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 theref
2、rom, 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 2014 SAE InternationalAll rights reserved. No part of this publi
3、cation 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/J2673_201406SURFACE VEHICLERECOMMENDED PRACTICEJ2673 JUN2014Issued 2004-05Revised 2014-06Supe
5、rseding J2673 MAY2004Straight-Line Braking Test for Truck and Bus TiresRATIONALEThe 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 available. Other requi
6、red revisions were found during the renewal process. The purpose of these revisions is to incorporate the most correct practices and bring the document up to date in light of developments between 2004 and 2014.1. SCOPEThis SAE Recommended Practice describes a test method for determination of heavy t
7、ruck (Class VI, VII, and VIII) tire force and moment properties under straight-line braking conditions. The properties are acquired as functions of normal force and slip ratio using a sequence specified in this practice. At each normal force increment, the slip ratio is continually changed by applic
8、ation of a braking torque ramp. The data are suitable for use in vehicle dynamics modeling, comparative evaluations for research and development purposes, and manufacturing quality control.1.1 Truck TiresFor the purposes of this document, truck tires are defined as being the tires mounted on all hea
9、vy 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 are explicitly excluded from consideration in this document.1.2 Control Mo
10、des and Effects Not ConsideredThe effects of non-zero inclination angle and non-zero slip angle or any combination of non-zero inclination angle, non-zero slip angle, and spindle torque with normal force are not considered. 1.3 Test MachinesThis document is test machine neutral. It may be applied us
11、ing any type of test machine capable of fulfilling therequirements stated in this document. By way of example, specific data used in support of various parts of this document came from both an indoor flat-belt type machine, CALSPAN TIRF, and outdoor over-the-road dynamometer, UMTRI Mobile Tire Dynam
12、ometer. This document does not require a machine to match the ideal machine, but does 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.SAE INTERNATIONAL J2673 Revised JUN2014 Page 2 of 22NOTE: The UMTRI Mo
13、bile Tire Dynamometer was decommissioned and is no longer available in response to an institute decision to no longer engage in testing. It is still mentioned in this revision because much of the backup data for SAE J2675 was taken with the UMTRI machine and experience with it shows the quality of i
14、nformation that can be obtained with a machine of this type.1.3.1 Ideal MachineThis document references an ideal machine which is capable of fully matching every item in this document, SAE J2429, and SAE J2675. Such a machine neither existed at the time this document was written nor is it certain th
15、at the technology to build such a machine exists at this time. However, this recommended procedure does not depend on having an ideal machine. Useful data can be, and has been gathered on existing machines. However, for repeatability and for situations when data from different machines might be comp
16、ared, it is important to document the capability of each machine that contributes data.2. REFERENCES2.1 Applicable DocumentsThe following publications form a part of the specification to the extent specified herein. Unless otherwise indicated the latest revision of SAE publications shall apply.2.1.1
17、 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.CRP-11 Truck Tire Characterization, December, 1995NOTE: CRP-11 is a book compiling the results of a very long and
18、 involved research study. It is indexed by the original statement of work (SOW) element numbers.Contained within CRP-11 are:SOW 1.2.2 Final Report, M. G. Pottinger, September 20, 1994.Straight-Line Braking Test for Heavy Duty Truck tires, M. G. Pottinger, G. A. Tapia, C. B. Winkler, W. Pelz, ACS Mtg
19、., 10/17-19/1995.Recommended Test Sample Sizes (SOW 1.5) and The CALSPAN/UMTRI Comparison (SOW 3.0) for SOW1.2.2 Data, SAE CRP-11, M. G. Pottinger, W. Pelz, September 9, 1994.SAE J670 Vehicle Dynamics TerminologySAE J2047 Tire Performance TerminologySAE J2429 Free-Rolling Cornering Test for Truck an
