ABSTRACT
For a given external or internal force, the smaller the area of the member resisting the force, the higher the stress.
Normal stress is defined as the intensity of force or the force per unit area acting normal to the area of a member. It is expressed as:
σ lim ∆A→0
∆ ∆
A
P (6.1)
where ∆A is an element of area and ∆P is the force acting normal to the area ∆A. When the normal stress tends to ‘pull’ on the area, it is called tensile stress and if it tends to ‘push’ on the area, it is termed compressive stress.
