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 2012 SAE International All rights reserved. No part of this pub
3、lication 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
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2717_201206SURFACEVEHICLERECOMMENDEDPRACTICEJ2717 JUN2012 Issued 2006-04Revised 201
5、2-06Superseding J2717 APR2006 Tests to Define Tire Size (Geometry), Mass, and Inertias RATIONALEThis Recommended Practice was developed as part of a set of Recommended Practices intended to allow modelers to determine the parameters required by any of the common tire models for calculating spindle l
6、oads given the road surface profile from a single set of experimental results, and thus, to eliminate duplicate testing. This version addresses minor editorial problems found in previous versions. 1. SCOPE This SAE Recommended Practice describes a trio of test methods which determine basic tire size
7、 (geometry), mass, and moments of inertia. The methods apply to any tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for determining parameters for road load models and for comparative evaluations of the measured propertie
8、s in research and development.NOTE: Herein, road load models are models for predicting forces applied to the vehicle spindles during operation over irregular surfaces paved or unpaved. Within the context of this Recommended Practice, forces applied to the surface on which the tire is operating are n
9、ot considered. 1.1 Procedures Three procedures are specified. The first procedure determines the tires undeflected radius, section width, and section height. The second determines the mass of the tire and of the wheel on which the tire is mounted. The third procedure determines moments of inertia ab
10、out the three Cartesian axes defined in Recommended Practice SAE J2710.1.2 Test Machines No specific purpose built test machines are required to use the procedures in this Recommended Practice although individual test laboratories may have specific purpose built test machines for making certain meas
11、urements, for example, inertias. Each procedure can be applied using an ensemble of jigs and tools specific to itself. Example tools and jigs adequate for each procedure are specified within the Required Measurement Tools section of the description of each specific procedure. SAE J2717 Revised JUN20
12、12 Page 2 of 20 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 Commonwealth
13、Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J2047 Tire Performance Technology SAE J2429 Free-Rolling Cornering Test for Truck and Bus Tires SAE J2710 Modal Testing and Identification of Lower Order Tire Natural Frequencie
14、s of Radial Tires 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 of Aging on Force and Moment Properties of Radial Tires, M. G. Pottinger, K. D. Marshall, 1981.2.1.2 OSHA Publication Availa
15、ble from Rubber Manufacturers Association, 1400 K Street, NW, Suite 900, Washington, DC 20005, Tel: 202-682-4800, www.rma.org.OSHA Standard 1910.177 Servicing Multi-piece and Single Piece Rim Wheels - Available in wall chart form as #TTMP-7/952.1.3 ISO Publication Available from American National St
16、andards Institute, 25 West 43rd Street, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org.ISO/IEC 17025:2005 General requirements for the competence of testing and calibration laboratories 2.1.4 ASTM Publication Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Con
17、shohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.orgASTM F1502-05(2010) Standard Test Method for Static Measurements on Tires for Passenger Cars, Light Trucks, and Medium Duty Vehicles 2.1.5 FMVSS Publication Available from U.S. Department of Transportation, National Highway Traffic Safety Admi
18、nistration, Office of Communications and Consumer Information (NPO-502), 400 Seventh St., SW, Washington, DC 20590. FMVSS 139 New Pneumatic Radial Tires for Light Vehicles SAE J2717 Revised JUN2012 Page 3 of 20 3. DEFINITIONS The definitions that follow are of special meaning in this Recommended Pra
19、ctice and are either not contained in other Recommended Practices or are worded somewhat differently in this practice. 3.1 WHEEL A wheel is a rim together with the disc or spider that allows attachment of a rim to the vehicles hubs. A wheel cross-section schematic is shown in Figure 1. RimDiscSpindl
20、eFIGURE 1 - WHEEL CROSS-SECTION 3.2 MOMENTS OF INERTIA The moments of inertia are defined in the double primed axis system introduced in J2710. Figure 2 shows the J2710 axis system for the special case of no camber or inclination. That case applies in this Recommended Practice. The wheel is sketched
