1、Designation: D3501 05a (Reapproved 2011)Standard Test Methods forWood-Based Structural Panels in Compression1This standard is issued under the fixed designation D3501; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in 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 These test methods cover the determinati
3、on of thecompression properties of wood-based structural panels.Wood-based structural panels in use include plywood, wafer-board, oriented strand board, and composites of veneer and ofwood-based layers.1.2 Method A, Compression Test for Small SpecimensThismethod is applicable to small specimens that
4、 are uniform withrespect to elastic and strength properties. Two types of com-pression tests are employed: one to evaluate both elastic andcompressive strength properties, and the second to evaluatemaximum compressive strength only.1.3 Method B, Compression Test for Large SpecimensThis method employ
5、s large specimens and responds well tomanufacturing variables and growth characteristics that influ-ence compression properties of structural panels.1.3.1 This method is intended for the following:1.3.1.1 Comparative tests of structural panels,1.3.1.2 Evaluating the effects of moisture content onstr
6、ength properties of structural panels,1.3.1.3 Determining the strength properties of structuralpanels, and1.3.1.4 Evaluating the effects of raw material and manufac-turing variables on compression properties of structural panels.1.4 The values stated in inch-pound units are to be regardedas standard
7、. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 standa
8、rd 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:2D2395 Test Methods for Specific Gravity of Wood andWood-Based MaterialsD4442 Test Methods for Direct Moisture Content Measure-me
9、nt of Wood and Wood-Base Materials3. Significance and Use3.1 These methods determine the compressive strength ofstructural panels in response to stresses acting in the plane ofthe panel.3.2 Method AThis method is applicable to structuralpanels of uniform properties within a panel. It is useful forev
10、aluating plywood of clear, straight-grained veneers, anddetermining the effect of chemical or preservative treatments,construction, principal direction with respect to direction ofstress, and other variables that are expected to uniformlyinfluence the panel.3.3 Method B:3.3.1 The compressive propert
11、ies obtained by this methodare a reliable approximation of the strength of a full-size panel,and are intended for use in design.3.3.2 The compressive properties are influenced by buck-ling; however, this effect can be eliminated in this test byrestraining the edges of the specimens.3.4 It is recomme
12、nded that where comparisons are to bemade, that the same method and specimen size be usedthroughout. This is because the volume of material included ina test specimen can influence the compressive strength regard-less of whether the material properties are uniform throughout1These test methods are u
13、nder the jurisdiction of ASTM Committee D07 onWood and are the direct responsibility of Subcommittee D07.03 on Panel Products.Current edition approved Nov. 1, 2011. Published November 2011. Originallyapproved in 1976. Last previous edition approved in 2000 as D3501 05a. DOI:10.1520/D3501-05aR11.2For
14、 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
15、, West Conshohocken, PA 19428-2959, United States.the sheet or vary widely due to the presence of growth ormanufacturing features.4. Control of Moisture Content4.1 Condition structural panel samples to be tested at aspecific moisture content or relative humidity to approximateconstant weight in cont
16、rolled atmospheric conditions beforetesting. For panels used under dry conditions, a relativehumidity of 65 6 2 % at a temperature of 68 6 6F (20 6 3C)is preferred.5. Variables Influencing the Compressive Properties ofStructural Panels5.1 Moisture ContentCut a moisture content sample hav-ing minimum
17、 area of 2 in.2(13 cm2) from the clear areas of thespecimen and weigh immediately after each test. Moisturecontent samples from large specimens of Method B shall haveminimum area of 8 in.2(52 cm2). If inspection of the edges ofa plywood panel reveals the presence of a knot in any ply,select a second
18、 sample. Moisture content samples also servingas specific gravity samples shall be free of voids. Moisturecontent determinations shall be made in accordance with TestMethods D4442.5.2 Specific GravityDetermine specific gravity in accor-dance with Test Methods D2395. The specimen may be thesame as th
19、at for moisture content determination but must havevolume of at least 1 in.3(16 cm3) if from small specimens, andat least 3 in.3(49 cm3) if from large specimens, and be free ofvisible knots or voids.METHOD ACOMPRESSION TESTFOR SMALL SPECIMENS6. Direction of Grain, Fibers, or Layers6.1 The direction
