1、Designation: E1170 97 (Reapproved 2017)Standard Practices forSimulating Vehicular Response to Longitudinal Profiles ofTraveled Surfaces1This standard is issued under the fixed designation E1170; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These practices cover the calculation of vehicular re-sponse to longitudinal profiles of trave
3、led surface roughness.1.2 These practices utilize computer simulations to obtaintwo vehicle responses: (1) axle-body (sprung mass) motion or(2) body (sprung mass) acceleration, as a function of time ordistance.1.3 These practices present standard vehicle simulations(quarter, half, and full car) for
4、use in the calculations.1.4 The values stated in SI units are to be regarded as thestandard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health pract
5、ices and determine the applica-bility of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and
6、 Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E950 Test Method for Measuring the Longitudinal Profile ofTraveled Surfaces with an Accelerometer EstablishedInertial Profiling Reference2.2 ISO Standard:3IS
7、O 2631 Guide for the Evaluation of Human Exposure toWhole-Body Vibration3. Summary of Practices3.1 These practices use a measured profile (see Test MethodE950) or a synthesized profile as part of a vehicle simulation toobtain vehicle response.3.2 The first practice for obtaining vehicle response use
8、ssimulation of a quarter-car or half-car model. The output is theaccumulated relative motion between the sprung and unsprungvehicle masses, of the simulated vehicle, for a predetermineddistance. The units are accumulated relative motion per unit ofdistance traveled (m/km or in./mile). For example, t
9、he quarter-car simulation is used when a Bureau of Public RoadsBPR/roadmeter is to be simulated, and the half-car model (orthe quarter car with the average of the left and right elevationprofile input) is used when a road meter is to be simulated.3.3 The second practice uses either a quarter-car, ha
10、lf-car, orfull-car simulation to obtain vehicle body acceleration. Theacceleration history can be computed as a function of time ordistance, or both. One application of this practice is to use theacceleration history in a ride quality evaluation, such as theISO Guide 2631.3.4 For all calculations, a
11、 vehicle test speed is selected andmaintained throughout the calculation. Pertinent informationaffecting the results must be noted.4. Significance and Use4.1 These practices provide a means for evaluating traveledsurface-roughness characteristics directly from a measuredprofile. The calculated value
12、s represent vehicular response totraveled surface roughness.4.2 These practices provide a means of calibrating response-type road-roughness measuring equipment.45. Apparatus5.1 ComputerThe computer is used to calculate accelera-tion and displacement of vehicle response to a traveled surfaceprofile,
13、using a synthesized profile or a profile obtained inaccordance with Test Method E950 as the input. Filtering shall1These practices are under the jurisdiction of ASTM Committee E17 on Vehicle- Pavement Systems and are the direct responsibility of Subcommittee E17.33 onMethodology for Analyzing Paveme
14、nt Roughness.Current edition approved July 1, 2017. Published July 2017. Originally approvedin 1987. Last previous edition approved in 2012 as E1170 97 (2012). DOI:10.1520/E1170-97R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm
15、.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Gillespie, T. D., Sayers, M. W., and Segel, L., “
16、Calibration and Correlation ofResponse-Type Road Roughness Measuring Systems,” NCHRP Report 228, 1980.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recogniz
17、ed principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1be provided to permit calculation, without attenuation, atfrequenci
18、es as small as 0.1 Hz at speeds of 15 to 90 Km/h (10to 55 mph). Computation may be analog or digital. Noisewithin the computer shall be no more than one quarter of theintended resolution. It is recommended that a 16-bit or betterdigital computer be used.5.2 Data-Storage DeviceA data-storage device s
19、hall beprovided for the reading of profiles and the recording andlong-term storage of computed data. Profile data shall be scaledto maintain resolution of 0.025 mm (0.001 in.) and to accom-modate the full range of amplitudes encountered during normalprofile-measuring operations. The device shall not
