ASTM D4475-2002(2016) Standard Test Method for Apparent Horizontal Shear Strength of Pultruded Reinforced Plastic Rods By the Short-Beam Method《采用短梁法测定拉挤成型增强塑料棒材的表观水平剪切强度的标准试验方法》.pdf

1、Designation: D4475 02 (Reapproved 2016)Standard Test Method forApparent Horizontal Shear Strength of Pultruded ReinforcedPlastic Rods By the Short-Beam Method1This standard is issued under the fixed designation D4475; the number immediately following the designation indicates the year oforiginal ado

2、ption or, in the case of 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 This test method covers the determination of the appar-ent horizontal s

3、hear strength of fiber reinforced plastic rods.The specimen is a short beam in the form of lengths ofpultruded rods. This test method is applicable to all types ofparallel-fiber-reinforced plastic rod samples.1.2 This test method is primarily used for quality controland specification purposes (see 4

4、.1).1.3 The values stated in SI units are to be regarded asstandard.1.4 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 practices and determine the a

5、pplica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingE4 Practices for Force Verification of Testing MachinesE691 Practice for Conducting an Interlabor

6、atory Study toDetermine the Precision of a Test Method3. Summary of Test Method3.1 The horizontal-shear test specimen is center-loaded asshown in Fig. 1. The ends of the specimens rest on twosupports that allow the specimen to bend, the load beingapplied by means of a loading nose at midpoint along

7、thesupport span, as shown in Fig. 2.3.2 The specimen is deflected until a shear failure occurs atthe midplane of the horizontally supported rod.4. Significance and Use4.1 Apparent shear strength determined by this test methodis useful for quality control and specification purposes. It isalso applica

8、ble to research and development programs con-cerned with interlaminar-shear strength. The apparent shearstrength obtained by this test method cannot be used for designpurposes, but can be utilized for comparative testing ofcomposite materials, if all failures are in horizontal shear.4.2 It is recomm

9、ended that control samples be fabricatedwith each research test series and that care be used to compareeach set of controls with corresponding test series run atdifferent times.5. Apparatus5.1 Testing MachineAproperly calibrated testing machinethat can be operated at a constant rate of crosshead mot

10、ion, andin which the error in the load measuring system shall notexceed 61 % of the maximum load expected to be measured.The load-indicating mechanism shall be essentially free ofinertia lag at the crosshead rate used. The accuracy of thetesting machine shall be verified in accordance with Practices

11、E4.5.2 Loading Nose and SupportsShown in Fig. 2 and Fig.3. The loading nose shall be a suitable steel rod with a groovein the diameter of the pultruded rod machined in its lower end.The groove diameter shall always have a plus tolerance andzero negative tolerance. The bottom support shall be adjusta

12、bleto allow for testing at various span/diameter ratios. The surfaceof the groove shall be free of indentation and burrs, with allsharp edges relieved.5.3 MicrometersSuitable micrometers for measuring thediameter of the test specimen to an incremental discriminationof at least 0.025 mm (0.001 in.) s

13、hall be used.6. Test Specimen6.1 The specimen shall be cut from the pultruded rod to alength of one diameter greater than the test span and to atolerance of plus or minus 0.1 times the diameter.6.2 Number of SpecimensThe number of test specimens isoptional. However, a minimum of five specimens is re

14、quired toobtain a satisfactory average and standard deviation.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.18 on Reinforced Thermoset-ting Plastics.Current edition approved April 1, 2016. Published April 2016. Origi

15、nallyapproved in 1985. Last previous edition approved in 2008 as D4475 - 02(2008).DOI: 10.1520/D4475-02R16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stand

16、ards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17. Conditioning7.1 ConditioningCondition the test specimens at 23 62C (73.4

17、 6 3.6F) and 50 6 5 % relative humidity for not lessthan 40 h prior to test, in accordance with Procedure A ofPractice D618 for those tests where conditioning is required. Incases of disagreement, the tolerances shall be 61C (61.8F)and 62 % relative humidity. These conditions are recom-mended for re

18、search and development trials, but not necessar-ily for quality control. However, temperature control to 22.2 65.6C (72 6 10F) is recommended for quality control.7.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C (73.4 6 3.6F) and 50 6 5%relative humidity, unless othe

19、rwise specified in the test meth-ods. In cases of disagreement, the tolerances shall be 61C(61.8F) and 62 % relative humidity.7.3 Preconditioning in other environments to simulatespecified conditions and durations is permissible.7.4 Testing in other environmental conditions is permis-sible.8. Speed

20、of Testing8.1 Test the specimen at a rate of crosshead motion of 1.3mm (0.05 in.)/min.NOTE 2The test time should be recorded, and, if the test takes lessthan 20 s, the rate of crosshead motion should be decreased. If the testtakes over 200 s, the crosshead rate should be increased gradually, or inst

21、eps, until the time to complete the test is less than 200 s.9. Procedure9.1 Before conditioning or testing, measure the diameter ofeach specimen to the nearest 0.025 mm (0.001 in.) at midpoint.9.2 Place the rod test specimen in the test fixture, as shownin Fig. 1. Align the specimen so that its midp

22、oint is centeredand its long axis is perpendicular to the loading nose. Adjustthe side supports to the span previously determined. Suggestedspan-to-diameter ratios are from 3 to 1 up to 6 to 1. Theobtainment of shear fractures during the test is a majorconsideration in determining span length.NOTE 3

23、Experimental data indicates that shear strength is a function ofsupport span-to-specimen diameter ratio in most materials. When writingspecifications, both the specimen diameter and the span-to-diameter ratioshould be specified.9.3 Apply the load to the specimen at the specified cross-head rate. Rec

