ASTM E9-09(2018) Standard Test Methods of Compression Testing of Metallic Materials at Room Temperature.pdf

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1、Designation: E9 09 (Reapproved 2018)Standard Test Methods ofCompression Testing of Metallic Materials at RoomTemperature1This standard is issued under the fixed designation E9; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the ye

2、ar of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods cover the a

3、pparatus, specimens, andprocedure for axial-load compression testing of metallic mate-rials at room temperature (Note 1). For additional requirementspertaining to cemented carbides, see Annex A1.NOTE 1For compression tests at elevated temperatures, see PracticeE209.1.2 The values stated in inch-poun

4、d units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresp

5、onsibility of the user of this standard to establish appro-priate safety, health, and environmental health practices anddetermine the applicability of regulatory limitations prior touse.1.4 This international standard was developed in accor-dance with internationally recognized principles on standar

6、d-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. Referenced Documents2.1 ASTM Standards:2B557 Test Methods for Tension Testing Wrought an

7、d CastAluminum- and Magnesium-Alloy ProductsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE83 Practice for Verification and Classification of Exten-someter SystemsE111 Test Method for Youngs Modulus, Tangent Modulus,and Chord ModulusE1

8、71/E171M Practice for Conditioning and Testing FlexibleBarrier PackagingE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE209 Practice for CompressionTests of Metallic Materials atElevated Temperatures with Conventional or Rapid Heat-ing Rates and Strain RatesE251 Test Method

9、s for Performance Characteristics of Me-tallic Bonded Resistance Strain GagesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions: The definitions of terms relating to com-pression testing and room temperature in Terminology E6

10、 andPractice E171/E171M, respectively, shall apply to these testmethods.3.2 Definitions of Terms Specific to This Standard:3.2.1 bucklingIn addition to compressive failure by crush-ing of the material, compressive failure may occur by (1)elastic instability over the length of a column specimen due t

11、ononaxiality of loading, (2) inelastic instability over the lengthof a column specimen, (3) a local instability, either elastic orinelastic, over a small portion of the gage length, or (4)atwisting or torsional failure in which cross sections rotate overeach other about the longitudinal specimen axi

12、s. These types offailures are all termed buckling.3.2.2 columna compression member that is axially loadedand that may fail by buckling.3.2.3 radius of gyrationthe square root of the ratio of themoment of inertia of the cross section about the centroidal axisto the cross-sectional area: 5 I/A!1/2(1)w

13、here: = radius of gyration,1These test methods are under the jurisdiction of ASTM Committee E28 onMechanical Testing and are the direct responsibility of Subcommittee E28.04 onUniaxial Testing.Current edition approved Jan. 1, 2018. Published January 2018. Originallypublished in 1924. Last previous e

14、dition approved in 2009 as E9-09. DOI:10.1520/E0009-09R18.2For 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.Cop

15、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of Internat

16、ional Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1I = moment of inertia of the cross section about centroidalaxis (for specimens without lateral support, the smallervalue of I is the critical value), andA = cross-sectional

17、 area.3.2.4 critical stressthe axial uniform stress that causes acolumn to be on the verge of buckling. The critical load iscalculated by multiplying the critical stress by the cross-sectionarea.3.2.5 buckling equationsIf the buckling stress is less thanor equal to the proportional limit of the mate

18、rial its value maybe calculated using the Euler equation:Scr5 C2E/L/!2(2)If the buckling stress is greater than the proportional limitof the material its value may be calculated from the modi-fied Euler equation:Scr5 C2Et/L/!2(3)where:Scr= critical buckling stress,E = Youngs modulus,Et= tangent modu

19、lus at the buckling stress,L = column length, andC = end-fixity coefficient.Methods of calculating the critical stress using Eq 3 aregiven in Ref (1).33.2.6 end-fixity coeffcientThere are certain ideal speci-men end-fixity conditions for which theory will define thevalue of the constant C (see Fig.

