Given stress strain diagram for a ductile material in tensio

Given stress- strain diagram for a ductile material in tension, determine the points or regions on the curve:

Solution

A:[a] Point A is the proportional limit. Upto this point stress is diectly proportional to strain as indicated by the straight line OA of the curve.

I:[i]   Point I is the yield point, beyond this point there will be some permanent deformation in the material. The yield point determines the limits of performance for mechanical components.

D:[d] Point D is ultimate stress point. This point is a measure of the maximum strength that the material has to bear stress before breaking.

E:[e] Point E is the breaking point. It is the strength of material at rupture.

OF:[o] Region OF is the elastic region. In this region of the stress-strain curve the material returns to its undeformed state when applied forces are removed.

FG:[f] Region FG is the plastic region. It is the region in which the material deforms permanently.