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 2017 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:/standards.sae.org/J2675_201711 SURFACE VEHICLE RECOMMENDED PRACTICE J2675 NOV2017 Issued 2004-04 Revised 2017-11
5、 Superseding J2675 OCT2010 Combined Cornering and Braking Test for Truck and Bus Tires RATIONALE The purpose of this revision is to correct minor errors in the existing document and to bring the document up to date in light of developments between 2010 and 2017. The original document referenced an o
6、ver-the-road test machine that has since been decommissioned and is no longer available. The document has also been updated to include a new class of hybrid testing machines which test a tire while moving it over a paved surface in a controlled environment. 1. SCOPE This SAE Recommended Practice des
7、cribes a test method for determination of heavy truck (Class VI, VII, and VIII) tire force and moment properties under combined cornering and braking conditions. The properties are acquired as functions of slip angle, normal force, and slip ratio. Slip angle and normal force are changed incrementall
8、y using a sequence specified in this document. At each increment, the slip ratio is continually changed by application 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 contro
9、l. This document is intended to be a general guideline for testing on an ideal machine, and modifications to the protocols recommended within are expected depending on the requirements of each customer. Due care is necessary when modifying protocols to ensure that the integrity of the data is mainta
10、ined. 1.1 Truck Tires For the purposes of this document, truck tires are defined as being the tires mounted on all heavy commercial over-the-road trucks (Class VI, VII, and VIII) and buses. Examples of vehicles which use heavy truck tires include tractor/semi-trailer combinations, dump trucks, and s
11、chool buses. Tires mounted on classes of commercial vehicles other than Classes VI, VII, or VIII, and other types of lighter GVWR vehicles, are explicitly excluded from consideration in this document. 1.2 Effects Not Considered The effects of non-zero inclination angle or any combination of non-zero
12、 inclination with non-zero slip angle, non-zero torque, and normal force are not considered in this document, but the accuracies of machines including inclination are referenced. SAE INTERNATIONAL J2675 NOV2017 Page 2 of 27 1.3 Test Machines This document is test machine neutral. It may be applied u
13、sing 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 flat-belt type machine, the CALSPAN Tire Research Facility (TIRF) (as it stood in 2004), and an ou
14、tdoor 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 1.3.1, but does require that a test machines performance be fully defined over its range of ap
15、plication. Note: 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 testing. It is still mentioned in this revision because much of the backup data f
16、or SAE J2675 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 fully matching every item in this document, SAE J2429, and SAE J26
17、73. Such a machine neither exists currently nor is it certain that the technology to build such a machine exists. 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 situat
18、ions when data from different machines might be compared, it is important to document the capability of each machine that 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,
19、the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. SAE CRP-11 Truck Tire Characterization, December 1995
20、 NOTE: CRP-11 is a book compiling the results of a very long and involved research study. It is indexed by the original statement of work (SOW) element numbers. Contained within CRP-11 are: M. G. Pottinger, W. Pelz, G. A. Tapia, and C. B. Winkler, “A Combined Cornering and Braking Test for Heavy Dut
21、y Truck Tires,” 4th International Symposium on Heavy Vehicle Weights and Dimensions, University of Michigan, Ann Arbor, MI, June 25-29, 1995, pp. 583-592. M. G. Pottinger, and W. Pelz, “Recommended Test Sample Sizes (SOW 1.5) and The CALSPAN/UMTRI Sample Sizes (SOW 1.5) and The CALSPAN/UMTRI Compari
22、son (SOW 3.0) for SOW 1.2.3 Data,” Smithers Scientific Services, Inc., April 12, 1995. SAE J670 Vehicle Dynamics Terminology SAE J2047 Tire Performance Technology SAE J2429 Free-Rolling Cornering Test for Truck and Bus Tires SAE J2673 Straight-Line Braking Test for Truck and Bus Tires SAE INTERNATIO
23、NAL J2675 NOV2017 Page 3 of 27 SAE 760029 Pottinger, M.G., Marshall, K.D., and Arnold, G.A., “Effects of Test Speed and Surface Curvature on Cornering Properties of Tires,“ SAE Technical Paper 760029, 1976, doi:10.4271/760029. SAE 770870 Marshall, K.D., Phelps, R.L., Pottinger, M.G., and Pelz, W., “
24、The Effect of Tire Break-In on Force and Moment Properties,“ SAE Technical Paper 770870, 1977, doi:10.4271/770870. SAE 810066 Pottinger, M.G. and Marshall, K.D., “The Effect of Tire Aging on Force and Moment Properties of Radial Tires,“ SAE Technical Paper 810066, 1981, doi:10.4271/810066. SAE 96018
25、0 Schuring, D.J., Pelz, W., and Pottinger, M.G., “A Model for Combined Cornering and Braking Forces,“ SAE Technical Paper 960180, 1996, doi:10.4271/960180. SAE 962153 Pottinger, M.G., Pelz, W., Pottinger, D.M., and Winkler, C.B., “Truck Tire Wet Traction: Effects of Water Depth, Speed, Tread Depth,
