ASTM_F_1362_-_13.pdf

Designation:F136213Standard Test Method forShear Strength and Shear Modulus of Aerospace GlazingInterlayer Materials1This standard is issued under the fixed designation F1362;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 shearstrength and shear modulus of interlayer materials that arerestrained by relatively high modulus plies in laminatedtransparencies.This test method can be used with single ormultiple plies of the same interlayer materials.1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.3 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.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingE4 Practices for Force Verification of Testing MachinesE229 Test Method for Shear Strength and Shear Modulus ofStructural Adhesives(Withdrawn 2003)3E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodF734 Test Method for Shear Strength of Fusion BondedPolycarbonate Aerospace Glazing Material3.Terminology3.1 Definitions:3.1.1 adherendrelatively higher modulus plies that re-strain interlayer materials.3.1.2 shear modulusthe ratio of the shear stress to thecorresponding shear strain for the initial straight-line portion ofthe curve.3.1.3 shear strengththe maximum shear stress existing inthe interlayer prior to failure.Represents the shear strength ofthe system either as a cohesive or adhesive failure mode.4.Summary of Test Method4.1 Torsional shear forces are applied to the interlayerthrough a circular section that produces a peripherally uniformstress distribution.The maximum stress in the interlayer atfailure represents the apparent shear strength of the interlayer.By measuring the interlayer strain as a function of load,astress-strain curve can be established.The test specimen shouldbe made from the same materials that are to be used inproduction,and production processes should be used whenapplicable.It is also possible to fabricate specimens from thefinished/formed transparency.5.Significance and Use5.1 The basic material properties obtained from this testmethod can be used in the control of the quality of interlayers,inthetheoreticalequationsfordesigninglaminatedtransparencies,and in the evaluation of new interlayers.6.Apparatus6.1 Testing MachinesMachines used for shear testing shallconform with the requirements of Practices E4.The loads usedin determining shear strength shall be within the loading rangeof the testing machine as defined in Practices E4.6.2 Torsional Shear ApparatusThe torsional shear jigshould apply a torsional shear load to the specimen withoutinducing bending,peeling,or transverse shear stresses in thetest section.Loading can be accomplished with torsion-testequipment or by means of a jig that can be used in a universaltesting machine.A jig is shown in Fig.1(see Practice F734)and Figs.2 and 3 show the adaptations required for the variousspecimens.Adequate precautions should be taken to ensure aminimum of frictional loss of torque(as by careful bearingdesign)or to provide a direct measurement of the appliedtorque(as by a load cell),or both,and to prevent the1This test method is under the jurisdiction of ASTM Committee F07 onAerospace and Aircraft and is the direct responsibility of Subcommittee F07.08 onTransparent Enclosures and Materials.Current edition approved Dec.1,2013.Published January 2014.Originallyapproved in 1991.Last previous edition approved in 2009 as F1362 09.DOI:10.1520/F1362-13.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 application of axial forces.Also,take care to take up the slackin the system prior to the start of each test.6.3 Measurement of Angular DisplacementSince the shearstrains of an interlayer will normally be very large,the angulardisplacement should be measured using an angular displace-ment transducer.This transducer can be either internal to thetorsion-test machine or attached to the jig.7.Test Specimens7.1 The specimen shall consist of laminated transparencymaterial machined in such a way as to produce an annu