Rationale

Tensile testing is a destructive test designed to explore the full deformation range of engineering material samples. The test samples have geometries recommended by the American Society for Testing and Materials (ASTM) and may have either rectangular or circular cross sections. They are held in the grips of a testing machine, such as the 8501 Instron apparatus, that is capable of applying a controlled deformation pattern and measuring the associated loads and sample length changes. This information is then converted into a stress/strain curve for the sample. Either Engineering (Nominal) stress and strain, or True stress and strain may be computed from the test data.

Characteristic features of the stress/strain curve permit the determination of quantities such as the Elastic Modulus, the Proportional Limit, the Yield Point, the Ultimate Tensile Strength, and the strains associated with yield, the limit of uniform strain, and with fracture. These quantities are used to evaluate a materials' mechanical performance. Their values may not be independent of the test conditions, and test parameters such as the strain-rate and temperature should be noted together with other test data.