20、 contributeto the recorded data any noise amplitude larger than 0.025 mm(0.001 in.).5.3 Digital Profile RecordingsRoad-roughness profilesshall be obtained in accordance with Test Method E950 orsynthesized. The profile must be recorded at intervals nogreater than one-third of the wavelength required
21、for accuraterepresentation of the traveled surface for the intended use ofthe data. For most applications a sample interval of 600 mm(2 ft) will give a valid representation for all types of roadsurfaces except where the roughness is extremely localized andtherefore could be missed, in which case a s
22、ample interval of150 mm (6 in.) should be used. When more than one path of atraveled surface is measured, the recorded profile data for thepaths shall be at the same longitudinal location along themeasured profiles. The recorded profile shall include all of thenoted field data described in the Proce
23、dure (Data Acquisition)and Report sections of Test Method E950. The length of theroad-roughness profile must be reported with the results;however, caution must be exercised to ensure that transients inthe simulation do not influence the results. It is recommendedthat at least 160 m (0.1 miles) of pr
24、ofile, preceding the testsection, plus the desired test section be used as input insimulation to eliminate the effects of transients.6. Vehicle Simulation Programs6.1 These practices use one of four vehicle simulations:5aquarter car, a half car, a full car with four-wheel independentsuspension, and
25、a full car with a solid rear axle. Althoughseveral methods for solving the differential equations areavailable, the Runge-Kutta is described in NCHRP Report228.4The parametric models in Figs. 1-4 (such as the lumpedparameter model) and the coordinate system defined constitutethe standard practice. T
26、he analytic representation of the modeland the methods of implementation need not be the same asoutlined in the appendix.6.1.1 Quarter-Car Simulation Model:6.1.1.1 The quarter car is modeled as shown in Fig. 1, withz1, as the vehicle-body (sprung mass) displacement, z2as thetire (unsprung mass) disp
27、lacement, and the zpas the longitu-dinal profile.6.1.1.2 The relative motion between the body and the axle,Z, is defined as:Z 5 z12 z2(1)The equation of motion for the quarter-car model is given inX1.1. The parameters used for the quarter-car model are5Wambold, J. C., Henry, J. J., and Yeh, E. C., “
28、Methodology for AnalyzingPavement Condition Data” (Volume I and II, Final Report), Report No. FHWA/RD-83/094 and FHWA/RD-83/095, Federal Highway Administration, January 1984.FIG. 1 Quarter-Car Simulation ModelFIG. 2 Half-Car ModelFIG. 3 Full-Car with Independent SuspensionE1170 97 (2017)2normalized
29、by the body mass, M1. The other vehicle param-eters are: the vehicle spring constant, K1; the damper value, C1;the axle-wheel mass, M2; the tire stiffness, K2; and the tiredamping constant, C2. Values for these parameters are given inTable 1.6.2 Half-Car Simulation ModelThe half-car model isconstruc
30、ted by using one half of a rigid vehicle and is made upof two quarter cars at the right and left tracks. The model forthe half car is shown in Fig. 2, and the associated parametersare given in Table 2. The equation of motion is given in X1.2.The relative motion between the body and the axle, Z, isde
31、fined as Z=z312 (z1+ z2). The mass of the axle, Maandthe moment of inertia of the axle, Iamust be set to zero whenthe half car being modeled has an independent wheel suspen-sion. Ibrepresents the moment of inertia of the car body and brepresents the wheel track.6.3 Full-Car Simulation Model with Fou
32、r-Wheel Indepen-dent Suspension:6.3.1 This model is an expansion of the half-car simulationmodel. Two more wheel and pitch motions are added to makeit a seven-degree-of-freedom model. This model is shown inFig. 3 and the vehicle parameters are given in Table 3.6.3.2 The equation of motion is develop
33、ed similarly to thatin the half-car model and the tire damping is again taken aszero to simplify the equations.The equations are given in X1.3.6.4 Full-Car Simulation Model with a Rear Axle:6.4.1 This model is a modification of the full-car model tochange the rear suspension to a solid axle. The mod
34、el is shownin Fig. 4. Again, the tire damping is taken as zero to simplifythe equations. The equations are given in X1.4.6.4.2 The values of the parameters Ix, Iw, and MFare thesame as in the model for the full car with independentsuspension, except that the additional parameter, axle momentof inert
35、ia, Iaxis used.7. Example Applications7.1 Displacement per Length of Travel:FIG. 4 Full-Car Model with Solid Rear AxleTABLE 1 Quarter-Car Vehicle Physical ConstantsSimulated VehicleParameterBPRRoughometerRide Meter-VehicleMountedRide Meter-TrailerIRIK1/M1129 s263 s2125 s263.3K2/M1643 s2653 s2622 s26