21、 in rear elevation. The view is forward along the X” - axis looking at the Y” - Z” plane. The systems origin is at the point that the spin axis intersects the wheel plane, which is the plane halfway between the rim flanges (J2047). The system is a right-handed, orthogonal, Cartesian system. The X” a
22、nd Z” axes lie in the wheel plane. The Y” - axis is to the right. If the tire is mounted with the tire face to the right, as if it were on the right side of a vehicle, Y” is outward. 3.2.1 Wheel Moments of Inertia 3.2.1.1 Wheel Moment of Inertia about the Y” - Axis This is the moment of inertia of t
23、he wheel alone about the Y” - Axis. 3.2.1.2 Wheel Moment of Inertia about the Z” - Axis This is the moment of inertia of the wheel alone about the Z” - Axis. The moment of inertia of the wheel about the X” - Axis is the same due to wheel symmetry.SAE J2717 Revised JUN2012 Page 4 of 20 Y”a aWheelPlan
24、eZ”SpindleWheelPlaneWheelPlaneWheelPlaneWheelPlaneWheelPlaneFIGURE 2 - REAR ELEVATION VIEW OF THE DOUBLE PRIMED AXIS SYSTEM 3.2.2 Tire Moments of Inertia 3.2.2.1 Tire Moment of Inertia about the Y” - Axis This is the moment of inertia of the tire alone about the Y” - Axis.3.2.2.2 Tire Moment of Iner
25、tia about the Z“ - Axis This is the moment of inertia of the tire alone about the Z” - Axis. The moment of inertia of the tire about the X” - Axis is the same due to tire symmetry.NOTE: The moments of inertia about the X” and Z” axes are not necessarily identical to those about axes through the cent
26、er of gravity of the tire-wheel assembly. This is due to a possible offset of the c.g. from the origin of the X”, Y”, Z” Axis System along the Y” - Axis. This offset, when present, arises from an offset wheel disc and tire asymmetries and requires application of the parallel-axis theorem, which is a
27、pplied in 13.5, and is discussed in all engineering dynamics books, as noted in Footnote 7. 3.2.3 Masses 3.2.3.1 Wheel Mass This is the mass of the wheel alone in the absence of a tire. 3.2.3.2 Tire Mass This is the mass of the tire alone in the absence of a wheel. SAE J2717 Revised JUN2012 Page 5 o
28、f 20 3.3 Tire Undeflected Radius This is one-half of the Tire Overall Diameter as defined in J2047. 3.4 Test A test is execution of the procedures described in this Recommended Practice one time on one tire at a single set of test conditions.3.5 Test Program A test program is a designed experiment i
29、nvolving a set of the tests described in this practice.14. NOMENCLATURE Table 1 lists the symbols used in this document. For further information on items not in Section 4 of this practice please see SAE J2047. TABLE 1 - SYMBOLS DEFINED Symbol Defined Term dTY” offset of the tire c.g. from the X”/Z”
30、- plane dWY” offset of the wheel c.g. from the X”/Z” - plane dWTY” offset of the wheel/tire c.g. from the X”/Z” -planedUnspecified Y” offset of the c.g. from the X”/Z” -planek Stiffness of Torsional Pendulum ICA Calibration Inertia for the Torsional Pendulum I0Residual Inertia of Torsional Pendulum
31、IYYTTire Inertia about the Y” - Axis IZZTTire Inertia about the Z” - Axis IYYWWheel Inertia about the Y” - Axis IZZWWheel Inertia about the Z” - Axis MTTire Mass MWWheel Mass MITInner Tube Mass p Inflation Pressure R0Tire Undeflected Radius Standard Deviation (Note Subscripts) SH Section Height SW S
32、ection Width T Period of Oscillation NOTE 1: If mass, Y” offset of the c.g., or inertia appears with the subscript, WT; this signifies that the entire tire/wheel assembly is being considered. NOTE 2: The period of oscillation may appear with a subscript indicating the state of the torsional pendulum
33、 when the data are taken. For example, T0would be the period if the only inertia present were the residual inertia. 1There are many experimental possibilities: repeated tests of the same tire, tests of the same tire under multiple test conditions, tests of tires with different specifications (design
34、 details), application of this test as part of a series of different tests, etc. SAE J2717 Revised JUN2012 Page 6 of 20 5. LABORATORY QUALITY SYSTEM REQUIREMENT The laboratory performing the procedures specified in this Recommended Practice shall have a quality system either conforming to ISO/IEC 17
