ASTM E9-2009 6875 Standard Test Methods of Compression Testing of Metallic Materials at Room Temperature《室温下金属材料压缩试验的标准试验方法》.pdf

1、Designation: E9 09Standard 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 year of last revisio

2、n. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the apparatus, specimens

3、, 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-pound units are to be r

4、egardedas 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 theresponsibility of the u

5、ser 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:2B557 Test Methods for Tension Testing Wrought and CastAluminum- and Magnesium-Alloy ProductsE4 Practices for F

6、orce 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 ModulusE171 Specification for Atmospheres for Conditioning andTesting F

7、lexible Barrier MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE209 Practice for Compression Tests of Metallic Materialsat Elevated Temperatures with Conventional or RapidHeating Rates and Strain RatesE251 Test Methods for Performance Characteristics of Me-tallic B

8、onded Resistance Strain GaugesE691 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 andSpecification E171, respectively, shall app

9、ly to these testmethods.3.2 Definitions of Terms Specific to This Standard:3.2.1 bucklingIn addition to compressive failure bycrushing of the material, compressive failure may occur by ( 1)elastic instability over the length of a column specimen due tononaxiality of loading, (2) inelastic instabilit

10、y 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 axis. These types offailures are all termed buckling

11、.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:r5I/A!1/2(1)1These test methods are under the jurisdiction of A

12、STM Committee E28 onMechanical Testing and are the direct responsibility of Subcommittee E28.04 onUniaxial Testing.Current edition approved Nov. 1, 2009. Published December 2009. Originallypublished in 1924. Last previous edition approved in 2000 as E9 -89a(2000) whichwas withdrawn March 2009 and re

13、instated in November 2009. DOI: 10.1520/E0009-09.2For 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 (

14、C) ASTM International. 100 Barr Harbour Drive PO Box C-700 West Conshohocken, Pennsylvania 19428-2959, United StatesCopyright by ASTM Intl (all rights reserved); Tue Jul 20 03:47:12 EDT 2010Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.where

15、:r = radius of gyration,I = 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 area.3.2.4 critical stressthe axial uniform stress that causes acolumn to be on the verge of buckling.

16、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 material its value maybe calculated using the Euler equation:Scr5 Cp2E/L/r!2(2)If the buckling stress is gre

17、ater than the proportional limit ofthe material its value may be calculated from the modifiedEuler equation:Scr5 Cp2Et/L/r!2(3)where:Scr= critical buckling stress,E = Youngs modulus,Et= tangent modulus at the buckling stress,L = column length, andC = end-fixity coefficient.Methods of calculating the

18、 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. 1). These values are:Freely rotating ends (pinned or hinged) C =1(a)One end fixed, the other free to r

19、otate 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 deformation of the end regionsof a test specimen under compressive load due to friction at thespecimen end secti

20、ons 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 is given in Ref (2).4. Summary of Test Methods4.1 The specimen is subjected to an increasing axial co

21、m-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 data obtained from a compressiontest may include the yield strength, the yield point, Youngsmodulus, th

22、e 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 dependent on total strain andspecimen geometry.5.2 UseCompressive properties are of interest in theanal

23、yses 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. For brittle or nonductile metals thatfracture in tension at stresses below the yield strength, com-pr

24、ession 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 materials, buckling and barreling (see Section 3) cancomplicate results and should be minimized.6. Apparatus6.

25、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 compression.6.1.1 The bearing surfaces of the heads of the testingmachine shall be parallel at all times with 0

26、.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 within 0.0002 in./in.(m/m). Lack of initial parallelism can be overcome by the useof adjustable bearin

27、g 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 greater) and when testingnonferrous materials such as aluminum, copper, etc. Thespecimen must be careful

28、ly 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 distribution of initial load as possible. An adjustablebearing block cannot be relied on to compensate fo

29、r 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 is3The boldface numbers in parentheses refer to the list of references at the end ofthis standard.FIG. 1 Diagrams Showing Fixi

30、ty Conditions and ResultingBuckling of DeformationE9092Copyright by ASTM Intl (all rights reserved); Tue Jul 20 03:47:12 EDT 2010Downloaded/printed byGuo Dehua (CNIS) pursuant to License Agreement. No further reproductions authorized.applied to the specimen. One type of adjustable bearing blockthat

31、has proven satisfactory is illustrated in Fig. 3. Anotherarrangement 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 th

32、e testspecimen (for specimens tested with the load axis vertical). Thespherical surface of the block shall be defined by a radiushaving its point of origin in the flat surface that bears on thespecimen.6.3 Alignment Device/Subpress:6.3.1 It is usually necessary to use an alignment device,unless the

33、testing machine has been designed specifically foraxial alignment. The design of the device or subpress dependson the size 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. TheNO

34、TE 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 of the tested specimen. The highly distorted flow lines are the result of friction between the specimen ends and theloading fixture. N

35、ote 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 Block for Compression TestingE9093Copyright by ASTM Intl (all rights reserved); Tue Jul 20 03:47:12 EDT 2010Downloaded/printed byGuo De

36、hua (CNIS) pursuant to License Agreement. No further reproductions authorized.bearing blocks of the device shall have the same requirementsfor parallelism and flatness as given in 6.2.1.6.3.2 The primary requirements of all alignment devices arethat the load is applied axially, uniformly, and with n

37、egligible“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 Compression Testing JigsIn testing thin specimens,such as sheet material, some means should be adopted

38、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 combination of lateral-support pressure andspring constant to prevent buckling, but without interf

39、eringwith axial deformation of the specimen. Although suitablecombinations vary somewhat with variations in specimenmaterial and thickness, testing temperatures, and accuracy ofalignment, acceptable results can be obtained with rather wideranges of lateral-support pressure and spring constant. Gener

40、-ally, the higher the spring constant of the jig, the lower thelateral-support pressure that is required. Proper adjustments ofthese variables should be established during the qualification ofthe equipment (see 6.6).6.4.1 It is not the intent of these methods to designatespecific jigs for testing sh

41、eet 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 and pass the quali-fication test set forth in 6.6. Compression jigs generally requirethat the sp

42、ecimen 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 strain shall comply with the requirements for theapplicable class described in Practice E83. Th

43、e 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 degree specified inPractice E83. The characteristics of electrical resistance straingages have bee

44、n determined from Test Methods E251.6.6 Qualification of Test Apparatus The completecompression-test apparatus, which consists of the testing ma-chine and when applicable, one or more of the following; thealignment device, the jig and the strain-measurement system,shall be qualified as follows:6.6.1

45、 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 shall be machined fromsheet or bar in the location specified in Test Methods B557.The thickness of

46、 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 qualification specimenseach provide a modulus value of 10.7 3 106psi (73.8 GPa)65 %, the apparatus qual

47、ifies.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 Cylindrical FormIt is recom-mended that, where feasible, compression test specimens be inthe form

48、 of solid circular cylinders. Three forms of solidcylindrical test specimens for metallic materials are recog-nized, and designated as short, medium-length, and long (Note4). Suggested dimensions for solid compression test specimensfor general use are given in Table 2.NOTE 4Short specimens typically

49、 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 metallicFIG. 4 Spherical-Seated Bearing BlockFIG. 5 Example of Compression Testing ApparatusE9094Copyright by ASTM Intl (all rights reserved); Tue Jul 20 03:47:12 EDT 2010Downloaded/pr