1、Designation: D 3500 90 (Reapproved 2003)Standard Test Methods forStructural Panels in Tension1This standard is issued under the fixed designation D 3500; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 These test methods cover the determination of thetens
3、ile properties of structural panels.1.2 Structural panels in use include plywood, waferboard,oriented strand board and composites of veneer, and otherwood-based layers1.3 Test Method A, Tensile Test for Small Specimens:1.3.1 This test method employs small specimens that shouldhave a reduced cross se
4、ction at the center of their length toavoid failure in the grip area. The transition from full width ofspecimen to reduced section at the center should be gradual tominimize stress concentration.1.3.2 When the measurements of elastic properties are to bemade, the length of the reduced cross section
5、at the centershould be of sufficient length to accommodate an extensometer.1.4 Test Method B, Tensile Test for Large Specimens:1.4.1 This test method employs large specimens and re-sponds well to manufacturing variables, plywood growthcharacteristics, and other defects influencing the tensile prop-e
6、rties of structural panels.1.4.2 The test specimens are large enough to contain themaximum sized defects found in plywood panels. The testspecimens have a constant cross section since the size andlocation of defects control the location of failures and the effectof stress concentration at the grips
7、is overshadowed.1.4.3 This test method is recommended for the following:1.4.3.1 Comparative tests of structural panels,1.4.3.2 Determining the influence of any specific strengthreducing defects on the tensile properties of structural panels,1.4.3.3 Determination of tensile properties of plywood andc
8、omposites containing veneer with growth and manufacturingcharacteristics.1.5 This standard does not purport to address all of thesafety concerns, 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
9、the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 2395 Test Methods for Specific Gravity of Wood andWood-Base Materials2D 4442 Test Method for Direct Moisture Content Measure-ment of Wood and Wood-Base Materials23. Significance and Use3.1 These tes
10、t methods determine the tensile properties ofstructural panels in response to stresses acting in the plane ofthe panel.3.2 Test Method AThis test method is suited to materialthat is uniform with respect to tensile properties. It is normallyapplied to structural panels and plywood of clear, straight-
11、grained veneers. It may also be used to evaluate the strength ofscarf and finger joints and other manufacturing process vari-ables that can be expected to influence the tensile properties ofstructural panels in a uniform manner across the width of thesheet.3.3 Test Method BThis test method employs l
12、arge testspecimens and responds well to all manufacturing variablesand growth characteristics that affect the tensile properties ofstructural panels.3.4 It is recommended that where comparisons are to bemade that the same test method and specimen size be usedthroughout. This is because the volume of
13、 material included ina test specimen can influence the tensile strength regardless ofwhether the material properties are uniform throughout thesheet or vary widely due to the presence of growth ormanufacturing features.4. Control of Moisture Content4.1 Structural panel specimens to be tested at spec
14、ificmoisture contents or after reaching equilibrium moisture con-tent at specific temperature and relative humidity conditionsshall be conditioned to approximate constant weight in con-trolled atmospheric conditions. For approximating moistureconditions of structural panels used under dry conditions
15、, arelative humidity of 65 6 2 % at a temperature of (68 6 6F)(20 6 3C) is recommended.1These 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. 26, 1990. Published December 199
16、0. Originallypublished as D 3500 76. Last previous edition D 3500 76 (1986).2Annual Book of ASTM Standards, Vol 04.10.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Variables Influencing Tensile Properties of StructuralPanels5.1
17、Moisture ContentMoisture content shall be deter-mined in accordance with Test Method D 4442.5.2 Specific GravityDetermine specific gravity in accor-dance with Test Methods D 2395. The specimen may be thesame as that for moisture content determination but must havevolume of at least 1 in.3(16 cm3) if
18、 from small specimens (TestMethod A), and at least 3 in.3(49 cm3) if from large specimens(Test Method B). Specimens containing veneer shall be free ofvisible knots or voids in any ply.TEST METHOD ATENSILE PROPERTIESOF SMALL SPECIMENS6. Test Specimens6.1 Specimens may be of Types A, B, or C in Fig. 1
19、.6.1.1 When the evaluation of elastic properties as well asultimate tensile strength is required, the size and shape of thetest specimen shall be selected on the basis of the constructionand thickness of the material. For other structural panels, andplywood or composites with the grain of the indivi
20、dual veneerplies or laminations making grain angles of individual veneerlamina of 0 or 90, Type A shall be used for material over14 in.(6 mm) in thickness and Type B for material14 in. (6 mm) orless in thickness. For plywood with an angle other than 0 or 90between the length of the specimens and the
21、 grain orientation,Type C shall be used regardless of the thickness of the material.The specimens shall have a thickness equal to that of thematerial. The thickness and the width of each specimen at thecritical section shall be measured to an accuracy of not lessthan 60.3 % or 0.001 in. (0.02 mm) wh
22、ichever is larger.6.1.2 The test specimens shall be properly shaped, using atemplate in conjunction with a vertical-spindle wood-work-ingshaper or any other method that will give equally satisfactoryresults.7. Loading Procedure7.1 Hold the specimen in wedge-type self-tightening andself-aligning grip
23、s. Rate of crosshead motion shall be constantthroughout the test such that the specimen breaks within 3 to 10min after initiation of loading. A crosshead motion rate ofU.S. CustomaryUnits, in.Metric EquivalentsmmU.S. CustomaryUnits, in.Metric Equivalentsmm14 6378 9812 13 418 10512514 108178 48 16 40
24、6212 64 20 503258 67 25 635278 73 30 762NOTE 1A generous radius of curvature at the minimum section as provided in this specimen is highly desirable.FIG. 1 Dimensions and Details of Tension Test SpecimensD 3500 90 (2003)20.035 in./min (0.9 mm/min) is usually satisfactory. If failuredoes not occur wi
25、thin the desired 3 to 10-min time span, adjustthe loading rate.7.2 Measure the elapsed time from initiation of loading tomaximum load and record to the nearest12 min.8. Load-Deformation Curves8.1 Take data for load-deformation curves to determine themodulus of elasticity and the proportional limit.
