to represent minimal requirements to meet the full and complete data needs of the industry. The remaining documentation provides practical guidelines for the test engineer to ensure the integrity of data generated using current and conventional means. 1.1 Truck Tires For the purposes of
11、this document, truck tires are defined as being the tires mounted on all heavy commercial over-the-road trucks and buses. Examples of vehicles which use heavy truck tires include: tractor/semi-trailer combinations, dump trucks, school buses, etc. Tires mounted on other types of lighter GVWR vehicles
12、 are explicitly excluded from consideration in this document. 1.2 Effects Not Considered The effects of inclination angle and spindle torque or any combination of inclination angle or spindle torque with slip angle and / or normal force are not considered in this document. SAE INTERNATIONAL J2429 SE
13、P2015 Page 2 of 24 1.3 Test Machines This document is test machine neutral. It may be applied using any type of test machine capable of fulfilling the requirements stated in this document. By way of example, specific data used in support of various parts of this document came from both an indoor fla
14、t-belt type machine, the CALSPAN Tire Research Facility (TIRF), and an outdoor over-the-road dynamometer, the University of Michigan Transportation Research Institute (UMTRI) Mobile Tire Dynamometer. This document does not require a machine to match the ideal machine defined in Section 1.3.1, but do
15、es require that a test machines performance be fully defined over its range of application. In this document, an ideal is a goal not a requirement. NOTE: The UMTRI Mobile Tire Dynamometer was decommissioned and is no longer available in response to an institute decision to no longer engage in testin
16、g. It is still mentioned in this revision because much of the supporting data was taken with the UMTRI machine and experience with it shows the quality of information that can be obtained with a machine of this type. 1.3.1 Ideal Machine This document references an ideal machine which is capable of f
17、ully matching every item in this document, as well as those found in documents SAE J2673 and SAE J2675, to the extent specified herein. Such a machine neither existed at the time this document was written nor is it certain that the technology to build such a machine exists at this time. However, it
18、is important to establish the parameters that define an ideal machine, so that as testing capabilities evolve, they do so with specific goals in mind. The ideal machine is defined without regard to the configuration of the machine or current capabilities it is defined instead by its ability to provi
19、de desired levels of quality, accuracy, repeatability, and range of data. Current limits of available technology bound the feasible performance of any type of machine to somewhat different levels. However, while the existence of an “ideal machine” would overcome these limits in performance, this rec
20、ommended procedure does not depend on having an ideal machine. Useful data can be, and has been, gathered on existing machines for years. However, for repeatability, and for situations when data from different machines might be compared, it is important to document the capability of each machine tha
21、t contributes data. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwea
22、lth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. SAE J670 Vehicle Dynamics Terminology SAE J2047 Tire Performance Terminology SAE J2673 Straight-Line Braking Test for Truck and Bus Tires SAE J2675 Combined Cornering and Br
23、aking Test for Truck and Bus Tires SAE 760029 Effects of Test Speed and Surface Curvature on Cornering Properties of Tires, M. G. Pottinger, K. D. Marshall, and G. A. Arnold, 1976. SAE 770870 The Effect of Tire Break-In on Force and Moment Properties, K. D. Marshall, R. L. Phelps, M. G. Pottinger, a
24、nd W. Pelz, 1977. SAE 810066 The Effect of Aging on Force and Moment Properties of Radial Tires, M. G. Pottinger and K. D. Marshall, 1981. SAE 960180 A Model for Combined Cornering and Braking Forces, D. J. Schuring, W. PelzM. G. Pottinger, 1996. SAE INTERNATIONAL J2429 SEP2015 Page 3 of 24 SAE 9621
25、53 Truck Tire Wet Traction: Effects of Water Depth, Speed, Tread Depth, Inflation, and Load, M. G. Pottinger, W. Pelz, D. M. Pottinger, and C. B. Winkler, 1996. SAE CRP-11 Truck Tire Characterization, December 1995 NOTE: CRP-11 is a book compiling the results of a very long and involved research stu
26、dy. It is indexed by the original statement of work (SOW) element numbers. Contained within CRP-11 are these elements relevant to this J-Document: Final Report (SOW 1.2.1), M. G. Pottinger, August 7, 1994. Recommended Test Sample Sizes (SOW 1.5) and the CALSPAN/UMTRI Comparison (SOW 3.0), M. G. Pott
27、inger and W. Pelz, July 30, 1994. 2.1.2 Tire and Rim Association Publications Available from the Tire and Rim Association, 175 Montrose West Avenue, Suite 150, Copley, OH 44321-2793, Tel: 330-666-8121, www.us-tra.org. XXXX Year Book, The Tire and Rim Association, Inc. (XXXX stands for the current ye
28、ar) 2.2 Related Publications The following publications are provided for information purposes only and are not a required part of this SAE Technical Report. OSHA Standard 1910.77Available in wall chart form as #TTMP-7/95 from the Rubber Manufacturers Association, 1400 K St., NW Suite 900, Washington
29、, DC 20005. Tel: 202-682-4800, www.rma.org. NIST Handbook 105 Specifications and Tolerances for Reference Standards and Field Standard Weights and Measures (NIST Class F) Available electronically at http:/ts.nist.gov/ts/htdocs/230/235/105-1.pdf. Paper #45 American Chemical Society Mtg., October 17,
30、1995, Straight-Line Braking Test for Heavy Duty Truck Tires, M.G. Pottinger, G.A. Tapia, C.B. Winkler and W. Pelz. 3. DEFINITIONS The definitions, which follow, are of special meaning in this document and are either not contained in other documents or are worded somewhat differently in this document
