ABSTRACT
Stress and strain are the fundamental considerations for any mechanical application. The stress-strain curve for materials is developed by loading test specimens (often called dog bone specimen) in accordance with American Society for Testing and Materials (ASTM) or Deutsche Industrie Norm (DIN) procedures. The stress-strain curve can be used to read off the structural load-bearing capability (sometimes called loadability) of a certain material. Loadability is one of the most critical material properties when it comes to selecting the most suitable material for an application. Loadability is tested in a standardized tensile test with a procedure defined by ASTM or DIN standards (Figure 3.1). The overall length of the plate specimen is usually around 8 inches and width 0.5 inch. The thickness is about 0.005 inch. The gage length is 2 inches and the width in the gap section is about 0.75 inch. The basics of the test include slowly and steadily pulling the test specimen in tension until the specimen fractures under the applied load. Different materials behave in different ways. So, using this standardized test, engineers can compare different materials based on each material's stress-strain curve (test results).
