1、Designation: D1184 98 (Reapproved 2012)Standard Test Method forFlexural Strength of Adhesive Bonded LaminatedAssemblies1This standard is issued under the fixed designation D1184; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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.This standard has been approved for use by agencies of the Department of Defense.INTRODUCTIONThe accuracy of the results o
3、f strength tests of adhesive bonds will depend on the conditions underwhich the bonding process is carried out. Unless otherwise agreed upon by the manufacturer and thepurchaser, the bonding conditions shall be prescribed by the manufacturer of the adhesive. In order toensure that complete informati
4、on is available to the individual conducting the tests, the manufacturerof the adhesive shall furnish numerical values and other specific information for each of the followingvariables:(1) Procedure for preparation of surfaces prior to application of the adhesive, including the moisturecontent of wo
5、od, the cleaning and drying of metal surfaces, and special surface treatments such assanding that are not specifically limited by the pertinent test method.(2) Complete mixing directions for the adhesive.(3) Conditions for application of the adhesive including the rate of spread of thickness of film
6、,number of coats to be applied, whether to be applied to one or both surfaces, and the conditions ofdrying where more than one coat is required.(4) Assembly conditions before application of pressure, including the room temperature, length oftime, and whether open or closed assembly is to be used.(5)
7、 Curing conditions, including the amount of pressure to be applied, the length of time underpressure, and the temperature of the assembly when under pressure. It should be stated whether thistemperature is that of the glue line or of the atmosphere at which the assembly is to be maintained.(6) Condi
8、tioning procedure before testing, unless a standard procedure is specified, including thelength of time, temperature, and relative humidity.Arange may be prescribed for any variable by the manufacturer of the adhesive if it can be assumedby the test operator that any arbitrarily chosen value within
9、such a range or any combination of suchvalues for several variables will be acceptable to both the manufacturer and the purchaser of theadhesive.1. Scope1.1 This test method covers the determination of the com-parative properties of either metal or wood adhesive bondedassemblies when subjected to fl
10、exural stresses with standardshape specimens and under defined conditions of pretreatment,temperature, relative humidity, and testing technique. The testspecimen and testing technique were designed to develop alarge portion of shear forces between the laminae of the testpiece when the load is applie
11、d, rather than to reduce shearstress to a minimum as is done in other ASTM test methods forflexural properties. This method is not applicable to assembliesmade with nonrigid adherends. The data obtained are notsuitable for design work.1.2 The values stated in SI units are to be regarded as thestanda
12、rd. The values given in parentheses are for informationpurposes.1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.80 on MetalBonding Adhesives.Current edition approved May 1, 2012. Published May 12. Originally approvedi
13、n 1951. Last previous edition approved in 2004 as D1184 98 (2004). DOI:10.1520/D1184-98R12.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.1.3 This standard does not purport to address all of thesafety concerns, if any, associated wi
14、th its 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:2D907 Terminology of AdhesivesE4 Practices for Force Verification o
15、f Testing Machines3. Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D907.4. Summary of Test Method4.1 Test a specimen composed of eight bonded plies as asimple beam loaded at the mid-span. Test at conditions ofstandard temperature and humidity. Specimen flexural p
16、roper-ties are compared by generating maximum shear stress in metalspecimens and flexural strength of wood specimens usingstandard formulas.5. Significance and Use5.1 This test method is designed for both wood and metalbonded specimens.5.2 The test method provides a means to compare flexuralproperti
17、es between assemblies.5.3 The data are reduced to a comparable basis by means ofthe formulas given in 11.1 and 11.2. It is recognized that theseformulas do not apply rigidly to tests made in the mannerdescribed in this method, but serve only to reduce the data toa comparable basis.6. Apparatus6.1 Te
18、sting MachineUse a properly calibrated testingmachine, capable of maintaining a specified rate of approach ofthe two loading parts. The error for indicated load to not exceed61 %. The stiffness of the testing machine is such that the totalelastic deformation of the system does not exceed 1 % of thet
19、otal deflection of the test specimen. The load-indicatingmechanism is essentially free from inertia lag at the specifiedrate of testing. The accuracy of the testing machine is verifiedin accordance with Practices E4.6.2 Loading PieceThe center loading piece, which isattached to one loading part of t
20、he testing machine, has a radiusof at least 0.075 mm (132 in.). The rounded nose is at least 25mm (1 in.) long. If significant indentation occurs, a radius ofone and one-half times the specimen depth for a chord lengthof not less than twice the specimen depth is used.6.3 SupportsA pair of round-nose
21、d supports of the sameradius as that on the loading piece is used. The span isadjustable to 60.13 mm (0.005 in.) within the range of eighttimes the thickness of the test specimens (usually a span of 13to 38 mm (0.5 to 1.5 in.). The support device is mounted onthe one loading part of the testing mach
22、ine so that the roundednose of the loading piece on the other loading part is centeredbetween the supports.6.4 MicrometersSuitable calibrated micrometers, readingto at least 0.025 6 0.001 mm (0.001 6 0.0005 in.) is used formeasuring the width and thickness of the test specimen.6.5 Conditioning Room
23、or DesiccatorsA conditioningroom capable of maintaining a relative humidity of 50 6 2%at 23 6 1.1C (73.4 6 2F), or desiccators filled with asaturated salt solution (Note 1) to give a relative humidity of 506 2 % at 23 6 1.1C (73.4 6 2F).NOTE 1A saturated solution of calcium nitrate will give approxi
