ASTM_D_2557_-_98_2010e1.pdf

Designation:D255798(Reapproved 2010)1Standard Test Method forTensile-Shear Strength of Adhesives in the SubzeroTemperature Range from 267.8 to 55C(450 to 67F)1This standard is issued under the fixed designation D2557;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.1NOTESection 8.6.4 was editorially corrected in October 2010.1.Scope1.1 This test method covers the determination of the com-parative shear strength of adhesives for bonding metals whentested on a standard specimen and under specified conditions ofpreparation and testing at extreme subzero temperatures.1.2 This test method is applicable to the temperature rangefrom-267.8 to-55C(-450 to-67F).1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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.Specific precau-tions are given in 8.3.2.Referenced Documents2.1 ASTM Standards:2A167 Specification for Stainless and Heat-ResistingChromium-Nickel Steel Plate,Sheet,and Strip(With-drawn 2014)3B209 Specification for Aluminum and Aluminum-AlloySheet and PlateB265 Specification for Titanium and Titanium Alloy Strip,Sheet,and PlateD907 Terminology of AdhesivesD1002 Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Ten-sion Loading(Metal-to-Metal)D4896 Guide for Use of Adhesive-Bonded Single Lap-JointSpecimen Test Results3.Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D907.4.Significance and Use4.1 This test method may be used as an accelerated screen-ing test for assessing the strength properties of adhesives andadhesive joints at subzero temperatures.This test method mayalso be used to determine the effects of various surfacepreparations,substrates,or adhesive systems on the durabilityof the adhesive joints at subzero temperatures.4.2 Tensile shear strengths of various adhesives,surfacepreparations,and substrates may be compared by using this testmethod for uniform sets of conditions.To assess the overalltensile shear strength of a given adhesive,surface preparation,and substrate should be tested under a range of stress andtemperatures.For a specific end use,the needed strengthproperties using only one set of test conditions may beobtained.4.3 The misuse of strength values obtained from this testmethod as design-allowable stress values for structural jointscould lead to product failure,property damage,and humaninjury.4.3.1 The apparent shear strength of an adhesive obtainedfrom a given small single-lap specimen may differ from thatobtained from a joint made with different adherends or by adifferent bonding process.The normal variation of temperatureand moisture in the service environment causes the adherendsand the adhesive to swell or shrink.The adherends andadhesive are likely to have different thermal and moisturecoefficients of expansion.Even in small specimens,short-termenvironment changes can induce internal stresses of chemicalchanges in the adhesive that permanently affect the apparentstrength and other properties of the adhesive.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.80 on MetalBonding Adhesives.Current edition approved Oct.1,2010.Published October 2010.Originallyapproved in 1966.Last previous edition approved in 2004 as D2557 98(2004).DOI:10.1520/D2557-98R10E01.2For 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 4.3.2 The problem of predicting joint behavior in a chang-ing environment is even more difficult if a different type ofadherend is used in a larger structural joint than was used in thesmall specimen.4.3.3 The apparent shear strength measured with a single-lap specimen is not suitable for determining design-allowablestresses for designing structural joints that differ in any mannerfrom the joints tested without thorough analysis and under-standing of the joint and adhesive behaviors.4.3.4 Single-lap tests may be used for comparing andselecting adhesives or bonding processes for susceptibility tofatigue and environmental changes,but such comparisons mustbe made with