1、Designation: D 3846 02Standard Test Method forIn-Plane Shear Strength of Reinforced Plastics1This standard is issued under the fixed designation D 3846; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope *1.1 This test method covers the determination of the in-
3、plane shear strength of reinforced thermosetting plastics in flatsheet form in thicknesses ranging from 2.54 to 6.60 mm (0.100to 0.260 in.).1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport
4、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.NOTE 1This standard has no known ISO equivalent.2.
5、 Referenced Documents2.1 ASTM Standards:D 618 Practice for Conditioning Plastics for Testing2D 695 Test Method for Compressive Properties of RigidPlastics2D 2344 Test Method for Short-Beam Strength of PolymerMatrix Composite Materials and Their Laminates3E 4 Practices for Force Verification of Testi
6、ng Machines4E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method53. Terminology3.1 Definitions:3.1.1 in-plane shear strengththe shear strength at rupturein which the plane of fracture is located along the longitudinalaxis of the specimen between two centr
7、ally located notchesmachined halfway through its thickness on opposing faces.4. Summary of Test Method4.1 In-plane shear strength, as determined by this testmethod, is measured by applying a compressive load to anotched specimen of uniform width. The specimen is loadededgewise in a supporting jig of
8、 the same description as thatreferenced in Test Method D 695 for testing thin specimens. Aschematic of the specimen used for this test and the supportingjig is shown in Fig. 1. Failure of the specimen occurs in shearbetween two centrally located notches machined halfwaythrough its thickness and spac
9、ed a fixed distance apart onopposing faces.5. Significance and Use5.1 Shear tests of various kinds are widely used in thereinforced plastics industry to assess the strength of thereinforcement-to-resin bond in polyester-, vinyl ester-, andepoxy-resin composites. In addition to their importance for t
10、hegeneration of data for research and development, qualitycontrol, and specification purposes, such tests are of fundamen-tal value to the fibrous reinforcement industry, since they canbe used to assess the potential of new sizing systems for thesurface treatment of glass fibers.5.2 This test method
11、 is useful for establishing the shearstrength of laminates or other reinforced plastics havingrandomly dispersed fiber reinforcement. While the test alsolends itself to parallel-fiber reinforced plastics, it has beendesigned to accommodate nonparallel-fiber reinforced materi-als that cannot be teste
12、d satisfactorily by the short-beamprocedure described in Test Method D 2344.6. Apparatus6.1 Testing MachineAny suitable testing machine capableof control of constant-rate-of-crosshead movement and com-prising essentially the following:6.1.1 Drive MechanismA drive mechanism for impartingto the movabl
13、e member a uniform, controlled velocity withrespect to the stationary member, as required in 10.3.6.1.2 Load IndicatorA load-indicating mechanism ca-pable of showing the total compressive load carried by the testspecimen. The mechanism shall be essentially free of inertiallag at the specified rate o
14、f testing and shall indicate the load1This 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. Originallypublished as D 3846 7
15、9. Last previous edition D 3846 94.2Annual Book of ASTM Standards, Vol 08.01.3Annual Book of ASTM Standards, Vol 15.03.4Annual Book of ASTM Standards, Vol 03.01.5Annual Book of ASTM Standards, Vol 14.02.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International,
16、100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.with an accuracy of 61 % of the maximum indicated value ofthe test (load). The accuracy of the testing machine shall beverified at least once a year in accordance with Practices E 4.6.1.3 Compression ToolA compressio
17、n tool for applyingthe load to the test specimen, such as those shown in Figs. 1and 2 of Test Method D 695.6.1.4 Supporting JigA supporting jig, shown schemati-cally in Fig. 1, and conforming to the dimensions of that shownin Fig. 4 of Test Method D 695.6.1.5 MicrometersSuitable micrometers, reading
18、 to 0.025mm (0.001 in.) for measuring the width and thickness of thespecimens, as well as the depth of, and distance between, thenotches.6.1.6 Torque WrenchA suitable torque wrench for tight-ening the nuts of the supporting jig of 6.1.4 to the torqueprescribed in 10.2.7. Test Specimens7.1 Configurat
19、ionTest specimens shall conform to theshape and dimensions given in Fig. 1. The edges of thespecimens shall be smooth, but not rounded or beveled.7.2 PreparationTwo parallel cuts, one on each oppositeface of the specimen and 6.4 mm (0.25 in.) apart, shall besawed across the entire width of the speci
20、men and centrallylocated along its length. The width and depth of notch shallconform to the dimensions shown in Fig. 1. For laminatedmaterials, the notch shall be of sufficient depth to sever thecenter ply of the reinforcement, located midway between thetwo faces of the laminate.7.3 NumberFive speci
21、mens shall be tested wheneverisotropic materials are under test. When testing material that issuspected or known to be anisotropic, ten specimens (fivenormal to and five parallel with the principal axis of anisot-ropy) shall be tested.8. Conditioning8.1 ConditioningCondition the test specimens at 23
22、 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 where conditioning is required.In case of disagreement, the tolerances shall be 61C (61.8F)and 62 % relative humidity.8.2 Test ConditionsConduct test
23、s 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 cases ofdisagreement, the tolerances shall be 61C (61.8F) and62 % relative humidity.9. Speed of Testing9.1 Speed of testing shall be the relative rate of motion ofthe grips
24、or test fixtures during the test. Rate of motion of thedriven grip or fixture when the machine is running idle may beused if it can be shown that the resulting speed of testing iswithin the limits of variation allowed.9.2 The standard speed of testing shall be 1.36 0.3 mm/min(0.050 6 0.010 in./min).
