ASTM F2711-2008 Standard Test Methods for Bicycle Frames《自行车车架的标准试验方法》.pdf

1、Designation: F 2711 08Standard Test Methods forBicycle Frames1This standard is issued under the fixed designation F 2711; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates

2、the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods establish procedures for conductingtests to determine the structural performance properties ofbicycle frames.1.2 These test methods describe mechan

3、ical tests for deter-mining the following performance properties:1.2.1 Frame FatigueHorizontal Loading,1.2.2 Frame FatigueVertical Loading, and1.2.3 Frame Impact Strength.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 T

4、his 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 practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Docume

5、nts2.1 ASTM Standards:2E4 Practices for Force Verification of Testing Machines3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bicycle, ntwo-wheeled, single track, articulated ve-hicle that is solely human powered.3.1.2 bicycle fork, nstructural connection between thefront whee

6、l and the frame.3.1.2.1 DiscussionThe fork transmits steering torquefrom the handlebars to the front wheel.3.1.3 bicycle frame, nstructural member that supports theseat with rear connection for the rear wheel, front connectionvia the head tube for the fork and lower connection for thecrank/pedal ass

7、embly.3.1.4 bottom bracket shell, nstructural member of theframe that houses the assembly that supports the bearings,which support the cranks.3.1.5 crank, nlever arm that receives human energy astorque to convert into bicycle motion.3.1.6 crown race seat, nposition on the fork where thelower steerin

8、g axis bearing sits.3.1.7 down tube, nlower structural connection betweenthe head tube and the bottom bracket shell.3.1.8 dropout centerline, nhub-mounting axis that passesthrough both right and left dropouts.3.1.9 front dropout, narea where the front wheel hubconnects to the fork.3.1.10 head tube,

9、nforward most structural member of theframe, which provides an interface through top, and bottombearings for the fork.3.1.10.1 DiscussionThe head tube is connected to the seattube through the top tube and the down tube.3.1.11 initial running displacement, naverage displace-ment between approximately

10、 500 and 1000 cycles during adurability fatigue test.3.1.12 normal attitude, nintended position of the bicycleframe when in continuous straight-line motion on a flat surface.3.1.13 rake, nstraight-line distance from the front axlecenter to the perpendicular of the steering axis.3.1.14 rear dropout,

11、narea where the rear wheel hubconnects to the lower rear and the upper rear frame members.3.1.15 sag, namount of compression in a suspension unit,given in a percentage.3.1.16 seat post, nstructural component that connects theseat to the seat tube.3.1.17 seat tube, nstructural member of the frame int

12、owhich the seat post inserts.3.1.18 steerer tube, nsection of the bicycle fork that ishoused within the head tube and bearing assemblies.3.1.19 top tube, nupper structural connection between thehead tube and the seat tube.3.2 Acronyms:3.2.1 OEM, noriginal equipment from manufacturer1This test method

13、 is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.10 onBicycles.Current edition approved April 1, 2008. Published May 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custom

14、er Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.3 Symbols:L = fork length, a straig

15、ht-line measure from the crown raceseat to the center of the front axle.d = deflection of test fork.4. Summary of Test Methods4.1 Horizontal Loading Durability Fatigue TestThis testmethod restrains the frame at the rear dropouts (see Fig. 1). Acyclic load is applied along the x-axis at the front dro

16、pouts. Thenumber of cycles is measured. The magnitude of the load, andthe minimum number of cycles, are determined by the speci-fication standard.4.2 Vertical Loading Durability Fatigue TestThis testmethod restrains the frame at the rear dropouts, and allows freerolling at the fork (see Fig. 2).Acyc

17、lic load is applied along theZ-axis behind the seat post. The number of cycles is measured.The magnitude of the load, and the minimum number of cycles,are determined by the specification standard.4.3 Impact Strength TestThis test method restrains theframe vertically at the rear dropouts (see Fig. 3)

18、. A mass isdropped onto a roller assembly attached to the fork. Permanentset is measured. The height of the drop is determined by thespecification standard.5. Significance and Use5.1 These tests are used to verify the durability and strengthof a bicycle frame.6. Apparatus6.1 Requirements for Test Fo

19、rks:6.1.1 The test forks shall be designed to mount in a mannersimilar to the OEM fork, or in a manner using typical bicycleassembly procedures.6.1.2 The test forks, when mounted, shall be the samelength, L, as the longest fork designed for use with the frameand have a rake of 45 6 6 mm. When the te

