ASTM_D_3983_-_98_2011.pdf

Designation:D398398(Reapproved 2011)Standard Test Method forMeasuring Strength and Shear Modulus of NonrigidAdhesives by the Thick-Adherend Tensile-Lap Specimen1This standard is issued under the fixed designation D3983;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 a method of measuring theshear modulus and rupture stress in shear of adhesives inbonded joints.The method employs lap-shear specimens withwood,metal,or composite adherends,with adhesives havingshear moduli ranging up to 700 MPa(100 000 psi).This testmethod is suitable generally for joints in which the ratio ofadherend tensile modulus to adhesive shear modulus is greaterthan 300 to 1.It is not suitable for adhesives that have a highshear modulus in the cured state and that also require elimina-tion of volatile constituents during cure.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.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:2D143 Test Methods for Small Clear Specimens of TimberD905 Test Method for Strength Properties of AdhesiveBonds in Shear by Compression LoadingD907 Terminology of AdhesivesD1151 Practice for Effect of Moisture and Temperature onAdhesive BondsD2651 Guide for Preparation of Metal Surfaces forAdhesiveBondingE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE104 Practice for Maintaining Constant Relative Humidityby Means of Aqueous SolutionsE229 Test Method for Shear Strength and Shear Modulus ofStructural Adhesives(Withdrawn 2003)33.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method,referto Terminologies E6 and D907.3.1.2 initial tangent modulus,nthe slope of the stress-strain curve at the origin.3.1.3 nominal stress,nthe stress at a point calculated onthe net cross section by simple elastic theory without takinginto account the effect on the stress produced by discontinuitiessuch as holes,grooves,fillets,etc.3.1.4 normal stress,nthe stress component perpendicularto a plane on which the forces act,that is,the plane of thebondline.3.1.5 proportional limit,nthe maximum stress that amaterial is capable of sustaining without significant deviationfrom proportionality of stress to strain.3.1.6 secant modulus,nthe slope of the secant drawn fromthe origin to any specified point on the stress-strain curve.3.1.6.1 DiscussionModulus is expressed in force per unitarea(MPa,lb/in.2,etc.).3.1.7 shear modulus,nthe ratio of shear stress to corre-sponding shear strain below the proportional limit.(Comparesecant modulus.)3.1.7.1 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.3.1.8 shear strain,nthe tangent of the angular change,dueto force,between two lines originally perpendicular to eachother through a point in the body.3.1.8.1 DiscussionShear strain equals adherend slip/adhesive layer thickness.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 D3983 98(2004).DOI:10.1520/D3983-98R11.2For 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 3.1.9 shear strength,nin an adhesive joint,the maximumaverage stress when a force is applied parallel to the joint.3.1.9.1 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.3.1.10 shear stress,nthe stress component tangential tothe plane of which the forces act,that is,the plane of thebondline.3.1.10.1 DiscussionNominal shear stress equals load/bond area.3.1.11 strain,nthe unit change due to force,in the size orshape of a body r