25、10. Procedure10.1 Measure the width of the specimen between thenotches to the nearest 0.025 mm (0.001 in.).10.2 Mount the specimen in the supporting jig (Fig. 1) sothat it is flush with the base and centered. Tighten the nuts ofthe jig with the torque wrench of 6.1.6 to a torque of0.113 + 0.000, 0.0
26、28 Nm (1.00 + 0.00, 0.25 lbfin.). Placethe assembly in the compression tool described in 6.1.3.10.3 Set the speed control at 1.3 mm/min (0.050 in./min)and start the machine.10.4 Record the maximum load carried by the specimenduring the test. (Usually this will be the load at the moment ofrupture.)10
27、.5 Determine the length of the failed (sheared) area to thenearest 0.025 mm (0.001 in.) by measurement of this surfacewith respect to either half of the ruptured specimen. Thistechnique affords the most accurate determination of the lengthof the sheared plane defined by the separation of the notches
28、machined in the specimen.11. Calculation11.1 In-Plane Shear StrengthCalculate the in-plane shearstrength by dividing the maximum shear load carried by thespecimen during the test by the product of the width of thespecimen (see 10.1) and the length of the failed area, asdetermined in 10.5. Express th
29、e result in megapascals orpounds-force per square inch and report it to three significantfigures.12. Report12.1 Report the following information:12.1.1 Complete identification of the material tested, includ-ing type, source, manufacturers code number, form, principaldimensions, previous history, etc
30、.,12.1.2 Method of preparing test specimens,12.1.3 Conditioning procedure used,FIG. 1 Specimen and Loading Jig for In-Plane Shear TestD 3846212.1.4 Atmospheric conditions in test room,12.1.5 Number of specimens tested,12.1.6 A brief description of the type of testing machineused, and the date on whi
31、ch it was last verified (see 6.1.2) andby whom,12.1.7 In-plane shear strength, average value, and standarddeviation, and12.1.8 Date of test.13. Precision and Bias13.1 Table 1 is based on a round robin conducted in 2001 inaccordance with Practice E 691, involving two materials testedby five laborator
32、ies. For each material, all the samples wereprepared 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 four test results for each material.NOTE 2Caution: The exp
33、lanation 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 data apply onlyto the materials tested in the round robin
34、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 materials and laboratory(or between specific laboratories). The pri
35、nciples 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 five specimens for eachtest result, then:13.2.1 Repeatability:Two results obtained within
36、 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 using the same equipment on the same day in thesame laborator
37、y.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 results for the same material,obtained by different operator
38、s using different equipment indifferent 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 method.14. Keywords14.1 compressive shear; in-plane sh
39、ear; plastics; reinforcedplasticsSUMMARY OF CHANGESThis section identifies the location of selected changes to this test method. For the convenience of the user,Committee D20 has highlighted those changes that may impact the use of this test method. This section may alsoinclude descriptions of the c
40、hanges or reasons for the changes, or both.D 3846 02:(1) The precision and bias statement was revised in format in2001.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressl
41、y 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 responsible technical committee and must be reviewed every five years andif not revised, e
42、ither 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 careful consideration at a meeting of theresponsible technical committee, which you may atte
43、nd. 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. I
44、ndividual 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).TABLE 1 Precision Statement for In-Plane ShearMaterial Mean Sr
45、ASRBrCRDVinyl Ester 3042 775 1241 2171 3474Polyester 2898 710 1296 1989 3631ASr= 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
46、#12BSR= between-laboratories reproducibility, expressed as standard deviation: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 38463
