1、Designation: D 3528 96 (Reapproved 2008)Standard Test Method forStrength Properties of Double Lap Shear Adhesive Joints byTension Loading1This standard is issued under the fixed designation D 3528; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe accuracy of the results of strength tests of adhesive bonds will depend on the conditi
3、ons underwhich the bonding process is carried out. Unless otherwise agreed upon between the manufacturer andthe purchaser, the bonding conditions should be prescribed by the manufacturer of the adhesive. Inorder to ensure that complete information is available to the individual conducting the tests,
4、 themanufacturer of the adhesive should furnish numerical values and other specific information for eachof the following variables:(1) Surface preparation(2) Mixing directions(3) Adhesive application(4) Assembly conditions(5) Curing conditions(6) Testing conditionsA range may be prescribed for any v
5、ariable by the manufacturer of the adhesive if it can be assumedby the test operator that any arbitrarily chosen value within 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
6、covers the determination of the tensileshear strengths of adhesives for bonding metals when tested inan essentially peel-free standard specimen that develops adhe-sive stress distribution representative of that developed in atypical low-peel production-type structural joint. The repro-ducibility of
7、the strengths achieved are directly related toconformance with specified conditions of preparation andtesting.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety co
8、ncerns, 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 the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A 167 Specification for Stainless and
9、 Heat-ResistingChromium-Nickel Steel Plate, Sheet, and StripB 36/B 36M Specification for Brass Plate, Sheet, Strip, AndRolled BarB 152/B 152M Specification for Copper Sheet, Strip, Plate,and Rolled BarB 209 Specification for Aluminum and Aluminum-AlloySheet and PlateB 265 Specification for Titanium
10、and Titanium Alloy Strip,Sheet, and PlateD 618 Practice for Conditioning Plastics for TestingD 907 Terminology of AdhesivesE4 Practices for Force Verification of Testing MachinesE 122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot
11、or Process1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.80 on MetalBonding AdhesivesCurrent edition approved April 1, 2008. Published April 2008. Originallyapproved in 1976. Last previous edition approved in 2002 as
12、 D 3528 96 (2002).2For 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 Har
13、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E 171 Specification for Atmospheres for Conditioning andTesting Flexible Barrier Materials3. Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D 907.4. Significance and Use4.1 This test method is
14、 designed to produce shear propertydata for the process control and specification of adhesives. Thistest method may also be useful for research and developmentof adhesives.4.2 Lap shear properties vary with specimen configurationpreparation, speed, and environment of testing. Consequently,where prec
15、ise comparative results are desired, these factorsmust be carefully controlled and reported.5. Apparatus5.1 Testing Machine, conforming to the requirements ofPractices E4. The testing machine should be so selected thatthe breaking load of the specimens falls between 15 and 85 %of the full-scale capa
16、city. The machine should be capable ofmaintaining a rate of loading of 8.27 to 9.65 MPa (1200 to1400 psi)/min, or if the rate is dependent on crosshead motion,the machine should be set to approach the rate of loading. Itshould be provided with a suitable pair of self-aligning grips tohold the specim
17、en. The grips and attachments should be soconstructed that they will move into alignment with the testspecimen as soon as the load is applied, so that the long axis ofthe test specimen will coincide with the direction of the appliedpull through the center line of the grip assembly.6. Test Specimen6.
18、1 The test specimens should conform to one of thealternative types as dimensioned and shown in Fig. 1 or Fig. 2.Cut the specimens from the appropriate test panels that havebeen prepared as prescribed in Section 7. For aluminum-alloyspecimens the recommended thickness of the sheet is 3.24 60.125 mm (
19、0.125 6 0.005 in.). The recommended test overlaplength (L) for most metals, with adherends of the prescribedmetal thickness and arranged as shown in Figs. 1 and 2, is 12.76 0.25 mm (0.5 6 0.01 in.).NOTE 1Since it is undesirable to exceed the yield point of the metalin tension during test, the permis
20、sible length of overlap in the specimenwill vary with the thickness and type of metal and on the general level ofstrength of the adhesive being investigated. The maximum permissiblelength may be computed from the following relationship:L 5Fty t1tand L 5Fty t22where:L = length of overlap, in., (Figs.
