ASTM_D_4475_-_02_2008.pdf

Designation:D447502(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 D4475;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 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 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(see 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 applica-bility of regulatory limitations prior to use.NOTE1There is no similar or equivalent ISO 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 Interlaboratory 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 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 applicable 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 recommended 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 motion,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 PracticesE4.5.2 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 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 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 of five specimens is required 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 March 1,2008.Published March 2008.Originallyapproved in 1985.Last previous edition approved in 2002 as D4475-02.DOI:10.1520/D4475-02R08.2For 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 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 States1 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 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