24、ord the load to break for each specimen(maximum load on load-indicating mechanism). At times,when testing pultruded rods in various environments, speci-mens do not consistently fail in shear, especially when theincorrect span-to-depth ratio is chosen. It is, therefore, veryimportant to record the ty

25、pe of break (shear or tensile) thatoccurs. For research purposes, it is also useful to record theposition of the shear plane relative to the specimen center line.FIG. 1 Test AssemblyFIG. 2 Span Configuration for 3D Span. Span. May Also Be 4D,5D, or 6D, as Required to Achieve Shear Mode of FailureFIG

26、. 3 Anvil DimensionsD4475 02 (2016)210. Retest10.1 Values for properties at break shall not be calculatedfor any specimen that breaks at some obvious, fortuitous flaw,unless such flaws constitute a variable being studied. Retestsshall be made for any specimen on which values are notcalculated. Shoul

27、d a specimen fail in a manner other thanhorizontal shear, the value shall be discarded and a retest shallbe made. However, some of the specimens may not show adistinct failure mode, particularly after preconditioning. It issuggested that some form of chart movement, such as chartspeed or a deflectom

28、eter, be used to help determine the fracturepoint. This is normally the first major load reduction or suddenchange in slope of the load-deflection curve.11. Calculations11.1 Calculate the apparent shear strength as follows:S 5 0.849 P/d2(1)where:S = apparent shear strength, N/m2, (or psi),P = breaki

29、ng load, N, (or lbf), andd = diameter of specimen, m, (or in.).11.2 Arithmetic Mean for Each Series of TestsCalculatethe arithmetic mean of all values obtained to three significantfigures and report as the “average value.”11.3 Standard DeviationCalculate the standard deviation(estimated) as follows

30、and report to two significant figures:s 5 =(X22 nX 2!/n 2 1! (2)where:s = estimated standard deviation,X = value of a single observation,n = number of observations, andX= arithmetic mean of the set of observations.12. Report12.1 The report shall include the following:12.1.1 Complete identification o

31、f the material tested, includ-ing type, source, form, principle dimensions, and previoushistory,12.1.2 Fabrication procedure,12.1.3 Diameter of specimen,12.1.4 Conditioning procedure used,12.1.5 Atmospheric conditions in the test room,12.1.6 Number of specimens tested,12.1.7 Rate of crosshead motion

32、,12.1.8 Span length,12.1.9 Length of specimens,12.1.10 Type of failure,12.1.11 Apparent horizontal shear strength of eachspecimen, average value, and standard deviation,12.1.12 Location of failure, or method of determining fail-ure from curve,12.1.13 Average fiber content, percent by weight, and12.1

33、.14 Date of test.13. Precision and Bias313.1 Table 1 is based on a round robin conducted in 1984 inaccordance with Practice E691, involving three materialstested by eleven laboratories. For each material, all the sampleswere prepared at one source, but the individual specimens wereprepared at the la

34、boratories which tested them. Each test resultwas the average of five individual determinations. Each labo-ratory obtained two test results for each material. Tests wereconducted at room temperature and 150F. (WarningTheexplanation of “r” and “R” in 13.2.1 and 13.2.2 are onlyintended to present a me

35、aningful way of considering theapproximate precision of this test method. The data in Table 1should not be applied to acceptance or rejection of materials, asthese data apply only to the materials tested in the round robinand are unlikely to be rigorously representative of other lots,formulations, c

36、onditions, materials, or laboratories. Users ofthis test method should apply the principles outlined in PracticeE691 to generate data specific to their materials and laboratory(or between specific laboratories). The principles of 13.2 13.2.2 would then be valid for such data.)13.2 Concept of “r” and

37、 “R” in Table 1If Srand SRhavebeen calculated from a large enough body of data, and for testresults that were averages from testing two specimens for eachtest result, then:13.2.1 Repeatability: Two results obtained within one labo-ratory shall be judged not equivalent if they differ by more thanthe

38、“r” value for that material. “r” is the interval representingthe critical difference between two test results for the samematerial, obtained by the same operator using the sameequipment on the same day in the same laboratory.13.2.2 Reproducibility: Two test results obtained by differ-ent laboratorie

39、s shall be judged not equivalent if they differ bymore than the “R” value for that material. “R” is the intervalrepresenting the critical difference between two test results for3Supporting data are available at ASTM Headquarters. Request RR:D20-1118.TABLE 1 Precision StatementShear Strength, 103psiR

40、oom TemperatureValues in the units of psiMaterialRodDiameterMean SrASRBIrCIRDVinyl ester 0.85 in. 10.2 0.236 0.519 0.665 1.47Vinyl ester 1.00 in. 9.14 0.161 0.374 0.456 1.06Polyester 1.20 in. 8.23 0.182 0.854 0.515 2.42150FVinyl ester 0.85 in. 7.70 0.245 0.548 0.693 1.55Vinyl ester 1.00 in. 7.14 0.1

41、65 0.415 0.467 1.17Polyester 1.20 in. 6.83 0.111 0.412 0.314 1.17ASr= within laboratory standard deviation for the indicated material. It is obtainedby pooling the within-laboratory standard deviations of the test results for all of theparticipating laboratories:Sr5 ffsS1d21sS2d2.1sSnd2g/n g12BSR= b

42、etween-laboratories reproducibility, expressed as standard deviation:SR5 fSr21SL2g12where SL= standard deviation of laboratory means.Cr = within-laboratory critical interval between tow test results = 2.8 Sr.DR = between-laboratories critical interval between tow test results = 2.8 SR.D4475 02 (2016

43、)3the same material, obtained by different operators using differ-ent equipment in different laboratories.13.3 Any judgement in accordance with 13.2.1 or 13.2.2would have an approximate 95 % (0.95) probability of beingcorrect.13.4 There are no recognized standards by which to esti-mate bias of this

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