20、1). These values are:Freely rotating ends (pinned or hinged) C =1(a)One end fixed, the other free to rotate C =2(b)Both ends fixed C =4(c)NOTE 2For flat-end specimens tested between flat rigid anvils, it wasshown in Ref (1) that a value of C = 3.75 is appropriate.3.2.7 barrelingrestricted deformatio

21、n of the end regionsof a test specimen under compressive load due to friction at thespecimen end sections and the resulting nonuniform transversedeformation as shown schematically and in the photograph inFig. 2. Additional theoretical and experimental information onbarreling as illustrated in Fig. 2

22、 is given in Ref (2).4. Summary of Test Methods4.1 The specimen is subjected to an increasing axial com-pressive load; both load and strain may be monitored eithercontinuously or in finite increments, and the mechanicalproperties in compression determined.5. Significance and Use5.1 SignificanceThe d

23、ata obtained from a compressiontest may include the yield strength, the yield point, Youngsmodulus, the stress-strain curve, and the compressive strength(see Terminology E6). In the case of a material that does notfail in compression by a shattering fracture, compressivestrength is a value that is d

24、ependent on total strain andspecimen geometry.5.2 UseCompressive properties are of interest in theanalyses of structures subject to compressive or bending loadsor both and in the analyses of metal working and fabricationprocesses that involve large compressive deformation such asforging and rolling.

25、 For brittle or nonductile metals thatfracture in tension at stresses below the yield strength, com-pression tests offer the possibility of extending the strain rangeof the stress-strain data. While the compression test is notcomplicated by necking as is the tension test for certainmetallic material

26、s, buckling and barreling (see Section 3) cancomplicate results and should be minimized.6. Apparatus6.1 Testing MachinesMachines used for compression test-ing shall conform to the requirements of Practices E4. Foruniversal machines with a common test space, calibration shallbe performed in compressi

27、on.6.1.1 The bearing surfaces of the heads of the testingmachine shall be parallel at all times with 0.0002 in./in. (m/m)unless an alignment device of the type described in 6.3 is used.6.2 Bearing Blocks:6.2.1 Both ends of the compression specimen shall bear onblocks with surfaces flat and parallel

28、within 0.0002 in./in.(m/m). Lack of initial parallelism can be overcome by the useof adjustable bearing blocks (Note 3).The blocks shall be madeof, or faced with, hard material. Current laboratory practicesuggests the use of tungsten carbide when testing steel andhardened steel blocks (55 HRC or gre

29、ater) and when testingnonferrous materials such as aluminum, copper, etc. Thespecimen must be carefully centered with respect to the testingmachine heads or the subpress if used (see 6.3, AlignmentDevice/Subpress).NOTE 3The purpose of an adjustable bearing block is to give thespecimen as even a dist

30、ribution of initial load as possible. An adjustablebearing block cannot be relied on to compensate for any tilting of theheads that may occur during the test.6.2.2 The bearing faces of adjustable bearing blocks thatcontact the specimen shall be made parallel before the load isapplied to the specimen

31、. One type of adjustable bearing block3The boldface numbers in parentheses refer to the list of references at the end ofthis standard.FIG. 1 Diagrams Showing Fixity Conditions and Resulting Buck-ling of DeformationE9 09 (2018)2that has proven satisfactory is illustrated in Fig. 3. Anotherarrangement

32、 involving the use of a spherical-seated bearingblock that has been found satisfactory for testing material otherthan in sheet form is shown in Fig. 4. It is desirable that thespherical-seated bearing block be at the upper end of the testspecimen (for specimens tested with the load axis vertical).Th

33、espherical surface of the block shall be defined by a radiushaving its point of origin in the flat surface that bears on thespecimen.NOTE 1A cylindrical specimen of AISI 4340 steel (HRC = 40) was compressed 57 % (see upper diagram). The photo macrograph was made of apolished and etched cross section

34、 of the tested specimen. The highly distorted flow lines are the result of friction between the specimen ends and theloading fixture. Note the triangular regions of restricted deformation at the ends and the cross-shaped zone of severe shear.FIG. 2 Illustration of BarrelingFIG. 3 Adjustable Bearing

