1、Designation:D271818Standard Test Methods forStructural Panels in Planar Shear(Rolling Shear)1This standard is issued under the fixed designation D2718;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 properties ofstructural panels associated with shear distortion of the planesparallel to the edge planes o
3、f the panels.Both shear strengthand modulus of rigidity may be determined.Primarily,the testsmeasure the planar shear(rolling shear)strength developed inthe plane of the panel.1.2 Structural panels in use include,but are not limited to,structural plywood,oriented strand board(OSB),and compos-ites of
4、 veneer and of wood-based layers.1.3 Two test methods are included:1.3.1 Test Method APlanar shear loaded by plates.1.3.2 Test Method BPlanar shear induced by five-pointbending.1.3.3 The choice of method will be dictated by the purposeof the test and equipment available.1.3.4 Test Method A,Planar Sh
5、ear Loaded by PlatesThistest method uses a rectangular panel section adhered betweensteel plates with protruding knife edges to create load at thepanel faces.This test method has been used to develop shearproperties of plywood and oriented strand board for thepurpose of confirming design values.This
6、 test method does notproduce pure shear,but the specimen length is prescribed sothat the secondary stresses have a minimum effect.The methoddetermines shear strength and modulus of rigidity.1.3.5 Test Method B,Planar Shear Induced by Five-PointBendingPlanar shear stress is induced on the panel while
7、loaded in bending using two continuous spans.This testmethod determines planar shear strength consistent with panelapplications under transverse loading.This test method is ableto determine shear strength at any moisture condition.1.4 This standard does not purport to address all of thesafety concer
8、ns,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.1.5 This international standard was developed in accor-dance with interna
9、tionally 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.2.Referenced Documents2.1 ASTM Standards:2D2395 Test
10、Methods for Density and Specific Gravity(Rela-tive Density)of Wood and Wood-Based MaterialsD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based Materials3.Significance and Use3.1 Planar shear(rolling shear)characteristics of structuralpanels determined by these test met
11、hods are essential for therigorous design of various glued wood-panel structuralcomponents,such as box beams,folded plate roofs,andstressed skin panels.Planar shear also may govern the designat low span-depth ratios encountered in floors subjected to highconcentrated loads,concrete forms at high pou
12、ring pressures,and bulk storage structures.3.2 The modulus of rigidity determined from Test MethodAis a composite of the entire specimen acting as a unit.Forplywood panels for which the ratio between the shear moduliof the plies with grain oriented parallel and perpendicular to theshear forces is kn
13、own,the rolling shear modulus of theperpendicular plies can be calculated.3.3 Veneer produced by slicing or rotary peeling maycontain fine checks or separations parallel to the grain on theknife side of the veneer that are produced as the knife is forcedthrough the wood.These checks are termed“knife
14、 checks”todistinguish them from occasional checks that may be formedon the opposite side of the veneer by forces at the compressionbar,and from checks caused by drying.Knife checks can havea significant effect on rolling shear properties in plywoodpanels and may be of significance in other veneer co
15、ntaining1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.03 on Panel Products.Current edition approved Nov.1,2018.Published November 2018.Originallyapproved in 1969.Last previous edition approved in 2011 as D2718 00(2011)1.
16、DOI:10.1520/D2718-18.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the
