Once data have been collected, the tensile stress developed and the resultant strain can be calculated. Stress is calculated based on the applied load and original cross-sectional area. Strain is the change in length divided by the original length. Principal properties determined through tensile testing include yield strength, tensile strength, ductility (based on the percent elongation and percent reduction in area), modulus of elasticity, and visual characteristics of the fracture. For brittle materials, which do not show a marked yield or ductility, data is collected for tensile strength and type and condition of fracture.
Tensile Strength - The maximum tensile stress that a material is capable of developing during a test.
Stress - The intensity of the internally-distributed forces or components of forces that resist a change in the form of a body. The three basic types of stress are tension, compression, and shear. The first two, tension and compression, are called direct stresses.
Elastic Limit - The greatest amount of stress a material can develop without taking a permanent set.
Percent Elongation - The total percent strain that a specimen develops during testing.