Deformation of Bars:

Bars of Uniform Section

With the knowledge gained already, you will now be able to understand compute of deformations in solids because of applications of easy stresses. Let us begin along with the instance of a prismatic bar of length 'L', uniform cross section of fields A carrying an axial load 'P' as display in Figure.

Figure

Stress in the solid is within the longitudinal direction and its magnitude might be computed as

σ = Load/ Area = P/A

If the Young's Modulus of the material, E, is called, the strain induced might be calculated as

ε = σ /E= P /AE

As strain is only deformation per unit length, the total elongation of the bar is computed as

δ = ε. L =   (P/AE) L 

Therefore, Elongation δ = PL/AE

You might please remember that the strain, ε, calculated here is in the longitudinal direction and is accompanied through strains in the lateral directions also whose magnitude is given through - υε.