1、Designation: D5764 97a (Reapproved 2018)Standard Test Method forEvaluating Dowel-Bearing Strength of Wood and Wood-Based Products1This standard is issued under the fixed designation D5764; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides the basic procedure forevaluating dowel-bearing strength of wood and wood-
3、basedproducts. The bearing test results are used to determine thestatic load resistance and deformation characteristics of con-nections in wood and wood-base products resulting from theapplication of a load transmitted by a fastener inserted into apredrilled hole, or driven without drilling. Methods
4、 are givenfor preparing specimens with predrilled holes larger than thefastener diameter and specimens with holes produced byinserting fasteners in holes smaller than the fastener diameter.The methods apply to fasteners such as dowels, bolts, nails,spikes, drift pins, screws, lag screws, and staples
5、.1.2 This test method also provides the basis for determiningthe compression behavior of wood products beneath a laterallyloaded fastener where the thickness of the product and thediameter of the fastener are such that minimal bending of thefastener occurs during testing.1.3 This standard does not p
6、urport 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international stan
7、dard was developed in accor-dance with internationally 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. R
8、eferenced Documents2.1 ASTM Standards:2D143 Test Methods for Small Clear Specimens of TimberD2395 Test Methods for Density and Specific Gravity (Rela-tive Density) of Wood and Wood-Based MaterialsD2915 Practice for Sampling and Data-Analysis for Struc-tural Wood and Wood-Based ProductsD4442 Test Met
9、hods for Direct Moisture Content Measure-ment of Wood and Wood-Based MaterialsE4 Practices for Force Verification of Testing Machines3. Terminology3.1 Definitions:3.1.1 dowel-bearing behaviorthe load-deformation be-havior of wood or wood-base products laterally loaded by afastener where the fastener
10、 does not bend during loading.3.1.2 dowel-bearing strengthyield load obtained from theload-deformation curve of a dowel-bearing test divided by thedowel diameter and specimen thickness.4. Summary of Test Method4.1 Specimens consisting of a single rectangular parallele-piped member with a fastener ho
11、le perpendicular to the faces ofthe member are evaluated for the resistance to embedding thefastener into the fastener hole, so as not to bend the fastener.Tests are conducted on a testing machine at a uniformdeformation rate, while loads and deformation are measured atvarious intervals. Supplementa
12、ry physical properties of thewood or wood-base member are also determined.5. Significance and Use5.1 The localized crushing behavior of wood or wood-baseproducts beneath a fastener where the fastener does not bendprovides a material property that is used in theoretical modelsfor connections where cr
13、ushing or fastener bending, or both,occur. These theoretical models are used to establish designvalues for wood and wood-base connections. The tests areappropriate when studying the effects of such variables asfastener diameter, fastener hole size, moisture content, specificgravity, and grain direct
14、ion on the dowel-bearing strength.6. Apparatus6.1 Testing MachineAny suitable testing machine capableof operation at a constant rate of motion of its movable headand having an accuracy of 61 % when calibrated in accor-dance with Practices E4.1This test method is under the jurisdiction of ASTM Commit
15、tee D07 on Woodand is the direct responsibility of Subcommittee D07.05 on Wood Assemblies.Current edition approved March 1, 2018. Published April 2018. Originallyapproved in 1995. Last previous edition approved in 2013 as D5764 97a (2013).DOI: 10.1520/D5764-97AR18.2For referenced ASTM standards, vis
16、it 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 19428-29
17、59. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical
18、Barriers to Trade (TBT) Committee.16.2 Deformation GageA deformation-measuring device,with a least reading of 0.001 in. (0.025 mm) for measuring themovement of the fastener into the wood or wood-base speci-men.7. Sampling7.1 Sampling shall provide for selection of representativetest specimens which
19、are appropriate to the objectives of thetesting program.7.2 Sample size shall be estimated using procedures inPractice D2915.NOTE 1The precision required, the manner of sampling, and thenumber of tests will depend upon the specific test objectives. Generalexperience indicates that the coefficient of
