1、Designation: D 4475 02Standard 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 adoption or, in the
2、 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. Scope *1.1 This test method covers the determination of the appar-ent horizontal shear strength
3、 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 4.1).1.3 The v
4、alues stated in SI units are to be regarded as thestandard.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 applica-bi
5、lity of regulatory limitations prior to use.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:D 618 Practice for Conditioning Plastics for Testing2E 4 Practices for Force Verification of Testing Machines3E 691 Practice for Conducting an Interlaboratory St
6、udy toDetermine the Precision of a Test Method43. 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 thesupp
7、ort 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 applicable to
8、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 recommended t
9、hat 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 crossheadmotion,
10、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 10, 2002. Published May 2002. Originallypublish
11、ed as D 4475 85. Last previous edition D 4475 96.2Annual Book of ASTM Standards, Vol 08.01.3Annual Book of ASTM Standards, Vol 03.01.4Annual Book of ASTM Standards, Vol 14.02.FIG. 1 Test Assembly1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr
12、 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 rate used. The accuracy ofthe testing machine shall be verified in acco
13、rdance withPractices E 4.5.2 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 su
14、pport 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 thediameter of the test specimen to an incremental discriminationof at least
15、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 SpecimensThe number of test specimens isoptional. However, a minimum o
16、f 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 test, in accordance with Procedure A ofPractice D 618 for those tests
17、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. However, temperature controlto 22.2 6 5.6C (72 6 10F) is recommended fo
18、r 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 tolerances shall be 61C(61.8F) and 62 % relative humidity.7.3 Preconditioning
19、 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 (0.05 in.)/min.NOTE 2The test time should be recorded, and, if the test ta
20、kes 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. Procedure9.1 Before conditioning or testing, measure the diameter ofeach specimen
21、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. Adjustthe side supports to the span previously determined. Suggestedspan-
22、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 span-to-specimen diameter ratio in most materials. Whenwriting specificat
23、ions, 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 mechanism). At times,when testing pultruded rods in various environments
24、, 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 also useful to record theposition of the shear plane relative to the spe
25、cimen 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 4475210. Retest10.1 Values for properties at break shall not be calculatedfor any specimen that breaks at some obvious, fortuitous flaw,unless
26、 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 retest shallbe made. However, some of the specimens may not show adistinct failu
27、re 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 reduction or suddenchange in slope of the load-deflection curve.11. Calculations11.1
28、 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 Series of TestsCalculatethe arithmetic mean of all values obtained to three sign
29、ificantfigures 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 deviation,X = value of a single observation,n = number of observations, andX= ari
30、thmetic 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 previoushistory,12.1.2 Fabrication procedure,12.1.3 Diameter of specimen,12.1.4 Conditioning p
31、rocedure 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 horizontal shear strength of each speci-men, average value, and standard deviation,12.
32、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 Bias513.1 Table 1 is based on a round robin conducted in 1984 inaccordance with Practice E 691, involving three materialstested by eleven
33、 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 determinations. Each labo-ratory obtained two test results for each material. Tests wereco
34、nducted at room temperature and 150F.NOTE 4Caution: The explanation of 9r9 and 9R9 in 13.2.1 and 13.2.2are only intended to present a meaningful way of considering theapproximate precision of this test method. The data in Table 1 should notbe applied to acceptance or rejection of materials, as these
35、 data apply onlyto the materials tested in the round robin and are unlikely to be rigorouslyrepresentative of other lots, formulations, conditions, materials, or labo-ratories. Users of this test method should apply the principles outlined inPractice E 691 to generate data specific to their material
36、s and laboratory(or between specific laboratories). The principles of 13.2-13.2.2 wouldthen be valid for such data.13.2 Concept of 9r9 and 9R9 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 res
37、ult, then:13.2.1 Repeatability:Two results obtained within one laboratory shall be judgednot equivalent if they differ by more than the 9r9 value for thatmaterial. 9r9 is the interval representing the critical differencebetween two test results for the same material, obtained by thesame operator usi
38、ng 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 9R9 valuefor that material. 9R9 is the interval representing the criticaldifference between two test re
39、sults for the same material,obtained by different operators using different equipment indifferent laboratories.5Supporting data are available at ASTM Headquarters. Request RR: D20-1118.TABLE 1 Precision StatementShear Strength, 103psiRoom TemperatureValues in the units of psiMaterialRodDiameterMean
40、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 0.165 0.415 0.467 1.17Polyester 1.20 in. 6.83 0.111 0.412 0.314 1.17
41、ASr= within laboratory standard deviation for the indicated material. 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 deviatio
42、n:SR5 Sr21 SL2#12where SL= standard deviation of laboratory means.Cr = within-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 4475313.3 Any judgement in accordance with 13.2.1 or 13.2.2would have an ap
43、proximate 95% (0.95) probability of beingcorrect.13.4 There are no recognized standards by which to esti-mate bias of this method.SUMMARY OF CHANGESThis section identifies the location of selected changes to this test method. For the convenience of the user,Committee D20 has highlighted those change
44、s that may impact the use of this test method. This section may alsoinclude descriptions of the changes or reasons for the changes, or both.D 4475 02:(1) The precision and bias statement was revised in format in2001.ASTM International takes no position respecting the validity of any patent rights as
45、serted 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
46、by the 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 rec
47、eive careful 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 Int
48、ernational, 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 44754
