# Types of Stress and Strain

### Tensile Stress and Strain:-

When a body is subjected to two equal and opposite axial pulls, as a result of which the body tends to extend to decrease its length, the stress and strain-induced are known as tensile stress and tensile strain.

#### Compressive Stress and Strain:-

When a body is subjected to two equal and opposite axial pushes, as a result of which the body tends to decrease its length, the stress and strain-induced are known as compressive stress and compressive strain.

#### Young’s Modulus or Modulus of Elasticity:-

Hooke’s law state that when a material is loaded within the elastic limit, the stress is directly proportional to strain, i.e.

σ α ε  ⇒   σ = E.ε     or    E = σ / ε  = P x l / A x ∂l

Where E is a constant of proportionally and is known as Young’s Modulus or Modulus of elasticity.

##### Shear Stress and Strain:-

When a body is subjected to two equal and opposite forces, acting tangentially across the resisting section, as a result of which the body tends to shear off the section, then the stress-induced is called shear stress. The corresponding strain is known as shear strain and it is measured by the angular deformation accompanying the shear stress.

###### Shear Modulus or Modulus of Rigidity:-

It has been found experimentally that within the elastic limit, the shear stress is directly proportional to the shear strain.

Mathematically,…

ℑ α Φ   or  ℑ = C.Φ     or  ℑ/Φ = C

Where,  ℑ= Shear stress;  Φ= Shear strain,  and C= Constant of proportionally, known as a shear modulus to shear modulus or modulus of rigidity. It is also denoted by  N or G.