1、Designation:D271919Standard Test Methods forWood Structural Panels in Shear Through-the-Thickness1This standard is issued under the fixed designation D2719;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A n
2、umber in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods determine the shear through-the-thickness properties of wood structural panels associated withshear distortion of the maj
3、or axis.Wood structural panels in useinclude plywood,oriented strand board,and composites ofveneer and of wood-based layers.Three test methods areincluded which differ somewhat in their application:Test MethodSectionA.Small Panel Shear Test5B.Large Panel Shear Test6C.Two-Rail Shear Test7The choice o
4、f test method will be determined in part by thepurpose of the tests,characteristics of test material,andequipment availability.In general,Test Method B or C for largespecimens is preferred when equipment,amount of testmaterial,and experimental plan permit.1.1.1 Test Method A:Small Panel Shear TestTh
5、is testmethod is suitable for testing small samples of uniformmaterial including investigations of the effects of grain direc-tion or orientation and of many raw materials and manufactur-ing process variables which influence shear properties uni-formly throughout the specimen.The test method is unsu
6、itedfor determining effects of grade and manufacturing featuressuch as density variations,knots,and core gaps within thespecimen.1.1.2 Test Method B:Large Panel Shear TestThis testmethod is regarded as giving the most accurate modulus ofrigidity and is therefore recommended for elastic tests ofmater
7、ials to be used in stress analysis studies of test structures.This test method also yields excellent shear strength values forclear material.However,in spite of the large size of thespecimen,failures generally occur only in narrow zones at theperimeter of the test area.This characteristic,a result o
8、f theheavy perimeter framing,causes this test method to be gener-ally unsuited for determining grade and manufacturing effectssuch as density variations,core gaps,and knots that are notuniformly distributed throughout the panel.Generally,only incases where effects of these factors under conditions o
9、f heavyperimeter framing are desired,should the test method beapplied.1.1.3 Test Method C:Two-Rail Shear TestThis testmethod is applicable to a wide variety of materials andproblems.The specimen fabrication and test procedures aresomewhat simpler than in Test MethodsAand B.The specimenis free to she
10、ar parallel to its 24-in.(610-mm)length dimensionanywhere within the 8-in.(203-mm)width between rails.Thus,the test method is well suited for determining grade andmanufacturing effects such as core gaps and knots occupyingand affecting small areas.The test method is not so ideallysuited for determin
11、ation of modulus of rigidity,but whenadjusted for strain distribution effects,values approximatingthose obtained by Test Method B result.The test methodsimulates effects of heavy framing when expected planes ofweakness are oriented perpendicular to rails and no framing atall when parallel to rails.N
12、OTE1Asmaller scale version based on the principles of this two-railshear method is contained in Test Methods D1037 Section 27.The resultsfrom Test Methods D1037 Section 27 may not be equivalent to the resultsfrom Test Methods D2719 Method C.1.2 Significant differences,moderate to small in magnitude,
13、among the three test methods have been found to exist whenthese test methods are applied to plywood of clear straight-grained veneers.Therefore,when comparisons are madeamong test results,it is recommended that the same testmethod be used throughout.1.3 This standard does not purport to address all
14、of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor
15、-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.1These test methods are under the
16、jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.03 on Panel Products.Current edition approved April 1,2019.Published June 2019.Originallyapproved in 1969.Last previous edition approved in 2013 as D2719 13.DOI:10.1520/D2719-19.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 standardization