21、 1 and 2),t1= thickness of doubler, in., (Figs. 1 and 2),t2= thickness of adherend in., (Figs. 1 and 2),Fty = yield point of adherend (or stress at proportional limit), psi, andt = 150 % of the estimated average shear strength of the adhesivebond, psi.NOTE 2Variations in adherend thickness, and of t
22、he length of theoverlap, normally influence the test values and make direct comparison oftest data questionable. Therefore, it is preferable for the comparative orspecification tests, to standardize on the typical specimen configurationshown with appropriate adherend gages as computed in accordance
23、withNote 1. When specimens incorporating special lap lengths are developedfor specific studies, the adherend gage and geometry, once established,should not be altered.6.2 The following grades of metals are recommended forthe test specimens:T1=1.6mmT2=3.2mmA = Test GluelinesB = Spacer = T2C = Area in
24、 Test GripsD Shear AreaFIG. 1 Form and Dimensions of Type A SpecimensT1=1.6mmT2=3.2mmA = Test GluelinesB = Area in Test GripsC = Shear areasFIG. 2 Form and Dimensions of Type B SpecimenD 3528 96 (2008)2Brass Specification B 36/B 36M, CDA 268Copper Specification B 152/b 152M, CDA 110Aluminum Specific
25、ation B 209, Alloy 2024, T3 TemperCorrosion-resisting steel Specification A 167, Type 302, 2B FinishTitanium Specification B 265, Grade 36.3 The minimum sample size necessary to develop typicalor design values for a given joint geometry should be specifiedon the test request in accordance with the p
26、rinciples presentedin Practice E 122. Because of inherent variations in adhesiveproperties, due to process variables, specimens should beselected from a minimum of four different test panels.7. Test Specimens7.1 It is recommended that the test panels be of a widthsufficient to be cut into at least f
27、ive test specimens unaffectedby panel joint edge variables. Do the cutting operation in amanner that will not overheat, damage by exposure to unsat-isfactory coolants, or mechanically damage the bonded joints.Panels of two alternative configurations are shown in Figs. 3and 4 from which the test spec
28、imens (Fig. 1 or Fig. 2) may becut. Vary the adherend sheet length to accommodate changes inbond lap length. Cut sheets of the prescribed adherend metalsto suitable size. The edges of the metal panels which will bewithin (or bound) the lap joints should be free of burrs,deformation, and bevels. The
29、bond faying surfaces should besmooth (rms 160 max) before the panels are surface treated andbonded. Prepare the bond faying surfaces carefully in accor-dance with the procedure prescribed by the adhesive manufac-turer or the governing approved process specification andassemble with adequate spacer s
30、heets to prevent bondlinedeformation in the lap area. Prepare and apply the adhesive inaccordance with the prescribed process specification. Theprime coat, if used, apply to a bond area faying surface insufficient width to extend beyond the lap bond area byapproximately 6 mm (0.125 in.). The adhesiv
31、e, liquid or film,apply or position in the bond area limiting its extension beyondthe adherends to 1.62 6 0.25 mm (0.064 6 0.001 in.) toprevent excessive filleting. Cure the adhesive in conformancewith the prescribed process specification.NOTE 3Bonding specimens in multiple-width panels is believed
32、toproduce the most representative individual test specimens. Die-punchedpanels or individual specimens may be used for special studies; however,fabrication problems will be increased due to inadvertent slippage of theindividual adherends.8. Procedure8.1 Precondition the finished specimens as specifi
33、ed in thetest request. Conduct room temperature tests under controlledtemperature and relative humidity conditions in accordancewith Specification E 171 (23 6 2C (73.4 6 3.6F) and 50 65 % relative humidity.8.2 Conduct depressed or elevated temperature tests in acontrolled chamber. The chamber should
34、 be of sufficient size toaccommodate the test grips for preconditioning and thermalstability during the test. After the test chamber and grips havebeen brought to equilibrium, place an instrumented dummyspecimen in the grips and calibrate the bondline temperaturefor each desired test condition.NOTE