20、d Bus TiresSAE J2675 Combined Cornering and Braking Test for Truck and Bus TiresSAE 760029 Effects of Test Speed and Curvature on Cornering Properties of Tires, M. G. Pottinger, K. D. Marshall, and G. A. Arnold, 1976.SAE 962153 Truck Tire Wet Traction: Effects of Water Depth, Speed, Tread Depth, Inf
21、lation, and Load, M. G. Pottinger, W. Pelz, D. M. Pottinger, and C. B. Winkler, 1996.SAE 770870 The Effect of Tire Break-in on Force and Moment Properties, K. D. Marshall, R. L. Phelps, M. G. Pottinger, and W. Pelz, 1977.SAE 810066 The Effect on Aging on Force and Moment Properties of Radial tires,
22、M. G. Pottinger and K. D. MarshallSAE INTERNATIONAL J2673 Revised JUN2014 Page 3 of 22SAE 962153 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. Winkler2.1.2 Tire and Rim Association PublicationsAvailable
23、from the Tire and Rim Association, Inc., 175 Montrose West Avenue, Suite 150, Copley, OH 44321-2793, Tel: 330-666-8121, www.us-tra.org.XXXX Yearbook, The Tire and Rim Association, Inc. (XXXX stands for the current year)2.1.3 European Tyre and Rim Technical Organisation, Publications available from t
24、he European Tyre and Rim Technical Organisation, 78/80, rue Defacqz B-1060 Brussels, Belgium, Tel: 32-3-344-40-59, www.etrto.org2.2 Related PublicationsThe following publications are provided for information purposes only and are not a required part of this SAE Technical Report.OSHA Standard 1910.77
25、 Available in wall chart form as #TTMP-7/95 from the Rubber Manufacturers Association, 1400 K St., N.W., Washington, DC 20005.NIST Handbook 105-1 Specifications and Tolerances for Reference Standards and Field Standard Weights andMeasures (NIST Class F) Available electronically at http:/ts.nist.gov/
26、ts/htdocs/230/235/105-1.pdf.Paper #45, American Chemical Society Mtg., October 17, 1995, Straight-Line Braking Test for Heavy Duty Truck Tires, M.G. Pottinger, G.A. Tapia, C.B. Winkler and W. Pelz.3. DEFINITIONSThe definitions, which follow, are of special meaning in this document and are either not
27、 contained in other documents or are worded somewhat differently in this document.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 TESTExecution of
28、the procedure described in this document one time on one tire.3.2 TEST PROGRAMA designed experiment involving a set of the tests described in this document.SAE INTERNATIONAL J2673 Revised JUN2014 Page 4 of 224. NOMENCLATURETable 1 lists the symbols used in this document.TABLE 1 - SYMBOLS DEFINEDSymb
29、ol Defined TermD Slip AngleC Force and Moment Interaction MatrixFACTForce and Moment Corrected for InteractionsFSENForce and Moment Sensed by Measuring SystemFcal Forces and Moments Applied During CalibrationFXLongitudinal ForceFYLateral ForceFZNormal ForceJ Inclination AngleMXOverturning MomentMZAl
30、igning MomentZ Spin Angular Velocity About the Wheel Spindlep Inflation PressureR1Loaded RadiusS Test SpeedSR Slip RatioTAAmbient TemperatureTSSpindle Torque5. APPARATUS5.1 Laboratory MachinesA laboratory machine for performing truck tire force and moment testing according to this document is compri
31、sed of three systems: a simulated roadway, 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 for machines capable of performing not only this test, but al
32、so, other related tests such as free-rolling cornering and combined cornering and braking. NOTE: Torque control is not addressed in Table 2 because the test only involves slip ratio ramping and torque control is only practical for slip ratio magnitudes less than that associated with peak friction. F
33、urther, torque control places a requirement on the system that torque be generated by a motor system.SAE INTERNATIONAL J2673 Revised JUN2014 Page 5 of 22TABLE 2 - LABORATORY MACHINE CONTROL SETTINGACCURACIES AND IDEAL RATESSettingLeast AcceptableSetting AccuracySI UnitsLeast AcceptableSetting Accura
34、cyUSC UnitsTest Speed 1.0 km/h 0.6 mphNormal Force 1% of Full Scale 1% of Full ScaleSlip Angle10.05 degree 0.05 degreeInclination Angle10.05 degree 0.05 degreeSpin Angular Velocity210 rpm 10 rpmRate Ideal Maximum RateNormal Force t 8900 N/s t 2000 lb/sSlip Angle t 5 degrees/s t 5 degrees/sSpin Angul