20、st fork is used inplace of an OEM Suspension fork, the length is determined bythe dropout position when the suspension fork is compressedno more than 20 % of its maximum amount of travel.6.1.3 The deflection of a test fork is measured at the frontaxle center, resulting from the application of a vert

21、ical 1200 Nload at that point. The fork is fixed in position only at thesteerer tube by a v-block with minimum length of 76 mm. Thesteerer tube is fixed horizontally with the crown race seatadjacent to the v-block.6.1.4 The deflection ratio for the Test fork for the HorizontalLoading Fatigue test an

22、d the Vertical Loading Fatigue test shallnot exceed the value of 1.0 when computed as follows:Deflection ratio 5K 3 10 000 3dL3Where:K (a constant) = 1417 for L and d in millimetres.(For example, a fork length of 460 mm, the maximumacceptable fork deflection (d) would be 6.9 mm. Similarly fora fork

23、length of 330 mm, the maximum deflection is 2.5 mm.)6.1.5 The deflection ratio for the Test fork for the Impacttest shall not exceed the value of 1.0 when computed asfollows:Deflection ratio 5K 3 10 000 3dL3Where:K = 709 for L and d in millimetres.6.2 Horizontal Loading Durability Fatigue Test:6.2.1

24、 A fixture is required to restrain the frame at the reardropouts, while allowing free rotation about the axle (see Fig.1). In the case of a suspension frame, the suspension must belocked in a position equivalent to the manufacturers recom-mendation for sag, or 25 % sag if none was recommended. Ifthe

25、 suspension does not permit locking, then replace thesuspension unit with a solid link providing the equivalent saggeometry.6.2.2 A test fork meeting the requirements for this test (see6.1) shall be used.6.2.3 The fork shall be attached to the bicycle frame headtube using typical bicycle assembly pr

26、actices.6.2.4 The fork assembly shall be restrained at the dropoutsin such a way that allows translation along the X-axis, androtation about the Y-axis.6.2.5 The front and rear dropouts are to be equal in heightwhen the frame and fork assembly is fixtured.FIG. 1 Horizontal Fatigue TestF 2711 0826.2.

27、6 An actuator mounted load cell or equivalent apparatusthat is capable of providing a reversible load of constantamplitude shall be attached to the front dropouts or front axle,without constricting the rotational freedom of the fork assem-bly.6.2.7 This apparatus shall allow cyclic load application

28、tothe front dropouts in a longitudinal direction along the bicyclecenterline.6.3 Vertical Loading Durability Fatigue Test:6.3.1 A fixture is required to restrain the frame at the reardropouts, while allowing free rotation about the rear axle (Fig.2). In the case of a suspension frame, the suspension

29、 must belocked in a position equivalent to the manufacturers recom-mendation for sag, or 25 % sag if none was recommended. Ifthe suspension does not permit locking, then replace thesuspension unit with a solid link providing the equivalent saggeometry.6.3.2 A test fork meeting the requirements for t

30、his test (see6.1) shall be used.6.3.3 The fork shall be attached to the bicycle frame headtube using typical bicycle assembly practices.6.3.4 The fork assembly shall be restrained at the dropoutsin such a way that allows translation along the X-axis (see Fig.4); and free rotation of the fork assembl

31、y about the front axle;while movement in the Y-axis and Z-axis is constrained.6.3.5 The front and rear dropouts are to be equal heightwhen the frame and fork assembly is fixtured.6.3.6 A round solid steel loading bar equivalent to a seatpost shall be inserted into the top of the seat tube, and secur

32、edto the seat tube by the manufacturers instructions using thenormal clamp. A horizontal rearward extension shall be se-curely attached to the top of this bar such that its height, h, isequal to the maximum saddle height for that particular frame,as shown in Fig. 2. The extension bar shall permit lo

33、ading witha 70 mm rearward offset.6.3.7 An actuator mounted load cell or equivalent apparatusthat is capable of providing a reversible load, is attached to therearward extension and aligned in the vertical, downward,direction.6.4 Impact Strength Test:6.4.1 A fixture is required to restrain the frame

34、 at the reardropouts, while holding the frame securely in a verticalorientation (Fig. 3). In the case of a suspension frame, thesuspension must be locked in a position equivalent to themanufacturers recommendation for sag, or 25 % sag if nonewas recommended. If the suspension does not permit locking

35、,then replace the suspension unit with a solid link providing theequivalent sag geometry.6.4.2 A test fork meeting the requirements for this test (see6.1) shall be used.6.4.3 The fork shall be attached to the bicycle frame headtube using typical bicycle assembly practices.6.4.4 The front and rear dr