36、53M2/M10.16 0.15 0.26 0.15C1/M13.9 s16.0 s18.0 s16.0C2/M100 00TABLE 2 Half-Car Vehicle Physical ConstantsAParameter Ride-Meter Vehicle MountedRide-MeterTrailerK1/MH32 s257.5 s2K2/MH326 s2311 s2M2/MH0.075 0.125C1/MH3 s14 s1C2/MH00Ma/MH0.30 0.50(for model with rear axle)0(for model with independent re
37、ar suspension)IH/(MHb2)Ia/IH0.420.360.420.6(for model with rear axle)0(for model with independent rear suspension)b 1.8 m 1.8 mAThe values apply to the rear half of a vehicle.E1170 97 (2017)37.1.1 Inches per MileAn improved method of computinginches per mile (IPM) has been proposed by Gillespie, Say
38、ers,and Segel.4Quantization, as used in current road meters, doesnot truly reflect the axle-body movement. Therefore, IPM isdefined as:IPM 5(i51N? Zi2 Zi11?/distance (2)where:Zi= relative maximum or minimum value of the axle-bodymovement.7.1.2 International Roughness Index (IRI)The IRI comesfrom the
39、 1982 World Bank International Road RoughnessExperiment in Brazil. The IRI is the measurement of thedisplacement of the sprung mass to unsprung mass of aquarter-car model and is reported in units of displacement perlength of travel. The method uses a standard quarter-carmodels response to longitudin
40、al profile measurements.7.1.3 These IPM values are calculated on a continuous basisrather than in increments, and are considerably different fromthose obtained by current road meters.7.2 Ride Quality Analysis:7.2.1 The most commonly used standard is ISO 2631, thathas a tabular format and uses human-
41、body acceleration topredict the exposure time for human discomfort or fatigue. ISO2631 can be converted to an index system by calculating thetime-to-discomfort for every frequency interval from 1 Hz to80 Hz. For ISO 2631, the usual input to the program isvehicle-body (sprung mass) acceleration. The
42、analysis uses aFast Fourier Transform (FFT) to obtain the space frequencyspectrum of the acceleration history. The selected vehiclespecifications and speed produce the vehicle-body accelerationspectrum. The seat is considered as having negligible effect onthe human-body acceleration in the range of
43、1 Hz to 80 Hz.47.2.2 Ride Number (RN)During the 1980s, the ride num-ber concept for estimating pavement ride quality from surfaceprofile measurements was developed in a National CooperativeHighway research project. Various papers have compared theperformance of ride number transforms and found it to
44、 besuperior to other ride quality transforms, producing estimatesof pavement ride quality with the highest correlation to themeasured subjective ride quality and with he lowest Standarderror.7.2.3 After the acceleration frequency spectrum iscalculated, the model in ISO 2631 is applied. This modeldet
45、ermines the exposure time of reduced-comfort boundary orthe fatigue of a human body from the frequency spectrum ofthe seat vertical acceleration (Fig. 5). The details for calculat-ing the exposure times for reduced comfort or fatigue are givenin NCHRP Report 228.4An alternative for calculating a rid
46、eindex, developed at the University of Virginia,6is also pre-sented in NCHRP Report 228.48. Calibration8.1 If a digital analysis is used, calibration is required whenthe system is installed. If an analog computer is used, thesystem shall be calibrated on a periodic basis. At present, nostandard road
47、 profile is available for such a calibration. It issuggested that each agency adopt a range of profile records foruse in calibrating its complete system.9. Report9.1 Report the following information for each practice:9.1.1 Data from profiles obtained in accordance with TestMethod E950 including date
48、, the time of day of themeasurement, or the date of the synthesized profile,9.1.2 Vehicle simulation program used,9.1.3 Speed of simulations,9.1.4 Vehicle-parameter values used if other than thosespecified in these practices, and9.1.5 Results of the analysis.6Richards, L. G., Jacobson, I. D., and Pe
49、pler, R. D., “Ride Quality Models forDiverse Transportation Systems,” Transportation Research Record, Vol 774, 1980,pp. 3945.TABLE 3 Full-Car Vehicle Physical ConstantsParameter Value Parameter ValueK1/MF16 s2Ix/MFb20.14K2/MF163 s2Iy/MFL2 A0.19M2/MF0.038 b 1.8 mC1/MF1.5 s1L/bA1.44C2/MF0 h/bA0.5Iax/MFb2with axle 0.022without axle 0AThe wheel base is L, and the body height (center of gravity (cg) abovesuspension) is h.NOTE 1Vertical (az) acceleration limits as a function of exposure timeand frequency (center frequency of a third-octave band): “f