20、of the individual plies, laminations, orlayers shall be parallel, perpendicular, or inclined at any otherrequired angle to the length of the test specimen.7. Test Specimen7.1 The test specimen shall be rectangular in cross section.The thickness, width, and length of each specimen shall bemeasured to
21、 an accuracy of not less than 60.3 % or 0.001 in.(0.02 mm), whichever is larger.7.2 When tests to evaluate both elastic and compressivestrength properties are required, the size of the specimens shallbe as follows:7.2.1 For Material Over14 in. (6 mm) in Thickness, thespecimens shall have a thickness
22、 equal to that of the materialand the width shall be a minimum of 1 in. (25 mm), but not lessthan the thickness. The length shall be not greater than seventimes the least cross-sectional dimension.7.2.2 For Material14 in. (6 mm) or Less in Thickness, thespecimen shall have the following dimensions:
23、thickness equalto that of the material; the width nominally 1 in. (25 mm), anda length of 4 in. (100 mm). Such specimens shall be supportedlaterally throughout the test.7.2.3 When tests to evaluate maximum compressivestrength only are required, an alternative type of specimen 4 in.(100 mm) in width
24、and a length equal to six times the thicknessmay be used.7.2.4 The end surfaces of the specimen shall be smooth andparallel to each other and at right angles to the length.8. Evaluation of Both Compressive Strength and ElasticProperties8.1 Support laterally test specimens14 in. (6 mm) or less inthic
25、kness intended for use in obtaining load deformation datato prevent buckling during the test, but do not exert unduepressure against the sides of the specimen. This support shallnot measurably restrain the normal compressive deformationunder load. A satisfactory method of providing lateral supportis
26、 illustrated in Fig. 1, and a detailed design of this apparatusis shown in Fig. 2.9. Loading Procedure9.1 Apply the load through a spherical bearing block pref-erably of the suspended, self-aligning type.Apply the load witha continuous motion of the movable head so as to cause failurewithin 3 to 10
27、min after initiation of loading. A rate of 0.003in./in. (mm/mm) of length of the specimen per minute within apermissible variation of 625 % has usually proved satisfac-tory.9.2 Measure the elapsed time from initiation of loading tomaximum load and record to the nearest12 min.10. Load-Deformation Cur
28、ves10.1 Take data for load-deformation curves to determine themodulus of elasticity and the proportional limit. Chooseincrements of load so that not less than 12 readings of load anddeformation are taken to the proportional limit. Read thedeformation to the nearest 0.0001 in. (0.002 mm). Attachcompr
29、essometers over the central portion of the length of thespecimen with the points of attachment not less than34 in. (18mm) from the specimen ends. Fig. 3 shows a type of Lambsroller compressometer, with a 2-in. (50-mm) gage length issuitable for specimens 312 to 6 in. (90 to 150 mm) in length. Asuita
30、ble arrangement of a Martins mirror having a 2-in.(50-mm) gage length for measuring deformations of laterallysupported specimens is illustrated in Fig. 1.11. Alternative Test for Evaluation of MaximumCompressive Strength Only11.1 In the alternative test for the evaluation of maximumcompressive stren
31、gth only, apply the load through a sphericalloading block with a continuous rate of cross-head movementso as to produce failure within 3 to 10 min after initiation ofloading. A loading rate of 0.003 in./in. (mm/mm) of length perminute is suggested. The loading rate shall be modified if timesfall out
32、side the 3 to 10-min range. Record the maximumcrushing force and calculate the maximum crushing stress.METHOD BCOMPRESSION TESTFOR LARGE SPECIMENS12. Test Specimens12.1 Specimens shall be precisely cut with all adjacentedges at right angles. The dimension of the specimen shall be712 in. (190 mm) wid
33、e by 15 in. (381 mm) long measured to anaccuracy of not less than 60.3 %.D3501 05a (2011)212.2 To eliminate buckling, the following length-to-thickness ratios shall be used:12.2.1 A ratio of 20 or less, if data are to be recorded up tothe proportional limit only, and12.2.2 A ratio of 10 or less, if
34、strength data only arerequired.12.3 In order to obtain the specified length-to-thicknessratios, it is necessary, in some cases, to glue two or morespecimens face to back.13. Loading Procedure13.1 Apply the load through a hinged connection on theupper head of the testing machine to allow for any devi
