ASTM B769-2007 Standard Test Method for Shear Testing of Aluminum Alloys《铝合金的剪切测试用标准试验方法》.pdf

1、Designation: B 769 07Standard Test Method forShear Testing of Aluminum Alloys1This standard is issued under the fixed designation B 769; 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 parenth

2、eses indicates the year of last reapproval. Asuperscript epsilon (e) 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

3、-pound 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 sa

4、fety 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 AST

5、M Standards:2B 565 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 Test-ing3. Terminology3.1 The definitions of terms relating to shear testing inT

6、erminology E6are applicable to the terms used in this testmethod.4. Summary of Test Method4.1 This test method consists of subjecting a machinedcylindrical test specimen to double-shear loading in a testfixture using a tension (or compression) testing machine todetermine the shear stress required to

7、 fracture the specimen,that is, the shear strength.5. Significance and Use5.1 The intent of this method is to provide a means ofmeasuring the ultimate shear strength of aluminum-alloywrought and cast products. Data obtained by this method areused to calculate minimum properties that can be utilized

8、in thedesign of structural members such as found in aircraft. It isrecognized that loading conditions developed by this method,and by most 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 me

9、thod is not interchangeable with that described in TestMethod B 565. Shear strengths obtained by Test Method B 565 are about10 % lower than 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

10、those determined in the absence of lubrication (see8.1 and Test Method B 565).6. Apparatus6.1 Testing MachinesThe testing machines shall conformto the requirements of Practices E4. The loads used todetermine the shear strength shall be within the loading rangeof the testing machine as defined in Pra

11、ctices 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 be 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

12、 only the steel inserts hardenedfrom 60 to 62 HRC.1This 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 June 1, 2007. Published July 2007. Originally approvedin 1987. Last

13、 previous edition approved in 2006 as B 76906.2For 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.1*A Summary of

14、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.6.2.2 The shearing edges of the holes shall have a radius ofno more than 0.0005 in. (0.013 mm). The mating surfaces ofthe center and o

15、utside 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 must be such that this clearance ismaintained th

16、roughout the test; in instances where the device isloaded in compression as in Fig. 1, care must be taken to ensurethere 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 beend

17、emonstrated that die lengths of 0.5 in. (12.7 mm) for38-in.(9.52 mm) diameter specimens give test results comparable 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-

18、mens greater than 0.375 in. in diameter should be kept in aboutthe same proportion as that of the 0.375-in. diameter 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 s

19、hould not be restrained by clamping circum-ferentially or end loading during the test.7. Test Specimens7.1 The minimum 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 diame

20、ter. The 0.375-in. (9.52-mm) diameter specimen is acommonly used size, but up to 0.500-in. (12.7-mm) diameterspecimens 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 tw

21、o diameterswill be used to calculate the specimen cross-sectional area.7.4 The maximum clearance between the specimen 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 strengt

22、h of an aluminum material usuallydepends on the specimen orientation and the direction in whichthe load is applied 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 rectangula

23、r shapes areindicated in Fig. 2; these are suitable for plate, extrusions,forgings and other shapes of nonsymmetrical 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

24、 applicable torolled, drawn, extruded or forged round rod.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 ToolB7690728.2 The two-letter code is used in Fig

25、. 2 and Fig. 3 todescribe 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 sha

26、pes in 8.1.1 and L-R, C-Rand R-L for cylindrical shapes in 8.1.2.8.3 Some type of mark, such as a scribed line shown 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 suitabl

27、e solvent suchas acetone for removal of lubrication.9.2 Place the specimen in a test fixture of the type shown inFig. 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 s

28、ection. Loading rate to failure should be uniform.9.4 Determine the maximum load to fracture the specimen.9.5 The 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 soakin

29、g the dies in a caustic soda solutionfollowed by a water rinse and drying.10. Calculation10.1 Calculate the shear 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

30、. (mm).11. Report11.1 The report shall include the following:11.1.1 ASTM method of shear test,FIG. 2 Grain Orientations and Loading Directions for Shear Specimens from Rectangular ShapesFIG. 3 Grain Orientations and Loading Directions for Shear Specimens from Cylindrical ShapesB769073NOTE 4Since the

31、 test 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,11.1.5 Maximum load, in lbf (N),11.1.6 Shear strength, ksi (MPa)

32、, and11.1.7 Test temperature, F (C).12. Keywords12.1 aluminum alloys; cast aluminum products; double-shear testing; shear strength; wrought aluminum productsSUMMARY OF CHANGESCommittee B07 has identified the location of selected changes to this standard since the last issue (B769 06)that may impact

33、the use of this standard. (Approved June 1, 2007)(1) In 4.1, 5.2, and 9.2, replaced the word “jig” with “fixture.”(2) Changed the surface roughness average symbol from“AA” to “Ra” in 7.5, and in both 6.2 and 7.5 changed “better”to “less.” Included SI units for surface finish.Committee B07 has identi

34、fied the location of selected changes to this standard since the last issue (2000) thatmay impact the use of this standard. (Approved Sept. 1, 2006.)(1) In 6.2.1 and 6.2.2 replace the word “jig” with “fixture.”(2) Change the surface roughness average symbol from “AA”to “Ra.”(3) Reword the second sen

35、tence to eliminate the redundant useof “hardness.”(4) In 9.3 separate the two testing speed units.ASTM 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 determ

36、ination 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 by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or w

37、ithdrawn. Your comments are invited either for revision 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

38、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 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).B769074