26、Chooseincrements of load so that not less than 12 and preferably 15 ormore readings of load and deformation are taken to theproportional limit. Attach the deformation apparatus at thecenter of the specimens length and width. Take deformationreadings to the nearest 0.0001 in. (0.002 mm). Fig. 2 and F
27、ig.3 show 2-in. (51-mm) gage length Tripolitis extensometers thathave been found satisfactory for this test.TEST METHOD BTENSILE STRENGTH OFLARGE SPECIMENS9. Apparatus9.1 Hold the structural panel specimen in grips that applythe required forces to the specimen without influencing load at,or location
28、 of, failure. Such devices shall not apply a bendingmoment to the test section, allow slippage under load, or inflictdamage or stress concentrations to the test section. Figs. 4 and5 illustrate the test set-up and grips.9.2 Grip AlignmentFor ideal test conditions, the gripsshould be self-aligning, t
29、hat is, they should be attached to theforce mechanism of the machine in such a manner that theywill move freely into axial alignment as soon as the load isapplied and thus apply uniformly distributed forces along andacross the test cross section. When self-aligning grips are notavailable, the specim
30、en may be clamped in the heads of auniversal-type testing machine with wedge-type jaws.9.3 Contact SurfaceThe contact surface between gripsand test specimen shall be such that slippage does not occur. Itis recommended that 11-in. (279-mm) long gripping area beused (measured parallel to direction of
31、force). Large projec-tions that damage the contact surface of the wood should beavoided. Grips that have been used successfully include:diamond floor plate, grips surfaced with coarse emery paper,and urethane friction padding.10. Test Specimens10.1 Specimens shall be precisely cut with all adjacente
32、dges at right angles. The dimension of the specimen shall beat least 6 in. (152 mm) wide by 48 in. (1219 mm) long. Thethickness and width shall be measured to an accuracy of notless than 60.3 % or 0.001 in. (0.02 mm), whichever is larger.11. Loading Procedure11.1 Apply the load continuously througho
33、ut the test at auniform rate of moveable crosshead motion that will producefailure of the specimen withina3to10-min time period afterinitiation of loading. A strain rate of 0.001 in./in.min (0.001mm/mmmin)6 25 % has been found to give satisfactoryresults. This rate corresponds to a crosshead motion
34、of approxi-mately 0.025 in./min (0.625 mm/min) for a net specimenlength of 26 in. (600 mm). Widely varying material propertiesor deformation of loading equipment may cause failure timesto fall outside this range, requiring an adjustment of loadingrate.11.2 Measure the elapsed time from initiation of
35、 loading tomaximum load and record to the nearest12 min.12. Load-Deformation Curves12.1 When deformation measurements are needed for de-termining elastic properties mount a pair of transducers on theopposite faces of the specimen to minimize the effect ofbending. Attach the transducers at the mid le
36、ngth and width ofthe specimen. It is recommended that the deflection be mea-sured over a gage length of at least 5 in. (127 mm) andFIG. 2 Tension Test of Thick Plywood Showing NonaveragingType of Extensometer (2-in. Gage Length)D 3500 90 (2003)3deformations measured to the nearest 0.0001 in. (0.002
37、mm). Itis recommended that an X-Y recorder be used to obtain acontinuous load-deformation curve. Otherwise choose theincrements of load so that not less than 12 and preferably 15 ormore readings of load and deformation are taken to theproportional limit.REPORT13. Report13.1 The structural panel spec
38、imen shall be described as tosize, species, construction, and adhesive type used in itsmanufacture, and (where applicable) direction of the face grainor orientation with respect to load direction. The test methodshall be identified.13.2 Data for individual specimens and, where applicable,specimen av
39、erages shall include:13.2.1 Thickness,13.2.2 Width,13.2.3 Specific gravity,13.2.4 Moisture content,13.2.5 Elapsed time to failure,13.2.6 Tensile stiffness (cross-sectional area 3 modulus ofelasticity),13.2.7 Maximum load,13.2.8 Maximum tensile strength,13.2.9 Load-deflection diagrams, and13.2.10 Des
40、cription of failure.13.3 It may also be desirable to include additional data thatmay influence results such as, for plywood, cross-sectional areaof parallel and perpendicular plies, thickness of individualplies, and natural and manufacturing features present relatingto panel grade or thought to infl
41、uence test results.13.4 A description of the test method shall include equip-ment used to apply loads to the specimen, deformation mea-suring equipment, and geometry of deformation measured.14. Precision14.1 The precision of these test methods has not yet beendetermined, but when data are available
42、a precision statementwill be included.15. Keywords15.1 panels; structural panels; tensile properties;wood-basedFIG. 3 Tension Test of Plywood with Extensometer AttachmentShowing Specimen Used When Load is Applied at an AngleOther than 0 or 90 Deg to the Direction of the Grain of the PliesD 3500 90 (
43、2003)4FIG. 4 Test Method B Tension Test Set-UpD 3500 90 (2003)5ASTM International takes no position respecting 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
44、 patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This 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
45、 either for revision of this standard or for additional standardsand should be addressed to ASTM International 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 f
46、air hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.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).FIG. 5 Grips Suitable for Test Method B Tension TestsD 3500 90 (2003)6