35、ar Velocity t 1200 rpm/s t 1200 rpm/sInclination Angle1t 1 degree/s t 1 degree/s1Slip Angle (D) and Inclination Angle (J) are not required and are not used in this document. They are provided should anyone desire to build a machine for more general tests.2Precise control of Spin Angular Velocity (Z)
36、 would only be possible in the case of an Ideal Machine using a motor to apply torque to the test tire. It is not necessary to set a given steady-state Z level within the test discussed in this Recommended Practice. In the case of this practice it is only necessary that the machine generate a brakin
37、g ramp that sweeps through the required Slip Ratio (SR) range defined in Section 9, Test Procedure, within the specified test time.5.1.1 Simulated RoadwayThe simulated roadway shall be a surface coated with an abrasive material. The abrasive material shall exhibit essentially stable frictional prope
38、rties over a useful period of time as confirmed by a control tire testing procedure 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
39、 the change of the frictional characteristicswith time (surface endurance) are not defined. These are subjects that should be resolved through research prior to the 5-year renewal of this document.5.1.1.1 The roadway shall be wide enough to support the entire tire footprint. Ideally, the active widt
40、h would be 800 mm (31.5 in) to insure that the widest envisioned tire (605/70R20.5, 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
41、the maximum test loads applied in this document.5.1.1.3 The roadway shall be flat. Though straight-line braking data to support this requirement does not exist, the probable correctness of this requirement can be inferred from the distortion of free-rolling force and moment properties by roadway cur
42、vature (SAE 760029). It is certainly correct for a general-purpose machine.5.1.1.4 The drive system shall be capable of operating the roadway at the test speed, S. An ideal drive system wouldpermit speeds between 10 and 120 km/h (6 and 75 mph). Test speed affects tire force and moment data in brakin
43、g (SAE 962153). Therefore, it is desirable to specify test speed, S, as realistically as possible consistent with the test machines capabilities.5.1.1.5 Temperature shall be maintained within the allowable ambient temperature, TA, range specified in Section 8, Selection and Preparation of Test Tires
44、, and Section 9, Test Procedure. Ambient temperature affects tire temperature and tire temperature affects tire force and moment data (SAE 770870).SAE INTERNATIONAL J2673 Revised JUN2014 Page 6 of 225.1.2 Loading and Positioning SystemThe system positions the tire with respect to the roadway and loa
45、ds it against the roadway surface at the normal forces, Fz, specified in Section 9 of this document, Test Procedure. The system shall accommodate the tire sizes to be tested.5.1.2.1 The loading and positioning system shall accommodate tire-wheel-assemblies with diameters and widths required by users
46、. 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 (25.4in).5.1.2.2 The loading mechanism shall be able to exert the normal forces required by the Test Procedure,
47、 Section 9, for the tire to be tested. An ideal loading system would be able to exert normal force magnitudes of up to 140 kN (31 500 lb).5.1.2.3 For this test, the positioning system and its supporting structure shall provide a slip angle of D = 0 0.05. If setting capability is provided for slip an
48、gle, as part of a general machine, the positioning system and its supporting structure shall, as a minimum, permit incremental setting of slip angles from 7 degrees to +7 degrees. An ideal slip angle setting system would be able to continuously set slip angles from 15 degrees to +15 degrees at a min
49、imum.5.1.2.4 For this test, the positioning system and its supporting structure shall provide an inclination angle of J =0qr0.05. If setting capability is provided for inclination angle, as part of a general machine, the positioning system and its supporting structure shall, as a minimum, permit incremental setting of inclination angles from 5degrees to +5 degrees. An ideal inclination an
