ASTM_D_4027_-_98_2011.pdf

Designation:D402798(Reapproved 2011)Standard Test Method forMeasuring Shear Properties of Structural Adhesives by theModified-Rail Test1This standard is issued under the fixed designation D4027;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 describes equipment and procedures tomeasure the shear modulus and shear strength of adhesivelayers between rigid adherends.The equipment may also beused for determining the adhesives shear creep compliance,the effects of strain history such as cyclic loading upon shearproperties,and a failure criteria for biaxial stress conditionssuch as shear plus tension and shear plus compression.21.2 High-density wood shall be the preferred substrate.Thepractical upper limit on the shear modulus that can bemeasured is determined by the shear modulus of the adherendsand by the strain measuring device.Thus,the practical limit ofadhesive shear modulus that can be measured using high-density wood adherends is about 690 MPa(1 105psi).NOTE1Wood-base composites,metal,plastic,reinforced plastics,andother common construction materials may also be used for adherends.1.3 The range of specimen dimensions that can be testedare:width 1.59 to 12.70 mm(0.0625 to 0.500 in.),length 102to 203 mm(4 to 8 in.),and adherend thickness 13 to 25 mm(0.50 to 1.00 in.).The standard specimen dimensions shall be:width 3.18 mm(0.125 in.),length 203 mm(8 in.),andadherend thickness 19 mm(0.75 in.).Bondline thicknessesfrom 0.15 to 3.18 mm(0.006 to 0.125 in.)may be tested.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 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:3D905 Test Method for Strength Properties of AdhesiveBonds in Shear by Compression LoadingD907 Terminology of AdhesivesD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based MaterialsE83 Practice for Verification and Classification of Exten-someter SystemsE229 Test Method for Shear Strength and Shear Modulus ofStructural Adhesives(Withdrawn 2003)43.Terminology3.1 Definitions:3.1.1 Many terms in this test method are defined in Termi-nology D907.3.1.2 shear modulus,nthe ratio of shear stress to corre-sponding shear strain below the proportional limit.(Comparesecant modulus.)3.1.2.1 DiscussionThe term shear modulus is generallyreserved for materials that exhibit linear elastic behavior overmost of their stress-strain diagram.Many adhesives exhibitcurvilinear or nonelastic behavior,or both,in which case someother term,such as secant modulus,may be substituted.3.1.3 shear strain,nthe tangent of the angular change,dueto force between two lines originally perpendicular to eachother through a point in the body.3.1.3.1 DiscussionShear strain equals adherend slip/adhesive layer thickness.3.1.4 shear strength,nin an adhesive joint,the maximumaverage stress when a force is applied parallel to the joint.3.1.4.1 DiscussionIn most adhesive test methods,theshear strength is actually the maximum average stress at failureof the specimen,not necessarily the true maximum stress in thematerial.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.70 on ConstructionAdhesives.Current edition approved Jan.1,2011.Published January 2011.Originallyapproved in 1981.Last previous edition approved in 2004 as D4027 98(2004).DOI:10.1520/D4027-98R11.2Kreuger,G.P.,“Tests for the Shear Properties of Adhesives in Adherend-Adhesive Assemblies,”Unpublished report.Michigan Technological Institute,Houghton,MI.3For 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.4The 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 3.2 Definitions of Terms Specific to This Standard:3.2.1 load,nthe force applied to the specimen at anygiven time.3.2.2 load-slip diagram,na diagram in which correspond-ing values of load and slip are plotted against each other.Values of load are usually plotted as ordinates and values ofslip as abscissas.3.2.3 normal stress,nthe stress component perpendicularto a plane on which the forces act,that is,perpendicular to theplane of the bondline.3.2.4 propor