Stress-Strain Curve

A plot of stress versus strain generated during a uniaxial tensile or compression test from which the values of yield strength, ultimate strength, percent elongation and in some cases elastic modulus can be determined. The most common types of stress-strain curves are referred to as “engineering,” “true,” or “cyclic.” The engineering type is used most often in the wire industry because the curve can be generated with less information. The true type is more accurate, but is only used for advanced analysis, such as in determining working limits for complex deformations. A cyclic curve uses the same basic calculations as the engineering type, but load is repeatedly applied and released from the material for use in fatigue studies.A graph in which stress (load divided by the original cross sectional area of the test piece) is plotted against strain (the extension divided by the length over which it is measured).