Compresion norma

rDesignation: E 9 – 89a (Reapproved 2000)

Standard Test Methods of

Compression Testing of Metallic Materials at Room Temperature1
This standard is issued under the fixed designation E 9; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) 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. Scope 1.1 These test methods cover the apparatus, specimens, and procedure for axial-load compression testing of metallic materials at room temperature (Note 1). For additional requirements pertaining to cementedcarbides, see Annex A1.
NOTE 1—For compression tests at elevated temperatures, see Practice E 209.

E 209 Practice for Compression Tests of Metallic Materials at Elevated Temperatures with Conventional or Rapid Heating Rates and Strain Rates3 E 251 Test Methods for Performance Characteristics of Metallic Bonded Resistance Strain Gages3 3. Terminology 3.1 Definitions: The definitions of termsrelating to compression testing and room temperature in Terminology E 6 and Specification E 171, respectively, shall apply to these test methods. 3.2 Definitions of Terms Specific to This Standard: 3.2.1 buckling—In addition to compressive failure by crushing of the material, compressive failure may occur by ( 1) elastic instability over the length of a column specimen due to nonaxiality of loading, (2)inelastic instability over the length of a column specimen, (3) a local instability, either elastic or inelastic, over a small portion of the gage length, or (4) a twisting or torsional failure in which cross sections rotate over each other about the longitudinal specimen axis. These types of failures are all termed buckling. 3.2.2 column—a compression member that is axially loaded and that may failby buckling. 3.2.3 radius of gyration—the square root of the ratio of the moment of inertia of the cross section about the centroidal axis to the cross-sectional area:
r 5 ~I/A! 1/2 (1)

1.2 The values stated in inch-pound units are to be regarded as the standard. The metric equivalent values cited in the standard may be approximate. 1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: B 557 Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products2 E 4 Practices for ForceVerification of Testing Machines3 E 6 Terminology Relating to Methods of Mechanical Testing3 E 83 Practice for Verification and Classification of Extensometer3 E 111 Test Method for Young’s Modulus, Tangent Modulus, and Chord Modulus3 E 171 Specification for Standard Atmospheres for Conditioning and Testing Flexible Barrier Materials4 E 177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods5
1These test methods are under the jurisdiction of ASTM Committee E28 on Mechanical Testing and are the direct responsibility of Subcommittee E28.04 on Uniaxial Testing. Current edition approved March 31, 1989. Published May 1989. Originally published as E 9 – 24 T. Last previous edition E 9 – 89. 2 Annual Book of ASTM Standards, Vol 02.02. 3 Annual Book of ASTM Standards, Vol 03.01. 4 Annual Bookof ASTM Standards, Vol 15.09. 5 Annual Book of ASTM Standards, Vol 14.02.

where: r = radius of gyration, I = moment of inertia of the cross section about centroidal axis (for specimens without lateral support, the smaller value of I is the critical value), and A = cross-sectional area. 3.2.4 critical stress—the axial uniform stress that causes a column to be on the verge of buckling. The...