Basic material properties are critical for design and performance assessment
While tension and compression testing are two of the most basic types of testing for material properties, they are also two of the most useful. This basic material property data is critical for component design and service performance assessment. Typical analytical information derived from tension and compression testing includes the following: compressive strength, elastic limit, elongation, modulus of elasticity proportional limit, reduction in area, strain, yield point, yield strength, and ultimate tensile strength.
Typical test applications and the development areas they support can include:
- The determination of tensile/compression properties of raw material to compare to documented material specifications;
- Experimental material property data for finite-element modeling or other product design to determine desired mechanical behavior and service duty cycles;
- Estimation of component mechanical performance by duplicating the expected service environment.
Important test sample requirements for testing
Standard tensile and compression tests on metals and plastic use specially-prepared test specimens. These specimens can be machined cylindrical samples or flat plate samples (often called a dogbone), and have a specific ratio of length to width-diameter in the test area (gage) in order to comply with standard ASTM/ISO testing standards. Cylindrical and tubular geometries, fibers, and wires are tested directly using specially designed fixtures with optimized gripping and failure location.
The most common specimen geometry is a right circular cylinder with flat/parallel ends. Other shapes are used but typically require special fixtures to avoid buckling, etc. Component testing or service simulation testing depends on the specific test machine/configuration to be used.
Biological samples often require testing in their found condition although it is not uncommon to machine smaller samples from specific areas (e.g. bone) of interest. Small-scale testing often doesn’t conform to established standards and the test engineer is left to devise the specimen geometry, gripping method and proper test equipment sizing (i.e. low force) to get optimized, repeatable results.
A variety of Bose® ElectroForce® test instruments have been utilized for effective tensile and compressive testing as part of a comprehensive product design or research program.