20、 variation from embedment testsranges from 15 to 30 %.8. Specimens8.1 Wood members shall be selected, and the dowel posi-tioned in such a way that the results are not affected by knots,cross grain, or other natural or manufacturing characteristics,unless the objective of the study is to determine th
21、e effect ofsuch variables. Frequently, this will necessitate selecting mem-bers which are essentially clear and straight grained. Forwood-based products, specimens shall be selected with regardto manufactured characteristics.8.2 Specimen Dimensions:8.2.1 Specimens shall consist of a rectangular para
22、llele-piped member with half a dowel hole across one face (see Fig.1).8.2.2 For solid wood and wood composites, minimumdimensions shall be made large enough so splitting does notoccur during fabrication and not less than as follows (see Fig.1):Thickness $ the smaller of 112 in. (38 mm), or 2 dowel d
23、iametersWidth $ the larger of 2 in. (50 mm) or 4 dowel diametersLength $ the larger of 2 in. (50 mm) or 4 dowel diametersNOTE 2For driven dowels in species that tend to split, larger thanminimum dimensions are recommended to prevent splitting duringspecimen preparation and testing.8.2.2.1 For specim
24、ens that tend to split before the comple-tion of the test, a full hole test configuration is allowed in Fig.2. Minimum dimensions shall be made large enough sosplitting does not occur during fabrication and not less than asfollows (see Fig. 3):Thickness $the smaller of 112 in. (38 mm) or 2 dowel dia
25、metersWidth $the larger of 2 in. (50 mm) or 4 dowel diametersLength:Loaded End $the larger of 2 in. (50 mm) or 4 dowel diametersUnloaded End $the larger of 1 in. (50 mm) or 2 dowel diameters8.2.3 For wood-base panel products, the minimum thicknessshall be the thickness of the panel. Minimum width an
26、d lengthshall be the same as for solid wood.NOTE 1Half of the fastener hole is produced by drilling oversizedhole or by the method shown in Fig. 4.FIG. 1 Specimen Configuration FIG. 2 Schematic of Testing SetupFull HoleD5764 97a (2018)28.2.4 Fastener holes for fasteners that are installed in drilled
27、holes that are equal to or greater than the fastener diametershall be typical of those used in service. Drill the holeperpendicular and through the specimen and into an adjacentwood block to minimize splitting of the face where the drill bitexits. Then saw the specimen through the hole to produce as
28、pecimen with a half hole. For bolts, the hole shall be116 in.(1.6 mm) larger than the bolt diameter. If other hole sizes arespecified for the fastener, specimens shall have the specifiedhole size.8.2.5 Fastener holes for fasteners that are driven or insertedby other means in holes that are smaller t
29、han the fastenerdiameter shall be typical of those in service. Use a pilot hole ofthe size specified for service conditions for the fastener. Whenpilot holes are used with nails, they shall be less than 75 % ofthe nail diameter (except wood members with specific gravitygreater than 0.60 shall have l
30、ead holes less than 90 % of thenail diameter). The fastener shall be driven perpendicular toand through the test specimen and into an adjacent wood blockto minimize spalling of the face where the fastener exits. Ifwhen removed, the fastener does not affect the hole surface, ahalf hole shall be produ
31、ced by removing the fastener andsawing through the hole. When removed, if the fastener affectsthe hole surface, a half hole shall be produced by the procedureoutlined in Fig. 4.9. Conditioning9.1 The tests shall be made with material conditioned to theappropriate conditions for the objectives of the
32、 testing pro-gram. Care shall be taken to maintain the desired condition ofthe material prior to and during testing, unless specifiedotherwise.10. Procedure10.1 Half-Hole Testing SetupPlace the dowel in the dowelhole. Place the specimen in the testing machine (see Fig. 5), sothat a compressive load
33、can be uniformly applied to the dowelalong its length. A steel loading block of sufficient size toprevent bending of the dowel during loading shall be usedbetween the dowel and movable crosshead.NOTE 3It may be necessary to provide lateral support to thinspecimens loaded in compressions.10.2 Full-Ho
34、le Testing SetupPlace the dowel in the dowelhole. Place the specimen in the testing machine so that acompressive load can be applied to the ends of the dowel usingan assembly as shown in Fig. 2.NOTE 4It may be necessary to provide lateral support to thinspecimens loaded in compression.NOTE 5If bendi
