1、Designation:D468098(Reapproved 2017)Standard Test Method forCreep and Time to Failure of Adhesives in Static Shear byCompression Loading(Wood-to-Wood)1This standard is issued under the fixed designation D4680;the number immediately following the designation indicates the year oforiginal adoption or,
2、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 time-dependent properties of structural ad
3、hesives in wood-to-woodbonds when specimens are subjected to shearing stresses atvarious levels of static load,constant temperature,and relativehumidity.Apparatus and procedures are provided for directmeasurement of time-dependent shear deformation(creep)andtime to failure of adhesive bonds under st
4、atic load.Guidelinesfor selecting test conditions,methods for calculating creep rate,creep strain,creep modulus,and extrapolation of time tofailure,are given along with methods of presenting these data.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parent
5、heses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 sa
6、fety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 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
7、Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.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 Loadi
8、ngD907 Terminology of AdhesivesD2016 Methods of Test for Moisture Content of Wood(Withdrawn 1987)32.2 ASTM Adjuncts:Compression-Shear Creep Test Apparatus43.Terminology3.1 Definitions:3.1.1 Many terms in these test methods are defined inTerminology D907.3.1.2 creep,nthe dimensional change with time
9、of amaterial under load,following the initial instantaneous elasticor rapid deformation.Creep at room temperature is sometimescalled cold flow.3.1.3 creep modulus,nthe ratio of initial applied stress tocreep strain.3.1.4 creep strain,nthe total strain,at any given time,produced by the applied stress
10、 during a creep test.3.1.4.1 DiscussionIn this test method,creep strain iscalculated by dividing displacement at any given time by theestimated apparent thickness of the adhesive bondline.3.1.5 rate of creep,nthe slope of the creep-time curve ata given time.3.1.6 shear stress,nthe stress component t
11、angential to theplane on which the forces act,that is,in the plane of the bondline.3.1.7 strain,nthe unit change,due to stress,in the size orshape of a body referred to its original size or shape.3.1.8 stress,nthe force exerted per unit area at a pointwithin the plane.4.Significance and Use4.1 Creep
12、 data that are obtained over a relatively shortperiod of time in this test method can provide a measure of anadhesive bonds ability to withstand static loading in shear overa relatively long period of time.Creep measurements are made1This test method is under the jurisdiction of ASTM Committee D14 o
13、nAdhesives and is the direct responsibility of Subcommittee D14.30 on WoodAdhesives.Current edition approved Aug.1,2017.Published August 2017.Originallyapproved in 1987.Last previous edition approved in 2011 as D4680 98(2011).DOI:10.1520/D4680-98R17.2For referenced ASTM standards,visit the ASTM webs
14、ite,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.4Available from ASTM Internation
15、al Headquarters.Order Adjunct No.ADJD4680.Original adjunct produced in 1987.Copyright 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 standardizatio
16、n 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.1 over a range of expected service conditions,including level ofstress,temperature,relative humidity,and duration of load.Creep rate,creep strain,and creep modulus are calculated atthe various service conditions.4.2 Creep data can be used to(1)predict performance of anadhesive under long-term loading,