24、-mately 51 % relative humidity at 23C in a closed container.7. Test Specimens7.1 The specimen is a rectangular piece 38 mm (1.5 in.)long and 19.1 mm (0.75 in.) wide. The length of the specimenis sufficient to allow an overhang of between 2.5 and 3.8 mm(0.1 and 0.15 in.) on each end. The specimens ar
25、e machinedfrom laminated panels consisting of eight plies of 0.3-mm(0.01-in.) thick adherend material. Each ply is coated withadhesive on both sides with an even spread, and bonded. Themixing procedure, weight of spread, drying conditions, andassembly time conforms to the manufacturers directions. T
26、hemaximum shear stress is developed at the neutral surfaceapproximately midway between the top and bottom of thebeam. Thus it is important to have an even number of plies ofadherend material, so that the adhesive is in the center. Sincefailure by delamination probably begins in the center layer ofad
27、hesive, special care should be exercised in the preparation ofthis part of the specimen.7.2 Wood SpecimensThe wood panel specimens are pre-pared from 0.2 mm (0.01-in.)-thick quarter-cut veneers. Onlystraight-grain veneers shall be selected. Veneers are condi-tioned at 50 6 2 % relative humidity and
28、23 6 1.1C (73.4 62F) for at least one week before bonding. Panels are con-structed by arranging the grains of the veneers symmetricallyabout the center so that the two core veneers are parallel. Allthe other veneers are arranged so that the grain directions ofadjacent veneers are perpendicular to on
29、e another. This willresult in the grains of the face veneers being parallel to eachother. The grain on the face plies is parallel to the length of thespecimen.7.3 Metal SpecimensThe metal panel specimens are pre-pared from 0.2 mm (0.01-in.)-thick sheets.7.4 PanelsFour panels are prepared with each a
30、dhesive-adherend combination, and at least five specimens shall be cutfrom each panel for this test. The cutting of metal specimens isdone so as to avoid overheating or mechanical damage to thejoints.NOTE 2A fine-toothed typesetters circular saw has been foundsuitable for such purposes.8. Conditioni
31、ng8.1 Condition all specimens prior to test at 23 6 1.1C (73.46 2F) and 50 6 2 % relative humidity for 48 h for metal andplastics, and 7 days for wood.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStan
32、dards volume information, refer to the standards Document Summary page onthe ASTM website.D1184 98 (2012)29. Procedure9.1 Test in an atmosphere maintained at 23 6 1.1C (73.4 62F) and 50 6 2 % relative humidity. Test the specimen as asimple beam loaded at mid-span. The span-depth ratio shall be8 to 1
33、. Measure the span length to the nearest 0.13 mm (0.005in.) and the width and thickness of the specimen to the nearest0.03 mm (0.001 in.) at the center of the span.9.2 Speed of TestingCalculate the rate of approach of theloading parts for testing the specimens as follows:N 5 ZL2/6d (1)where:N = rate
34、 of approach of the loading, mm/min (or in./min),L = span, mm (or in.),d = depth of beam, mm (or in.),Z = unit rate of fiber strain, mm/mm (or in./in.) of outerfiber length per minute, the constant is 0.01. Thisconstant is the approximate calculated rate of fiberstrain for a rate of cross-head motio
35、n of 1.3 mm (0.05in.)/min, a span length of 100 mm (4 in.) and a spanlength of 100 mm (4 in.), and a depth of 13 mm (0.5in.) such as have been used with the 130 by 13 by13-mm (5 by 0.5 by 0.5-in.) test specimen.For the conditions of test described in this method, thisformula reduces to N = 0.107 d.
36、The rate of approach of theloading parts is as near as possible, but to not exceed, the valuecalculated from this formula. This permits the use of a constantrate of straining, provided the resultant rate of approach doesnot exceed the value calculated from the above formula.10. Retests10.1 Unless ot
37、herwise specified, results that deviate fromthe mean value of all tests should be rejected if the deviation ofthe doubtful value is more than five times the average deviationfrom the mean obtained by excluding the doubtful value.Discard such doubtful values and retest, unless the degree ofvariabilit
38、y is a factor that is being studied.11. Calculations11.1 For metal specimens reduce the data to a comparablebasis by means of the maximum shear stress formula, asfollows:Ss5 3P/4bd (2)where:Ss= maximum shear stress, MPa (or psi),P = breaking load, N (or lbf),b = width of beam, mm (or in.), andd = de
39、pth of beam, mm (or in.).11.2 For wood specimens, reduce the data to a comparablebasis by means of the flexural strength formula, as follows:S 5 3PL/2bd2(3)where:S = flexural strength, MPa (or psi),P = breaking load, N (or lbf),L = distance between supports, mm (or in.),b = width of beam, mm (or in.
40、), andd = depth of beam, mm (or in.).11.3 For each series of tests, calculate the arithmetic meanof all values obtained to three significant figures and report asthe“ average value” for the particular property in question.11.4 Calculate the standard deviation of each “averagevalue.”12. Report12.1 Th
41、e report includes the following:12.1.1 Complete identification of the material tested, includ-ing type, source, manufacturers code number, form, principaldimensions, and previous history,12.1.2 Method of preparing test specimens,12.1.3 Direction of cutting and loading specimens,12.1.4 Conditioning p
42、rocedure,12.1.5 Average depth and width of specimen,12.1.6 Radius of supports and nose,12.1.7 Rate of approach of loading parts in inches perminute,12.1.8 Average value of stress calculated in accordance with11.1 and 11.2, and the standard deviation, and12.1.9 Type of failure, that is, delamination,
43、 breaking orbuckling.13. Precision and Bias13.1 No precision or bias exists for this test method, as thenecessary resources have not been forthcoming.14. Keywords14.1 adhesive bonded assemblies; flexural strength;laminatesASTM International takes no position respecting the validity of any patent rig
44、hts 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 to revision at any
45、 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 International Headquarters. Your comments wi
46、ll 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 below.This standard is copyrighted by AS
47、TM 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/).D1184 98 (2012)3