35、Block for Compression Testing FIG. 4 Spherical-Seated Bearing BlockE9 09 (2018)36.3 Alignment Device/Subpress:6.3.1 It is usually necessary to use an alignment device,unless the testing machine has been designed specifically foraxial alignment. The design of the device or subpress dependson the size

36、 and strength of the specimen. It must be designedso that the ram (or other moving parts) does not jam or tilt thedevice or the frame of the machine as a result of loading. Thebearing blocks of the device shall have the same requirementsfor parallelism and flatness as given in 6.2.1.6.3.2 The primar

37、y requirements of all alignment devices arethat the load is applied axially, uniformly, and with negligible“slip-stick” friction. An alignment device that has been foundsuitable is shown in Fig. 5 and described in Ref. (3). Otherdevices of the subpress type have also been used successfully.6.4 Compr

38、ession Testing JigsIn testing thin specimens,such as sheet material, some means should be adopted toprevent the specimen from buckling during loading. This maybe accomplished by using a jig containing side-support platesthat bear against the wide sides of the specimen. The jig mustafford a suitable

39、combination of lateral-support pressure andspring constant to prevent buckling, but without interferingwith axial deformation of the specimen. Although suitablecombinations vary somewhat with variations in specimenmaterial and thickness, testing temperatures, and accuracy ofalignment, acceptable res

40、ults can be obtained with rather wideranges of lateral-support pressure and spring constant.Generally, the higher the spring constant of the jig, the lowerthe lateral-support pressure that is required. Proper adjustmentsof these variables should be established during the qualificationof the equipmen

41、t (see 6.6).6.4.1 It is not the intent of these methods to designatespecific jigs for testing sheet materials, but merely to provide afew illustrations and references to jigs that have been usedsuccessfully, some of which are cited in Table 1. Other jigs areacceptable provided they prevent buckling

42、and pass the quali-fication test set forth in 6.6. Compression jigs generally requirethat the specimen be lubricated on the supported sides toprevent extraneous friction forces from occurring at the supportpoints.6.5 Strain Measurements:6.5.1 Mechanical or electromechanical devices used formeasuring

43、 strain shall comply with the requirements for theapplicable class described in Practice E83. The device shall beverified in compression.6.5.2 Electrical-resistance strain gages (or other single-usedevices) may be used provided the measuring system has beenverified and found to be accurate to the de

44、gree specified inPractice E83. The characteristics of electrical resistance straingages have been determined from Test Methods E251.6.6 Qualification of Test ApparatusThe completecompression-test apparatus, which consists of the testing ma-chine and when applicable, one or more of the following; the

45、alignment device, the jig and the strain-measurement system,shall be qualified as follows:6.6.1 Conduct tests to establish the elastic modulus of fivereplicate specimens of 2024-T3 aluminum alloy sheet or2024-T4 aluminum alloy bar in accordance with Test MethodE111. These qualification specimens sha

46、ll be machined fromsheet or bar in the location specified in Test Methods B557.The thickness of the sheet or diameter of the bar may bemachined to the desired thickness or diameter. It is essentialthat the extensometer be properly seated on the specimenswhen this test is performed. When the qualific

47、ation specimenseach provide a modulus value of 10.7 106psi (73.8 GPa)65 %, the apparatus qualifies.6.6.2 The qualification procedure shall be performed usingthe thinnest rectangular specimen or smallest diameter roundspecimen to be tested in the apparatus.7. Test Specimens7.1 Specimens in Solid Cyli

48、ndrical FormIt is recom-mended that, where feasible, compression test specimens be inthe form of solid circular cylinders. Three forms of solidcylindrical test specimens for metallic materials arerecognized, and designated as short, medium-length, and long(Note 4). Suggested dimensions for solid com

49、pression testspecimens for general use are given in Table 2.NOTE 4Short specimens typically are used for compression tests ofsuch materials as bearing metals, which in service are used in the form ofthin plates to carry load perpendicular to the surface. Medium-lengthspecimens typically are used for determining the general compressivestrength properties of metallic materials. Long specimens are best adaptedfor determining the modulus of elasticity in compression of metallicmaterials. The specimen dimensions given in Table 2 have been u