35、ng of the dowel is observed during loading, consid-eration of a half-hole test setup is recommended.NOTE 6For full-hole bolt embedment specimens, experience hasshown that a thickness of 2 to 3 bolt diameters (2 diameters thickness 3 diameters) and an end distance equal to or greater than seven boltF
36、IG. 3 Specimen ConfigurationFull HoleNOTE 1The procedure is as follows:(1) Cut specimen at point where fastener is to be driven.(2) Clamp the two pieces together with sufficient pressure to maintaincontact between adjoining faces during nailing.(3) Drill lead hole in seam of abutting pieces.(4) Driv
37、e fastener in lead hole.(5) Remove clamps and smaller piece.(6) The remaining piece is the test specimen with the fastener insertedin the hole.FIG. 4 Means of Producing a Half-Hole Specimen When the Fas-tener Cannot Be Removed Without Affecting the Hole SurfaceFIG. 5 Schematic of Testing SetupD5764
38、97a (2018)3diameters will provide embedment displacements at failure greater thanthe 5 % offset limit.10.3 Deformation MeasurementThe deformation of thefastener shall be taken as the movement of the moveablecrosshead of the testing machine. Measure the movement witha linear variable differential tra
39、nsducer (LVDT), (see Fig. 5), orother suitable device.NOTE 7Equipment setup should be checked for tightness to ensurethat there is no significant relaxation under load that would be erroneouslyrecorded as dowel deformation.10.4 Rate of TestingConduct the test to reach maximumload in 1 to 10 min. Rec
40、ord the rate of testing used.NOTE 8Aconstant rate of movement of the moveable crosshead of thetesting machine of 0.04 in./min (1.0 mm/min) 650 % usually permitsreaching maximum load in the prescribed time.10.5 TestingMeasure the deformation from the beginningof load application, and take readings at
41、 sufficiently frequentload intervals to permit establishment of a satisfactory load-deformation curve. Observe the general behavior of thespecimen, and record the observations. Record the first relax-ation of load indicated on the testing machine load scale, themode of failure, maximum load, and oth
42、er significant details.The test shall be terminated at an embedment of one half thefastener diameter or after maximum load has been reached.10.6 Minor Tests:10.6.1 Determine the oven-dry specific gravity and moisturecontent of each specimen tested. Procedures for determiningthese properties are give
43、n in Test Methods D2395 and D4442.11. Interpretation of Results11.1 Yield LoadThe bearing yield load (see Fig. 6)isdetermined by the following procedure:11.1.1 Fit a straight line to the initial linear portion of theload-deformation curve.11.1.2 Offset this line by a deformation equal to 5 % of thef
44、astener diameter.11.1.3 Select the load at which the offset line intersects theload-deformation curve. In those cases where the offset linedoes not intersect the load-deformation curve, the maximumload shall be used as the yield load.NOTE 9Compute the dowel-bearing strength by dividing the yieldload
45、 by the fastener diameter and the specimen thickness.11.2 Proportional Limit LoadThe proportional limit load(see Fig. 5) is the load at which the load-deformation curvedeviates from a straight line fitted to the initial portion of theload-deformation curve.12. Report12.1 Report the following informa
46、tion:12.1.1 Data on load deformation relationships, maximumload, and yield load,12.1.2 Mode of failure,12.1.3 Description of the wood species or wood-base prod-uct being tested,12.1.4 Member dimensions, including length, width,thickness, and fastener hole diameter or lead hole diameter,12.1.5 Detail
47、s of loading procedure and deformation mea-surement system,12.1.6 Number of replicate tests,12.1.7 Oven-dry specific gravity,12.1.8 Moisture content at time of test of each specimen,12.1.9 Moisture content at time of fabrication of eachspecimen if different than moisture content at time of test,12.1
48、.10 Orientation of the wood grain with respect to thedirection of the applied load,12.1.11 Dimensions and other descriptive information aboutthe fastener, and12.1.12 Details of any deviation from the prescribed orrecommended methods as outlined in this test method.13. Precision and Bias13.1 The prec
49、ision and bias of this test method has not yetbeen determined.14. Keywords14.1 dowel-bearing strength; wood-baseFIG. 6 Definition of Loads Obtained from the Load-DeformationCurveD5764 97a (2018)4ASTM 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 patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject
