nominal stress and true stressnominal stress is

Question

Nominal Stress and True Stress:

Nominal stress is the ratio of force per initial cross sectional area (original area of cross section).

Nominal stress = Force / initial area of cross-section  =  P / A₀

True stress is ratio of force per actual cross sectional area taking lateral strain into consideration.

True stress = Force / Actual area of cross-section = P /A