1、Designation:D271913Standard Test Methods forStructural 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 number
2、 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 structural panels associated with sheardistortion of the major axis.St
3、ructural panels in use includeplywood,oriented strand board,and composites of veneer andof wood based layers.Three test methods are included whichdiffer somewhat in their application:Test MethodSectionA.Small Panel Shear Test5B.Large Panel Shear Test6C.Two Rail Shear Test7The choice of test method w
4、ill 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 TestThis testmethod i
5、s 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 unsuitedfor determi
6、ning 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 ofmaterials to be used
7、 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 of theheavy peri
8、meter 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 of heavyperimete
9、r framing are desired,should the test method beapplied.1.1.3 Test Method C:Two-Rail Shear Test This 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 shear parallel to
10、 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 determination of modul
11、us 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.NOTE1Asmaller s
12、cale 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,among the thre
13、e 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 of thesafety c
14、oncerns,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:2D1037 Test Methods for Evaluating Proper
15、ties of Wood-Base Fiber and Particle Panel Materials1These test methods are under the jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.03 on Panel Products.Current edition approved Oct.1,2013.Published October 2013.Originallyapproved in 1969.Last previo
16、us edition approved in 2007 as D2719 89(2007).DOI:10.1520/D2719-13.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 D2395 Test Methods for Density and Specific Gravity(Rela-tive Density)of Wood and Wood-Ba