35、ationsfrom parallel of the ends of the specimens, and permitadjustment to the end of the specimen in one direction.Specimen buckling can be restrained by use of optionalhardware shown in Fig. 4. If restraint is used, hold thespecimen loosely by the side restraining rail. Apply the loadcontinuously t
36、hroughout the test at a rate of movable headmotion that will produce failure within 3 to 10 min afterinitiation of loading. A head speed rate of 0.035 in./min (0.9mm/min) 625 % is suggested. This gives a strain rate ofapproximately 0.002 in./in.min (0.002 mm/mmmin). Typicalloading hardware is shown
37、in Fig. 5 and Fig. 4.14. Load-Deformation Curves14.1 Take data for load-deformation curves to determinemodulus of elasticity and the proportional limit. Chooseincrements of load so that not less than 12 readings of load anddeformation are taken to the proportional limit. Take deforma-tion readings t
38、o the nearest 0.0001 in. (0.002 mm). Takedeformation over the central portion of both sides of thespecimen with a gage length of 5 in. (127 mm). Use theaverage of the two readings in calculation of the modulus ofelasticity. A suitable arrangement is shown in Fig. 4 withdeformation measured by transd
39、ucers mounted on oppositesides of the specimen. Record the load and deflection electri-cally and display continuous data on a suitable device.15. Calculation of Results15.1 Calculate Results:15.1.1 Compressive modulus of elasticity shall be calcu-lated as follows:Ec5 P/d!L!/A see Note1! (1)where:Ec=
40、 Compressive modulus of elasticity (psi)P/d = slope of the linear portion of load-deformation curve(lb/in.) (see Note 2)L = deformation gage length (in.)A = cross-sectional area (in.2)NOTE 1Reporting compressive stiffness on a capacity basis (such asEAc(lb) or EAc/width (lb/ft) is an acceptable alte
41、rnative.NOTE 2Normal techniques to determine the slope of the load-deformation curve, such as measuring the maximum slope below theproportional limit, are often difficut to apply to compressive stiffness testsdue to absence of a readily identifiable linear portion or proportional limit,or both. One
42、suitable technique to determine the slope is to determine thebest linear fit in the range of 5 to 35 % of the ultimate load. In any case,data covering a range of at least 20 % of the ultimate load and includingFIG. 1 Compression Test of Thin Structural Panel Supported Laterally Showing Martens Mirro
43、r Compressometer for MeasuringDeformations on Two Opposite FacesD3501 05a (2011)3loads up to and including applicable design stress should be used.15.1.2 Compressive strength shall be calculated as follows:Fc5 Pmax/A see Note3! (2)where:Fc= Compressive strength (psi)Pmax= maximum load (lb)A = cross-
44、sectional area (in.2)NOTE 3Reporting compressive stress on a capactiy basis (such as FcAor FcA/width) are acceptable.REPORT16. Report16.1 The structural panel specimen, shall be described as tospecies, construction, and adhesive type used in its manufac-ture, and the principal direction with respect
45、 to load direction,andTABLE 2U.S. CustomaryUnits, in.Metric Equivalents,mmU.S. CustomaryUnits, in.Metric Equivalents,mm0.024 0.61 1316 3018 3112 3838 10 21932 6612 13 22532 7158 16 3916 901116 17 378 981332 18 41516 125FIG. 2 Apparatus for Lateral Support for Compression TestD3501 05a (2011)416.2 De
46、scription of compressive test method used, includ-ing whther optional restraining device is used (for Method B),and deformation gauge.16.3 Data for individual specimens and specimen averageswhere applicable shall include the following:16.3.1 Thickness of panel,16.3.2 Construction and veneer thicknes
47、ses (plywood pan-els),16.3.3 Veneer or furnish species,16.3.4 Moisture content,16.3.5 Specific gravity,16.3.6 Elapsed time to failure,16.3.7 Load-deflection curve or ultimate load,16.3.8 Description of failure,16.3.9 Compressive stiffness and compressive strength, and16.3.10 Elastic modulus and ulti
48、mate compressive strength.17. Precision and Bias17.1 The bias of these test methods have not yet beendetermined due to lack of an applicable standard referencematerial.17.2 The precision of these test methods has not yet beendetermined.17.3 Based on an interlaboratory study of compressivestiffness o
49、f plywood and OSB using Method B, the reproduc-ibility standard deviation was found to vary between 173 000lb/ft and 1 870 000 lb/ft for panels with compressive stiffnessranging between 3 940 000 lb/ft and 7 950 000 lb/ft.18. Keywords18.1 compression; structural panels; woodFIG. 3 Compression Test of Plywood Prism Showing RollerCompressometer Attachment (2-in. Gage Length) AffordingAverage Deformation for Two Opposite FacesD3501 05a (2011)5FIG. 4 Method B, Loading Hardware Showing a Specimen Mounted with Transducers for Deformation Me
