ASTM D4475-2002(2008) Standard Test Method for Apparent Horizontal Shear Strength of Pultruded Reinforced Plastic Rods By the Short-Beam Method《用短梁法测定挤拉制增强塑料棒表观水平剪切强度的标准试验方法》.pdf

《ASTM D4475-2002(2008) Standard Test Method for Apparent Horizontal Shear Strength of Pultruded Reinforced Plastic Rods By the Short-Beam Method《用短梁法测定挤拉制增强塑料棒表观水平剪切强度的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM D4475-2002(2008) Standard Test Method for Apparent Horizontal Shear Strength of Pultruded Reinforced Plastic Rods By the Short-Beam Method《用短梁法测定挤拉制增强塑料棒表观水平剪切强度的标准试验方法》.pdf（4页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: D 4475 02 (Reapproved 2008)Standard Test Method forApparent Horizontal Shear Strength of Pultruded ReinforcedPlastic Rods By the Short-Beam Method1This standard is issued under the fixed designation D 4475; the number immediately following the designation indicates the year oforiginal a

2、doption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the appar-ent horizonta

3、l shear 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 (se

4、e 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 th

5、e applica-bility of regulatory limitations prior to use.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingE4 Practices for Force Verification of Testing MachinesE 691 Practice for Conducting an Interlab

6、oratory 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 alon

7、g 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 appli

8、cable 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 reco

9、mmended 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 MachineA properly calibrated testing ma-chine that can be operated at a constant rate of crosshea

10、dmotion, and in which the error in the load measuring system1This 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 March 1, 2008. Published March 2008. Origina

11、llyapproved in 1985. Last previous edition approved in 2002 as D4475 - 02.2For 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 standards Document Summary page onthe

12、ASTM website.FIG. 1 Test Assembly1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.shall not exceed 61 % of the maximum load expected to bemeasured. The load-indicating mechanism shall be essentiallyfree of inertia lag at the crosshead

13、 rate used. The accuracy ofthe testing machine shall be verified in accordance withPractices 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

14、 always have a plus tolerance andzero negative tolerance. The bottom support shall be adjustableto 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 thedia

15、meter of the test specimen to an incremental discriminationof at least 0.025 mm (0.001 in.) shall 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

16、 SpecimensThe number of test specimens isoptional. However, a minimum of five specimens is required toobtain a satisfactory average and standard deviation.7. Conditioning7.1 ConditioningCondition the test specimens at 23 62C (73.4 6 3.6F) and 50 6 5 % relative humidity for not lessthan 40 h prior to

17、 test, in accordance with Procedure A ofPractice D 618 for those tests where conditioning is required.In cases of disagreement, the tolerances shall be 61C(61.8F) and 62 % relative humidity. These conditions arerecommended for research and development trials, but notnecessarily for quality control.

18、However, temperature controlto 22.2 6 5.6C (72 6 10F) is recommended for qualitycontrol.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 otherwise specified in the test meth-ods. In cases of disagreement, the tolera

19、nces 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 of Testing8.1 Test the specimen at a rate of crosshead motion of 1.3mm (0.

20、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 insteps, until the time to complete the test is less than 200 s.9. Procedure9.

21、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 midpoint is centeredand its long axis is perpendicular to the loading nose. Ad

22、justthe 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 3Experimental data indicates that shear strength is a functionof support sp

23、an-to-specimen diameter ratio in most materials. Whenwriting specifications, both the specimen diameter and the span-to-diameter ratio should be specified.9.3 Apply the load to the specimen at the specified cross-head rate. Record the load to break for each specimen(maximum load on load-indicating m

24、echanism). 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 type of break (shear or tensile) thatoccurs. For research purposes, it is a

25、lso useful to record theposition of the shear plane relative to the specimen center line.FIG. 2 Span Configuration for 3D Span. Span. May Also Be 4D,5D, or 6D, as Required to Achieve Shear Mode of FailureFIG. 3 Anvil DimensionsD 4475 02 (2008)210. Retest10.1 Values for properties at break shall not

26、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. Should a specimen fail in a manner other thanhorizontal shear, the value shall be discarded and a

27、 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 deflectometer, be used to help determine the fracturepoint. This is normally the first major load red

28、uction 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 = breaking load, N, (or lbf), andd = diameter of specimen, m, (or in.).11.2 Arithmetic Mean for Each

29、 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 and report to two significant figures:s 5 =(X22 nX2!/n 2 1! (2)where:s = estimated standard

30、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 of the material tested, includ-ing type, source, form, principle dimensions, and previoushisto

31、ry,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,12.1.8 Span length,12.1.9 Length of specimens,12.1.10 Type of failure,12.1.11 Apparent horiz

32、ontal shear strength of each speci-men, 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, and12.1.14 Date of test.13. Precision and Bias313.1 Table 1 is based on a round robin conducted in

33、 1984 inaccordance with Practice E 691, involving three materialstested by eleven laboratories. For each material, all the sampleswere prepared at one source, but the individual specimens wereprepared at the laboratories which tested them. Each test resultwas the average of five individual determina

34、tions. 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 meaningful way of considering theapproximate precision of this test method. The data in Tabl

35、e 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, conditions, materials, or laboratories. Users ofthis test method should apply the principle

36、s outlined in PracticeE 691 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 “R” in Table 1If Srand SRhavebeen calculated from a large enough body of data, and for t

37、estresults that were averages from testing two specimens for eachtest result, then:13.2.1 Repeatability:Two results obtained within one laboratory shall be judgednot equivalent if they differ by more than the “r” value for thatmaterial. “r” is the interval representing the critical differencebetween

38、 two test results for the same material, obtained by thesame operator using the same equipment on the same day in thesame laboratory.13.2.2 Reproducibility:Two test results obtained by different laboratories shall bejudged not equivalent if they differ by more than the “R” valuefor that material. “R

39、” is the interval representing the critical3Supporting data are available at ASTM Headquarters. Request RR: D20-1118.TABLE 1 Precision StatementShear Strength, 103psiRoom TemperatureValues in the units of psiMaterialRodDiameterMean SrASRBIrCIRDVinyl ester 0.85 in. 10.2 0.236 0.519 0.665 1.47Vinyl es

40、ter 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 0.165 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

41、. It isobtained by pooling the within-laboratory standard deviations of the test results forall of the participating laboratories:Sr5 S1!21 S2!21 Sn!2/n 12BSR= between-laboratories reproducibility, expressed as standard deviation:SR5 Sr21 SL2#12where SL= standard deviation of laboratory means.Cr = w

42、ithin-laboratory critical interval between tow test results = 2.8 3 Sr.DR = between-laboratories critical interval between tow test results = 2.8 3 SR.D 4475 02 (2008)3difference between two test results for the same material,obtained by different operators using different equipment indifferent labo

43、ratories.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 method.ASTM International takes no position respecting the validity of any patent rights asserted

44、 in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the

45、 responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive c

46、areful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Internati

47、onal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4475 02 (2008)4