35、4It is recommended that the dummy specimen be calibrated bythe following procedure. Instrument the specimen with two thermo-couples. Position one in the geometric center of the bondline and securethe second to the external surface, in the geometric center of the metal laparea. Position and secure th
36、e dummy specimen in the test grips within thethermally stabilized test chamber. Record the time required for thebondline to reach the test temperature. Monitor and simultaneously recordA=Predrilled Pinholes(4 required; 2.4-mm diameter)FIG. 3 Form and Dimensions of Standard Test Panel for Type ASpeci
37、mensA =Predrilled Pinholes(4 required; 2.4-mm diameter)B =Suggest TFE-fluorocarbon Filler for Adhesive Flash ControlFIG. 4 Form and Dimensions of Standard Test Panel for Type BSpecimensD 3528 96 (2008)3the temperature of the surface thermocouple.8.3 Measure the width of the specimen and the overlapl
38、engths of the nearest 0.25 mm (0.01 in.) to determine the shearareas.8.4 Place the specimens in the grips of the test machine sothat the terminal 31.8-mm (1.25-in.) ends are engaged firmlyand so that the long axis of the test specimen coincides with thedirection of the pull.8.4.1 There should be no
39、slack in the test linkage just priorto applying a load; a preload, if used, shall not exceed 350 kPa(50 psi) during final stabilization and soak.8.4.2 Control the temperature exposure, where applicable,by the cycle determined with the calibration. A periodic checkof the cycle may be made by attachin
40、g a thermocouple to theexternal surface of a test specimen in a manner similar to thecalibration test.8.5 The test temperature tolerance shall be in accordancewith Practice D 618.8.6 Unless otherwise specified, load the test specimen tofailure at a rate of 8.27 to 9.65 MPa (1200 to 1400 psi)/min.Thi
41、s rate of loading will be approximated by a free crossheadspeed of 1.27 mm (0.05 in.)/min.8.7 Record the load at failure, the test temperature and soaktime, the nature and amount of failure (cohesion in theadhesive, adhesion between adhesive and metal or metal).Failing stresses shall be expressed in
42、 kilograms per squarecentimetre (or pounds-force per square inch) of total shear area(both bond lines) calculated to the nearest 0.06 cm.2(0.01 in.2),and to the third significant figure.9. Report9.1 The report should include the following:9.1.1 Complete identification of the adhesive tested, includ-
43、ing type, form, source, manufacturers code numbers, procure-ment specification number (where applicable), weight persquare foot (square metre) at application and cured gluelinethickness,9.1.2 Complete identification of the adherend material, theindividual adherend thicknesses and the heat treat cond
44、ition(where applicable),9.1.3 Adherend preparation for bonding,9.1.4 Adhesive application and bonding conditions used inpreparation of the specimens (specification number, whereapplicable),9.1.5 Final width of specimen and length of bond overlapmeasured to the nearest 0.25 mm (0.01 in.),9.1.6 Condit
45、ioning procedures for specimens prior to test-ing,9.1.7 Test temperature and soak time,9.1.8 Number of specimens tested, coded for positions intest panels,9.1.9 Type of specimen and number of test panels repre-sented,9.1.10 Maximum, minimum, average, and coefficient ofvariation for the stress at fai
46、lure, and9.1.11 Nature of failure, including the estimated percentageof failure in cohesion and adhesion or metal failure.10. Precision and Bias10.1 A precision and bias statement does not exist for thistest method because resources necessary for round-robin test-ing have not been forthcoming.11. Ke
47、ywords11.1 metals; shear; tension; testingASTM 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 t
48、he 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 either for revision
49、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 fair 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 s
