1、Designation:D349919Standard Test Method forToughness of Wood Structural Panels1This standard is issued under the fixed designation D3499;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 parenthese
2、s indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method for toughness of wood structural panelscovers the determi
3、nation of energy necessary to cause failureby impact loading of a beam specimen which is simplysupported and loaded at midspan.Wood structural panels in useinclude plywood,oriented strand board,and composites ofveneer and of wood-based layers.1.2 The values stated in inch-pound units are to be regar
4、dedas standard.The values given in parentheses 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 t
5、his 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-dance with internationally recognized principles on standard-ization established in the Deci
6、sion 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:2D143 Test Methods for Small Clear Specimens of TimberD2395 Test Methods for Density a
7、nd 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 The failure of wood-based materials with impact loadsis sometimes an important criteria in design considerations
8、.Inaddition,some effects on the mechanical properties of wood,such as decay,are best evaluated by measuring its toughness.This test method serves to evaluate the toughness of structuralpanel products while Methods D143 can be used to measurethe toughness of solid clear wood specimens.4.Apparatus4.1
9、The toughness testing machine(Note 1)shall consist ofa frame supporting a pendulum,being so arranged that ameasured amount of the energy from the fall of the pendulummay be applied to a test specimen.The pendulum shall consistof a bar to which is fastened a weight adjustable to differentpositions an
10、d shall carry at its upper end a drum or pulleywhose center provides the axis of rotation.The force shall beapplied to the specimen by means of a flexible steel cablepassing over the drum.A stationary graduated scale or dial anda vernier operated by the moving drum shall be provided forreading the a
11、ngles through which the pendulum swings.Themachine shall be adjusted before test so that the pendulumhangs truly vertical and adjusted to correct for friction.Thecable shall be adjusted so that the load is applied to thespecimen when the pendulum swings to within approximately15 of the vertical so a
12、s to produce complete failure by the timethe downward swing is completed.NOTE1The set-up shown in Fig.1 has been found to give satisfactoryresults.Several types of machines such as the Forest Products LaboratoryToughness Machine and toughness testers from Izod and Amsler havebeen used but insufficie
13、nt information is available to decide whether oneprocedure is superior to another or whether the results by different testmachines can be directly correlated.5.Test Specimen5.1 The toughness test specimen shall be58in.(16 mm)inwidth for material less than58in.(16 mm)in thickness,and thethickness of
14、the specimen shall be equal to that of the material.For material more than58in.(16 mm)in thickness,the widthshall be equal to the thickness of the material,thus making thespecimen square in cross section.The length shall be deter-mined from the thickness of the material in accordance withTable 1.The
15、 actual cross-sectional dimensions,and the speci-men and span length shall be measured to an accuracy of notless than 60.3%or 0.001 in.(0.02 mm)whichever is larger.1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.03 on Pane
16、l Products.Current edition approved March 1,2019.Published May 2019.Originallyapproved in 1976.Last previous edition approved in 2011 as D3499 11.DOI:10.1520/D3499-19.2For 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.Unit