What Properties do Stress-Strain Diagrams Illustrate?
Ductile materials will have a far longer plastic deformation zone than brittle materials, as shown in the figure below. The specimen continues to hold load because the plastically deformed material undergoes strain hardening. Ductile materials will also exhibit significant narrowing at one portion of the specimen as the length increases until rupture occurs. Read on Tensile Testing of Engineering Materials Mechanics of Materials Strain Gauge Installation Methods A stress-strain curve can also be used to determine the yield strength of a specimen. Yield strength is defined at the stress level at which the part achieves a 0.2% permanent deformation, as shown in the figure below. Stress-strain curves exist for a variety of materials and alloys, allowing engineers to select the right material for their particular application. Source Beer, F., Johnston, E.R., Mechanics of Materials, Second Edition, McGraw-Hill, 1992.
