ABSTRACT
FIGURE 6.4: Stress-strain diagram for a typical structural steel in tension.
until at point B when a considerable elongation begins to occur with a very small increase in the tensile force. This phenomenon is known as yielding of the material, and the stress at point B is known as the yield point (or yield stress). In the region BC, the material is said to become plastic. At point C, the material begins to strain harden which resists further loading increases. Thus, with further elongation, the stress increases and it reaches an ultimate stress at point D. Beyond D, further increase in the strain causes a reduction in the stress until the material breaks down at point E.
