1、Designation: D3499 11Standard Test Method forToughness of Wood-Based 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 i
2、n parentheses 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 Department of Defense.1. Scope1.1 This test method for toughness of wood-based structuralpanels
3、covers the determination of energy necessary to causefailure by impact loading of a beam specimen which is simplysupported and loaded at midspan. Wood-based structural pan-els in use include plywood, waferboard, oriented strand board,and composites of veneer and of wood-based layers.1.2 The values s
4、tated in inch-pound units are to be regardedas 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
5、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:2D143 Test Methods for Small Clear Specimens of TimberD2395 Test Methods f
6、or Specific Gravity of Wood andWood-Based MaterialsD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Base Materials3. Significance and Use3.1 The failure of wood-based materials with impact loadsis sometimes an important criteria in design considerations. Inaddition, some
7、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 The toughness t
8、esting 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 and shall car
9、ry 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 angles thr
10、ough 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 as to pr
11、oduce complete failure by the timethe downward swing is completed.NOTE 1The set-up shown in Fig. 1 has been found to give satisfactoryresults.5. Test Specimen5.1 The toughness test specimen to be used in conjunctionwith the Forest Products Laboratory toughness testing machineshall be58 in. (16 mm) i
12、n width for material less than58 in. (16mm) in thickness, and the thickness of the specimen shall beequal to that of the material. For material more than58 in. (16mm) in thickness, the width shall be equal to the thickness ofthe material, thus making the specimen square in cross section.The length s
13、hall be determined from the thickness of thematerial in accordance with Table 1. The actual cross-sectionaldimensions, and the specimen and span length shall be mea-sured to an accuracy of not less than 60.3 % or 0.001 in. (0.02mm) whichever is larger.6. Control of Moisture6.1 Panel specimens to be
14、tested at specific moisture con-tents or after reaching equilibrium moisture content at specifictemperature and relative humidity conditions shall be condi-tioned to approximate constant weight in controlled atmo-spheric conditions. For approximating moisture conditions of1This test method is under
15、the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.03 on Panel Products.Current edition approved May 1, 2011. Published June 2011. Originallyapproved in 1976. Last previous edition approved in 2000 as D3499 94 (2005).DOI: 10.1520/D3499-11.2For referenc
16、ed 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
17、nshohocken, PA 19428-2959, United States.panels used under dry conditions, a relative humidity of 65 62 % at a temperature of 68 6 6F (20 6 3C) is recommended.7. Span and Supports7.1 The test specimen shall be supported as a beam on twovertical pins, which exert reactions that are perpendicular to t
18、heplane of the panels or laminations. These pins shall be adjustedto the span length taken from Table 1 which provides for aspecimen overhang of 1 in. (25 mm) at each end.8. Loading Procedure8.1 Apply the load at the center of the span perpendicular tothe plane of the plies. Apply the load through a
19、 tup, attached toa flexible cable, having a radius of curvature approximatelyequal to one and one-half times the depth of the test specimen.Choose the weight position and initial angle of the pendulumso that complete failure of the specimen is obtained on onedrop. Most satisfactory results are obtai
20、ned when the differencebetween the initial and final angle is at least 10.NOTE 2In order to satisfy these conditions properly, it will benecessary to use a toughness testing machine of proper capacity for thespecimens being tested. The larger size specimens can be tested in thelarge size Forest Prod
21、ucts Laboratory toughness machine which has amaximum capacity of 673 inlbf (76 J), while tests of smaller specimenscan be made in the 20 inlbf (2.3 J), capacity intermediate size machine.9. Calculation9.1 Read the initial and final angle to the nearest 0.2 bymeans of the attached vernier. Calculate
22、the toughness asfollows:T 5 wL cos A22 cos A1! (1)where:T = toughness (work per specimen), inlbf (or J),w = weight of the pendulum, lbf (or kgf),L = distance from the center of the supporting axis to thecenter of gravity of the pendulum, in. (or mm),A1= initial angle (Note 3), deg, andA2= final angl
23、e the pendulum makes with the verticalafter failure of the test specimen, deg.NOTE 3Since friction is compensated for in the machine adjustment,the initial angle may be regarded as exactly 30, 45, or 60, as the case maybe.10. Moisture Content and Specific Gravity10.1 Moisture ContentCut a moisture c
24、ontent samplewhich is full width and at least 1 in. (25 mm) in length from thespecimen and weigh immediately after each test. If inspectionof the edges of a plywood specimen reveals the presence of aknot in any of the inner plies, select a second sample. Moisturecontent samples also serving as speci
25、fic gravity samples shallbe free of voids. Moisture content determinations shall bemade in accordance with Test Method D4442.10.2 Specific GravityDetermine the specific gravity inaccordance with Test Methods D2395. The specimen may bethe same as that for moisture content determination but musthave v
26、olume of at least 0.2 in.3(3 cm3), and be free of visibleknots or voids.11. Report11.1 The specimen shall be described as to species, con-struction, and adhesive type used in its manufacture.FIG. 1 Toughness Test of Structural Panel Showing Load Applied to Specimen When Pendulum is Approximately 15
27、from the VerticalTABLE 1 Length of Toughness Test SpecimensPanel Thickness, in. (mm)Span Length Specimen Lengthin. mm in. mmup to18 (3), incl 2 50 4 100Over18 (3) to14 (6), incl 3 75 5 125Over14 (6) to38 (9), incl 5 125 7 175Over38 (9) to12 (12), incl 6 150 8 200Over12 (12) to58 (16), incl 8 200 10
28、250Over58 (16) to34 (18), incl 9 230 11 275Over34 (18) to 1 (25), incl 12 300 14 350D3499 11211.2 Data for individual specimens and specimen averagesshall include:11.2.1 Specimen thickness,11.2.2 Length,11.2.3 Span length,11.2.4 Moisture content,11.2.5 Specific gravity, and11.2.6 Toughness (work per
29、 specimen), inlbf (or J).12. Precision and Bias12.1 The precision and bias of this test method have not yetbeen determined, but when data are available, a precision andbias statement will be included.13. Keywords13.1 plywood; structural panels; toughness; woodASTM International takes no position res
30、pecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This
31、standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Intern
32、ational Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown be
33、low.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D3499 113