31、. NOTE: Definitions and symbols in this document employ the SAE J670 Superseded Tire Axis System (called the Historic SAE Tire Axis System in SAE J2047), which is described in Appendix C of SAE J670. 3.1 TEST Execution of the procedure described in this document one time on one tire. 3.2 TEST PROGRA
32、M A test program, as referred to in this document, is a designed experiment involving a set of the tests described in this document. 4. NOMENCLATURE Table 1 lists the symbols used in this document. SAE INTERNATIONAL J2429 SEP2015 Page 4 of 24 Table 1 - Symbols defined Symbol Defined Term Slip Angle
33、C Force and Moment Interaction Matrix FACT Force and Moment Corrected for Interactions FSEN Force and Moment Sensed by Measuring System Fcal Forces and Moments Applied During Calibration FX FY Longitudinal Force Lateral Force FZ Normal Force Inclination Angle MX Overturning Moment MZ Aligning Moment
34、 Spin Angular Velocity about the Wheel Spindle p Inflation Pressure R1 Loaded Radius S Test Speed SR Slip Ratio TA Ambient Temperature TS Spindle Torque 5. APPARATUS 5.1 Conventional Laboratory Machines A conventional laboratory machine for performing truck tire force and moment testing according to
35、 this document is comprised of three systems: a simulated roadway whose surface moves at the test speed, a loading and positioning system, and a measuring system. Table 2 specifies the applicable setting accuracies with respect to test speed, loading, and positioning plus ideal control setting rates
36、 for machines capable of performing not only this test, but also, other related tests such as straight-line braking and combined cornering and braking. NOTE: Torque control is not addressed in Table 2 because the J2673 and J2675 tests only involve slip ratio ramping and torque control is difficult f
37、or slip ratio magnitudes equal to or greater than those associated with peak friction. Further, torque control places a requirement on the system that torque be generated by a motor system. SAE INTERNATIONAL J2429 SEP2015 Page 5 of 24 Table 2 - Laboratory machine control setting accuracies and rates
38、 Setting Least Acceptable Setting Accuracy SI Units Least Acceptable Setting Accuracy USC Units Test Speed 1.0 km/h 0.6 mph Normal Force 1% of Full Scale 1% of Full Scale Slip Angle 0.05 degree 0.05 degree Inclination Angle(1)0.05 degree 0.05 degree Spin Angular Velocity(1)10rpm 10rpm Rate Ideal Max
39、imum Rate Normal Force 8900 N/s 2000 lb/s Slip Angle 5 degrees/s 5 degrees/s Spin Angular Velocity(1)1200 rpm/s 1200 rpm/s Inclination Angle(1) 1 degree/s 1 degree/s .1 Inclination Angle () and spin angular velocity () are not required and are not used in this document. They are provided should anyo
40、ne desire to build a machine for more general tests. 5.1.1 Simulated Roadway The simulated roadway shall be a surface coated with an abrasive material. The abrasive material shall exhibit essentially stable frictional properties over a useful period of time as confirmed by a control tire testing pro
41、cedure such as the example included in Section 7, Preparation of Apparatus. The roadway shall be maintained free of loose materials and deposits. NOTE: The proper frictional characteristics for the simulated road surface and the change of the frictional characteristics with time (surface endurance)
42、are not defined. These are subjects which should be resolved through research. 5.1.1.1 The roadway shall be wide enough to support the entire test tire footprint. Ideally, the active width would be 800 mm (31.5 in) to insure that the widest standardized or currently envisioned tire (e.g. 605/70R20.5
43、, 24R20.5, etc.) could be tested. 5.1.1.2 The roadway and its supporting structure shall be sufficiently rigid so as to not change appreciably in either transverse or longitudinal curvature or angular orientation under the maximum test loads and/or slip angles applied in this document. 5.1.1.3 The r
44、oadway shall preferably be flat or, if curved, have a very large radius (radius 1.52 m, or 60.0 in), as roadway curvature distorts tire force and moment properties (SAE 760029). Though combined cornering and braking data to support this requirement do not currently exist, the probable correctness of
45、 this requirement can be inferred from the distortion of free-rolling force and moment properties induced by roadway curvature (SAE 760029), which implies the need for an impractically large round wheel machine to provide data indistinguishable from flat surface data. 5.1.1.4 The drive system shall
46、be capable of operating the roadway at the test speed, S. An ideal drive system would permit speeds between 10 and 120 km/h (6 and 75 mph). Test speed affects tire force and moment data (SAE 760029) and tire force and moment data in braking (SAE 962153). Therefore, it is desirable to specify test sp
47、eed, S, as realistically as possible consistent with the test machines capabilities. 5.1.1.5 Ambient temperature, TA, shall be maintained within the allowable range specified in Sections 8 and 9. Ambient temperature affects tire temperature and tire temperature affects tire force and moment data (SA
48、E 770870). SAE INTERNATIONAL J2429 SEP2015 Page 6 of 24 5.1.2 Loading and Positioning System The system positions the tire with respect to the roadway and loads it against the roadway surface at the normal force, Fz, specified in Section 9. The system shall accommodate the tire sizes to be tested. 5
49、.1.2.1 The loading and positioning system shall accommodate tire-wheel-assemblies with diameters and widths required by users. An ideal system would accommodate rims from 15X6.00 to 24.5X16 allowing testing of tires between 800 mm and 1400 mm (31.5 to 55.0 in) in outside diameter with section widths up to 645 mm (25.4 in). 5.1.2.2 The loading mechanism shall be able to exert the normal forces requi
