1、Designation: B769 11Standard Test Method forShear Testing of Aluminum Alloys1This standard is issued under the fixed designation B769; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers double-shear testing of wroughtand cast aluminum products to determine shear ultimatestrengths.NOTE 1The values stated in inch-po
3、und units are to be regarded as thestandard. The values given in parentheses are provided for informationonly.1.2 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 safet
4、y and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 The following documents of the issue in effect on thedate of material purchase, unless otherwise noted form a part ofthis specification to the extent referenced herein:2.2 ASTM S
5、tandards:2B565 Test Method for Shear Testing of Aluminum andAluminum-Alloy Rivets and Cold-Heading Wire and RodsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691
6、 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 The definitions of terms relating to shear testing inTerminology E6 are applicable to the terms used in this testmethod.4. Summary of Test Method4.1 This test method consists of subjecting a
7、 machinedcylindrical test specimen to double-shear loading in a testfixture using a tension (or compression) testing machine todetermine the shear stress required to fracture the specimen,that is, the shear strength.5. Significance and Use5.1 The intent of this method is to provide a means ofmeasuri
8、ng the ultimate shear strength of aluminum-alloywrought and cast products. Data obtained by this method areused to calculate minimum properties that can be utilized in thedesign of structural members such as found in aircraft. It isrecognized that loading conditions developed by this method,and by m
9、ost others, are not ideal in that they do not strictlysatisfy the definition of pure shear. However, rarely do pureshear conditions exist in structures.NOTE 2This method is not interchangeable with that described in TestMethod B565. Shear strengths obtained by Test Method B565 are about10 % lower th
10、an those developed by this test method.5.2 The presence of a lubricant on the surface of thespecimen and fixture may result in shear strengths up to 3 %lower than those determined in the absence of lubrication (see8.1 and Test Method B565).6. Apparatus6.1 Testing MachinesThe testing machines shall c
11、onformto the requirements of Practices E4. The loads used todetermine the shear strength shall be within the loading rangeof the testing machine as defined in Practices E4.6.2 Loading Device:6.2.1 The loading device shall be a double-shear test fixtureof the type shown in Fig. 1. The fixture shall b
12、e made of toolsteel having a Rockwell hardness from 60 to 62 HRC. Asuitable alternative is to use a lower-strength steel for the mainframe of the fixture and have only the steel inserts hardenedfrom 60 to 62 HRC.6.2.2 The shearing edges of the holes shall have a radius ofno more than 0.0005 in. (0.0
13、13 mm). The mating surfaces ofthe center and outside dies shall have a finish of 16 in. (0.4m) Raor less. There shall be sufficient clearances between thedie interfaces to ensure that no binding occurs; clearanceshould not exceed 0.002 in. (0.051 mm). Consequently, therigidity of the test fixture mu
14、st be such that this clearance ismaintained throughout the test; in instances where the device is1This test method is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.05 onTesting.Current edition approved Nov. 1, 2011. Publis
15、hed December 2011. Originallyapproved in 1987. Last previous edition approved in 2007 as B76907. DOI:10.1520/B0769-11.2For 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 t
16、o the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.loaded in compression as in Fig. 1, care must be taken to ensu
17、rethere is no binding between the dies at the interfaces during thetest.6.2.3 The nominal length of the center and outside dies ofthe tool shown in Fig. 1 is 1 in. (25.4 mm). It has beendemonstrated that die lengths of 0.5 in. (12.7 mm) for38-in.(9.52 mm) diameter specimens give test results compara
18、ble todies 1 in. in length.3The initial minimum length of any one dieshall be 0.5 in. (12.7 mm) for specimens up through 0.375 in.(9.52 mm) in diameter. The minimum die lengths for speci-mens greater than 0.375 in. in diameter should be kept in aboutthe same proportion as that of the 0.375-in. diame
19、ter specimen;that is, die length/specimen diameter equal to43 .As a result ofsharpening, dies shall be replaced when lengths are less than95 % of the original lengths.NOTE 3The specimen should not be restrained by clamping circum-ferentially or end loading during the test.7. Test Specimens7.1 The mi
20、nimum length of the cylindrical specimens shallbe equal to the combined lengths of the three dies in accor-dance with 6.2.3.7.2 The minimum specimen size shall be316 in. (4.76 mm)in diameter. The 0.375-in. (9.52-mm) diameter specimen is acommonly used size, but up to 0.500-in. (12.7-mm) diameterspec
21、imens have been used.7.3 Measurements of the specimen diameter shall be madeto the nearest 0.0005 in. (0.013 mm). Measurements are to bemade at the two shear planes; the average of the two diameterswill be used to calculate the specimen cross-sectional area.7.4 The maximum clearance between the spec
22、imen diam-eter and the test-hole diameter shall not exceed 0.0015 in.(0.038 mm).7.5 The finish shall be 32 in. (0.8 m) Raor less.8. Specimen Orientation and Direction8.1 The shear strength of an aluminum material usuallydepends on the specimen orientation and the direction in whichthe load is applie
23、d relative to the grain flow in the specimen.3The specimen orientation and the loading direction should beidentified by the following systems:8.1.1 The reference directions for rectangular shapes areindicated in Fig. 2; these are suitable for plate, extrusions,forgings and other shapes of nonsymmetr
