Tensile Testing

Tensile or tension testing is a fundamental and most commonly used test for the characterization of the mechanical behavior of materials. The test consists of pulling a sample of material and measuring the load and the corresponding elongation. Main properties measured from the test include Young’s modulusYoung’s modulus, yield, ultimate and breaking strength, ductilityDuctility, resilienceResilience, tensile toughnessTensile toughness and Poisson’s ratioPoisson’s ratio. The tensile properties are used in selecting materials for engineering applications and in research and development of new materials or processes. In this chapter we will present the basic characteristics of the time-independent tensile test. More specifically, we will discuss the testing procedure, the specimen characteristics, the engineering and true stress–strain curves, the yield and strain hardening behavior, the hysteresis loopHysteresis loop in plastic deformation, the Bauschinger effectBauschinger effect, the state of stressStress in the neck area, the approximate McGregor methodMcGregor method, idealized and analytical expressions of stress–strain curves, the definitions of ductility, resilienceResilience and tensile toughnessTensile toughness, the Poisson’s ratioPoisson’s ratio, the bulk modulusBulk modulus, and standards for the tensile test. Finally, we will present values of material properties obtained from the tension test for some engineering metals and polymers.