ASTM_D_4475_-_21.pdf

Designation:D447521Standard 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.Scope*1.1 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 5.1).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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE1There is no known ISO equivalent to this standard.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsE4 Practices for Force Verification of Testing MachinesE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Terms used in this standard are defined in accordancewith Terminology D883,unless otherwise specified.For termsrelating to precision and bias and associated issues,the termsused in this standard are defined in accordance with Terminol-ogy E456.4.Summary of Test Method4.1 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.2.4.2 The specimen is deflected until a shear failure occurs atthe midplane of the horizontally supported rod.Adjust the spanto achieve the required shear mode of failure.NOTE2Using a span of three times the diameter of rod typicallycauses shear failure.If needed,that span can be adjusted up to six timesthe diameter of the rod.5.Significance and Use5.1 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 is not intended for designpurposes,but allowed to be utilized for comparative testing ofcomposite materials,if all failures are in horizontal shear.5.2 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.6.Apparatus6.1 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 PracticesE4.1This 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 July 1,2021.Published July 2021.Originally approvedin 1985.Last previous edition approved in 2016 as D4475-02(2016).DOI:10.1520/D4475-21.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.16.2 Loading Nose and SupportsShown in Fig.2 and Fig.3.The loading nose shall be a