24、ical grain flow.8.1.2 The reference directions for certain cylindrical shapeswhere the longitudinal axis is the predominate grain flow areindicated in Fig. 3. The terminology in Fig. 3 is applicable torolled, drawn, extruded or forged round rod.8.2 The two-letter code is used in Fig. 2 and Fig. 3 to
25、describe the specimen orientations and loading directions. Thefirst letter designates the grain orientation normal to the shearplane. The second letter designates the direction of loading.The most commonly used specimen orientations and loadingdirections are L-S, T-S and S-L for shapes in 8.1.1 and
26、L-R, C-Rand R-L for cylindrical shapes in 8.1.2.3Davies, R. E., and Kaufman, J. G., “Effects of Test Method and SpecimenOrientation on Shear Strengths of Aluminum Alloys,” Proceedings, ASTM, Vol 64,1964.FIG. 1 Three Views of an Amsler Shear ToolB769 1128.3 Some type of mark, such as a scribed line s
27、hown in Fig.2 and Fig. 3, is necessary to indicate the orientation of thespecimen relative to a reference surface of the material.9. Procedure9.1 Clean the specimen and dies with a suitable solvent suchas acetone for removal of lubrication.9.2 Place the specimen in a test fixture of the type shown i
28、nFig. 1.9.3 The cross-head speed of the testing machine shall notexceed 0.75 in./min (19.1 mm/min) and the loading rate shallnot exceed 100 ksi/min (689 MPa/min) on the double-shearcross section. Loading rate to failure should be uniform.9.4 Determine the maximum load to fracture the specimen.9.5 Th
29、e mating surfaces of the shear dies should be visuallyinspected before use for aluminum buildup around the testholes. Removal of the aluminum can be accomplished withcrocus cloth or soaking the dies in a caustic soda solutionfollowed by a water rinse and drying.10. Calculation10.1 Calculate the shea
30、r strength from the maximum load asfollows:S 5 Pmax/A 5 Pmax/pD2/4! 5 2Pmax/pD2where:S = shear strength, psi (MPa),Pmax= maximum load, lbf (N), andD = measured diameter of the specimen, in. (mm).11. Report11.1 The report shall include the following:11.1.1 ASTM method of shear test,NOTE 4Since the te
31、st method significantly influences the test results,it is essential that the ASTM method be referenced.11.1.2 Material and sample identification,11.1.3 Specimen diameter, in in. (mm),11.1.4 Specimen orientation and loading direction,FIG. 2 Grain Orientations and Loading Directions for Shear Specimen
32、s from Rectangular ShapesFIG. 3 Grain Orientations and Loading Directions for Shear Specimens from Cylindrical ShapesB769 11311.1.5 Maximum load, in lbf (N),11.1.6 Shear strength, ksi (MPa), and11.1.7 Test temperature, F (C).12. Precision and Bias12.1 The precision of this test method is based on an
33、interlaboratory study conducted in 2009. Each of six laborato-ries tested five different materials. Every test result representsan individual determination. Laboratories reported three repli-cate test results (from a single operator). Practice E691 wasfollowed for the design and analysis of the data
34、; the details aregiven in RR:B07-10034.12.1.1 Repeatability Limit, rTwo test results obtainedwithin one laboratory shall be judged not equivalent if theydiffer by more than the r value for that material; r is the intervalrepresenting the critical difference between two test results forthe same mater
35、ial, obtained by the same operator using thesame equipment on the same day in the same laboratory.12.1.1.1 Repeatability limits are listed in Table 1.12.1.2 Reproducibility Limit, RTwo test results shall bejudged not equivalent if they differ by more than the R valuefor that material; R is the inter
36、val representing the criticaldifference between two test results for the same material,obtained by different operators using different equipment indifferent laboratories.12.1.2.1 Reproducibility limits are listed in Table 1.12.1.3 The above terms (repeatability limit and reproduc-ibility limit) are
37、used as specified in Practice E177.12.1.4 Any judgment in accordance with statements 12.1.1and 12.1.2 would have an approximate 95% probability ofbeing correct.12.2 BiasAt the time of the study, there was no acceptedreference material suitable for determining the bias for this testmethod, therefore
38、no statement on bias is being made.12.3 The precision statement was determined through sta-tistical examination of 90 results, from six laboratories, on fivematerials. These five materials were identified as the following:Material A AA2024-T351, 0.750 in. thickMaterial B AA5383-H111, 1.128 in.Materi
39、al C AA6061-T651, 0.625 in.Material D AA7050-T7451, 3.500 in.Material E AA7475-T7351, 4.000 in.12.4 To judge the equivalency of two test results, it isrecommended to choose the material closest in characteristicsto the test material.13. Keywords13.1 aluminum alloys; cast aluminum products; double-sh
40、ear testing; shear strength; wrought aluminum productsSUMMARY OF CHANGESCommittee B07 has identified the location of selected changes to this standard since the last issue (B769 07)that may impact the use of this standard. (Approved November 1, 2011)(1) Added Section 12 and Table 1.4Supporting data
41、have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:B07-1003.TABLE 1 Shear Strength, ksiMaterial AverageARepeatabilityStandardDeviationReproducibilityStandardDeviationRepeatabilityLimitReproducibilityLimitxSxSrSRrRA 42.587 1.673 0.724 1.774 2.026 4.
42、968B 28.008 0.989 0.516 1.075 1.445 3.009C 32.078 1.201 0.659 1.316 1.844 3.684D 48.292 1.723 0.576 1.786 1.613 5.002E 43.474 2.097 0.583 2.150 1.633 6.020AThe average of the laboratories calculated averages.B769 114ASTM International takes no position respecting the validity of any patent rights as
43、serted 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 time
44、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 will rec
45、eive 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 Int
46、ernational, 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/).B769 115