36、opouts of the frame are to be onthe same vertical centerline when the frame and fork assemblyis set into the fixture.6.4.5 A free-running low-mass roller, 1 kg maximum, andwith a maximum diameter of 55 mm, shall be attached to thefork axle (Fig. 3).6.4.6 A free-falling, guided 22.5-kg weight shall b

37、e used toimpact the low-mass roller at a point in-line with the wheelcenterline and against the direction of bicycle motion in normalattitude.7. Calibration and Standardization7.1 Durability Fatigue Tests:7.1.1 The test apparatus shall be calibrated to meet PracticesE4, for accuracy within 61 % of s

38、pecified load.7.1.2 The load shall be monitored to an accuracy of 62.5 %through a load cell or other suitable load-measuring device.FIG. 2 Vertical Fatigue TestF 2711 0837.1.3 The displacement shall be monitored to within62.5 %.7.1.4 Rearward force is defined as compression (denotedwith minus () sig

39、n); forward force is defined as tension(denoted with plus (+) sign). The number of cycles is mea-sured.7.1.5 All tolerances on the test fixture shall be within 61%.7.2 Impact Test:7.2.1 The test weight shall be accurate to within 62%ofspecified weight.8. Conditioning8.1 Tests are to be performed at

40、room temperature of 18 to35C.8.2 All tests are to be performed on initially unused frames.8.3 The same frame may be used in successive tests of thisstandard, except as noted in 8.5. If it does not pass a subsequenttest after passing its first test, then that particular test isinconclusive and must b

41、e repeated with an unfailed frame.8.4 No frame shall be used for the same test more than once.8.5 No frame shall be used for successive testing after beingimpact tested, as described in 9.3.9. Procedure9.1 Horizontal Durability Fatigue Test:9.1.1 Assemble the frame onto the test apparatus, as de-scr

42、ibed in 6.2.9.1.2 Begin applying the specified cyclic load at 1 Hz. Toexceeda1Hzload application rate, the following criteria mustbe met. The running displacement shall be within 63%ofthedisplacement at 1 Hz.9.1.3 Conclude the test when the specified minimum num-ber of cycles is attained, or if/when

43、 fracture occurs. Fracture isdefined as the following:9.1.3.1 If using displacement control to perform the test,fracture is the point at which the load drops below 95 % of themaximum specified running load.FIG. 3 Frame Impact TestF 2711 0849.1.3.2 If using force control to perform the test, fracture

44、 isa crack, tear, or separation at the surface of the frame that isvisible to the unaided eye. Inspection of the frame for theexistence of fracture must occur when displacement exceeds3.0 mm from initial running displacement or previous inspec-tion.9.2 Vertical Durability Fatigue Test:9.2.1 Assemble

45、 the frame onto the test apparatus, as de-scribed in 6.3.9.2.2 Begin applying the specified cyclic load at 1 Hz. Torun the test at a greater frequency than 1 Hz, the followingcriteria must be met. The running displacement shall be within63 % of the displacement at 1 Hz.9.2.3 Conclude the test when t

46、he specified minimum num-ber of cycles is attained, or if/when fracture occurs. Fracture isdefined as the following:9.2.3.1 If using displacement control to perform the test,fracture is the point at which the load drops below 95 % of themaximum specified running load.9.2.3.2 If using force control t

47、o perform the test, fracture isa crack, tear, or separation at the surface of the frame that isvisible to the unaided eye. Inspection of the frame for theexistence of fracture must occur when displacement exceeds3.0 mm from initial running displacement or previous inspec-tion.9.3 Impact Strength Tes

48、t:9.3.1 Mount the frame and fork assembly in the verticalplane, as described in 6.4, with the front and rear dropouts onthe same vertical centerline.9.3.2 Connect the fork roller assembly to fork dropouts.9.3.3 Measure the distance between the axles (wheelbase)with the weight resting on the fork rol

49、ler.9.3.4 Raise the weight to the appropriate drop height, asdefined by the specification standard.9.3.5 Release the weight onto the fork roller. The weightwill bounce (this is normal and permitted).9.3.6 After the weight comes to rest, repeat the wheelbasemeasurementthis is the permanent set of the frame and fork.10. Precision and Bias10.1 No information is presented concerning the precisionor bias of these test methods for measuring the durability andstrength of a bicycle frame since the test result is non-quantitative.11. Keywords11.1 actuator; b