26、Inflation, and Load,“ SAE Technical Paper 962153, 1996, doi:10.4271/962153. 2.1.2 Tire and Rim Association Publications Available from The Tire and Rim Association, Inc., 175 Montrose West Avenue, Suite 150, Copley, OH 44321, Tel: 330-666-8121, www.us-tra.org . XXXX Yearbook, The Tire and Rim Associ
27、ation, Inc. (XXXX stands for the current year) 2.2 Other Publications OSHA Standard 1910.77 Available in wall chart form as #TTMP-7/95 from the Rubber Manufacturers Association, 1400 K St., NW, Suite 900, Washington, DC 20005, Tel: 202-682-4800, www.rma.org. NIST Handbook 105-1 Specifications and To
28、lerances 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. 3. DEFINITIONS The definitions, which follow, are of special meaning in this document and are either not contained in other documents or
29、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_201303), which is described in appendix C of SAE J670_200801. 3.1 TEST Execution of the procedure de
30、scribed in this document one time on one tire. 3.2 TEST PROGRAM A test program 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 J2675 NOV2017 Page 4 of 27 Table 1 - Symbols defined Sym
31、bol Defined Term Slip Angle C Force and Moment Interaction Matrix FACT Force and Moment Corrected for Interactions FCAL Forces and Moments Applied During Calibration FSEN Force and Moment Sensed by Measuring System FX Longitudinal Force FY Lateral Force FZ Normal Force Inclination Angle m meter MX O
32、verturning Moment MZ Aligning Moment 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 f
33、orce and moment testing according to this document is comprised 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. Table 2 also specifies ideal cont
34、rol setting rates for machines capable of performing not only this test, but also other related tests such as free-rolling cornering and straight-line braking. NOTE: Torque control is not addressed in Table 2 because the test only involves slip ratio ramping; torque control is only practical for sli
35、p ratio magnitudes less 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 J2675 NOV2017 Page 5 of 27 Table 2 - Laboratory machine control setting accuracies and ideal rates Largest Accept
36、able Tolerance and Rates For Setting Accuracy SI Units USC Units Setting Tolerance Ideal Max Rate Tolerance Ideal Max Rate Test Speed 1.0 km/h 0.6 mph Normal Force 1% of Full Scale 8900 N/s 1% of Full Scale 2000 lb/s Slip Angle 0.05 5 degrees/s 0.05 5 degrees/s Inclination Angle(1) 0.05 1 degree/s 0
37、.05 1 degree/s Spin Angular Velocity(2) 10 rpm 1200 rpm/s 10 rpm 1200 rpm/s 1. Inclination Angle () is not required and is not used in this document. It is provided should anyone desire to build a machine for more general tests. 2. Precise control of Spin Angular Velocity () would only be possible i
38、n 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 level within the test discussed in this Recommended Practice. In the case of this practice it is only necessary that the machine generate a braking ramp that sweeps through
39、the required Slip Ratio (SR) range defined in Section 9 within the specified test time. 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 conf
40、irmed by a control tire testing procedure such as the example included in Section 7. 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 en
41、durance) 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 tire footprint. Ideally, the active width would be 800 mm (31.5 in) to ensure that the widest standardized or currently envisioned tire (e.g., 605/70
42、R20.5, 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 the maximum test loads, torques, and slip angles applied in this document. 5
43、.1.1.3 The roadway shall be flat. Although combined cornering and braking data to support this requirement do not exist, the probable correctness of this requirement can be inferred from the distortion of free-rolling force and moment properties by roadway curvature (SAE 760029). This implies the ne
44、ed for an impractically large round wheel machine to provide data indistinguishable from flat surface data. 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 would permit speeds betwee
45、n 1 and 160 km/h (0.6 and 100 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 speed, S, as realistically as possible consistent with the test machines capabilities. SAE INTERNATIONAL J
46、2675 NOV2017 Page 6 of 27 5.1.1.5 Ambient Temperature, TA, shall be maintained within the allowable range specified in Section 8, Selection and Preparation of Test Tires, and Section 9, Test Procedure. Ambient temperature affects tire temperature and tire temperature affects tire force and moment da
47、ta (SAE 770870). 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 forces, Fz, specified in Section 9, Test Procedure. The system shall accommodate the tire sizes to be tested. 5.1.2.1 The loading and
48、 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 in to 55.0 inch) in outside diameter with section widths up to 645 mm (25
49、.4 inch). 5.1.2.2 The loading mechanism shall be able to exert the normal forces required by the Test Procedure, Section 9, for the tire sizes to be tested. An ideal loading system would be able to exert normal forces magnitudes of up to 140 kN (31500 lb). 5.1.2.3 The positioning system and its supporting structure shall provide a slip angle, . It shall, as a minimum, permit incremental settin