35、025 or which can be shown to be functionally equivalent to ISO/IEC 17025. The elements of such a system are assumed below and are not, therefore, specifically called out within this practice. 6. CALIBRATION Calibrate all measuring tools in accordance with the mandates of the written plan required by
36、 the laboratory quality system referenced in Section 5. Calibration must exercise all measuring tools over substantially their full range of application and must be performed not less than once each year. The reference standards and instruments used in measuring tool calibration shall be traceable t
37、o the National Institute of Standards and Technology or other appropriate national standards organization with jurisdiction at the laboratorys location. Currently valid calibration certificates for reference standards and instruments shall be on file at the testing laboratory when the tools used in
38、accordance with this Recommended Practice are calibrated. Gains, offsets, and other pertinent performance measures and comments on the behavior of measuring tools arising from calibrations shall be kept permanently on file within the testing laboratorys archives and be available to customers on requ
39、est. 7. PREPARATION OF APPARATUS Preparation of the tools and jigs forming the apparatus used in each procedure shall ensure that the test setup meets calibration at the outset of each test program. The precise process control method used to verify readiness of the apparatus is likely to be unique t
40、o an individual test site, but must be specified in writing within the quality system of the laboratory. The results of process control experiments shall be available to customers on request. 8. TEST WHEELS Test wheels should ideally be those specified by the test requester or supplied by the test r
41、equester due to the intent of this Recommended Practice to provide mass and moment of inertia properties of the wheels as well as of the tires. Should the precise wheels be unavailable a rational alternative choice should be made with the concurrence of the test requester. In any case, test wheels s
42、hall meet the dimensional tolerances of original equipment wheels supplied on new vehicles and match the rim profile for the applicable tire as specified by the appropriate tire and rim standards association, for example, the Tire and Rim Association, Inc.9. SELECTION AND PREPARATION OF TEST TIRES 9
43、.1 Selecting the Tires for Good Comparability The purpose of the test must be carefully borne in mind when selecting test tires since tire properties depend on numerous factors besides the tire design and materials. It is especially important to properly account for storage history (SAE 810066) and
44、previous work history (SAE 770870). Due to the many questions that the test defined in this document may be used to address, specific tire selection recommendations can only be made for the case in which different tires are to be compared for pure design effects. In that case, all test tires should
45、be of approximately the same age, have been stored under essentially identical conditions, have experienced approximately the same exercise history, and have been sampled from production lots with similar statistical characteristics. SAE J2717 Revised JUN2012 Page 7 of 20 9.2 Inflation Pressure The
46、inflation pressure will significantly affect tire inflated geometry. Therefore, the appropriate test inflation pressure mustbe specified by the requester. Because tires typically operate at a temperature higher than that of the ambient air, operating inflation pressure is usually higher than cold in
47、flation pressure. If the purpose of testing is to simulate the running state, then the inflation pressure used in the test must be equivalent to the on-road operating inflation pressure. The laboratory is assumed to be capable of setting cold tire inflation pressure to within 1.7 kPa.29.3 Tire Prepa
48、ration Clean the tire surface of dirt, loose material, or other contaminants. Mount the test tire on the test requester specified testwheel. For rim wheels3used on large vehicles such as trucks, tractors, buses, and off-road machines, mounting and demounting shall be done in accordance with the prac
49、tices specified in OSHA 1910.177. OSHA 1910.177 does not apply to the servicing of rim wheels used on automobiles or on pickup trucks and vans utilizing automobile tires or truck tires designated “LT”. The wheel used shall meet the specifications noted in Section 8. After mounting, the tire shall be marked with three sets of radial lines from bead-to-bead. These lines shall be spaced every 120 degrees circumferentially around the spin
