ASTM E9 Compression Testing of Metallic Materials at Room Temperature

Scope:

ASTM E9 determines the compressive properties of structures that will be subjected to compressive or bending loads. It determines a metal’s reaction to compressive pressures at room temperature. It is used to measure the yield strength, the yield point, Young’s modulus, the stress-strain curve, and the compressive strength of the metals.

Test Procedure:

In ASTM E9 the specimen is subjected to an increasing axial compressive load to determine its mechanical properties under compression. The dimensions of the specimen are measured. The specimen and the fixture are cleaned with acetone to remove grease (fixtures hold specimens during the test). The specimen is positioned in the fixture to ensure concentric loading. An extensometer is attached to the specimen gauge section and the middle portion of the specimen (the extensometer will measure changes in the length of the specimen). Recording devices are activated, and the load is applied at the prescribed rate. 

Video 01: Compression testing

Specimen size:

Specimens in Solid Cylindrical Form: It is the recommended geometry for test specimens. Three forms of solid cylindrical specimens are used, designated as short, medium-length, and long.

Rectangular or Sheet-Type Specimens: Test specimens are flat and as thick as the material, if possible. The width and length of the specimen depend upon the dimensions of the machine used.

Number of Specimens required for ASTM E9 testing: Usually, five to ten specimens should be sufficient to determine the compressive properties of a sample.

Data:

The following data is calculated in ASTM E9 testing:

1. Compressive strength:

F = P_max  /A

F = compressive strength

P_max = the maximum load

2. Engineering Stress:

σ=P/A

σ = the engineering stress, 

P = the applied, uniaxial tensile load,

A = the original cross-sectional area, mm2.

3. Engineering Strain

ε= (I – I₀ ) I₀

ε = the engineering strain, 

I = the extensometer gauge length at any time, and

I₀ = the original gauge length of the extensometer.

4. Modulus of Elasticity: