What is the term for the smallest area at the point of rupture of a tensile specimen divided by the original area?

The term for the smallest area at the point of rupture of a tensile specimen divided by the original area is known as the "percentage reduction of area." This metric is crucial in materials testing as it provides insight into the ductility and toughness of the material. When a specimen is subjected to tensile stress, it undergoes deformation until it finally breaks. The smallest cross-sectional area at the rupture point is compared to the original area to determine how much the material has been deformed under stress.

This measure reflects the ability of a material to sustain plastic deformation before fracture, which is critical in applications where materials are expected to endure high levels of stress or impact. A higher percentage reduction of area indicates a more ductile material, which is often preferable in applications where resistance to sudden failure is important.

The other terms mentioned, such as percentage elongation, the Izod test, and the Charpy test, relate to different properties of materials or specific testing methods rather than to the concept of reduction of area at rupture specifically. Percentage elongation assesses how much a material can stretch before breaking, while the Izod and Charpy tests are methods used to measure the impact strength of materials rather than their ductility in tensile tests.