Define stress and strain. What are their different types?

1. The internal restoring force per unit area of a both is called stress.

\(\text{Stress} = \frac{\text{deforming force}}{\text{area}}\) \(=\frac{|\vec{F}|}{A}\)

where \(\vec{F}\)is internal restoring force or external applied deforming force.

2. Types of stress : 

• Longitudinal stress, 
• Volume stress, 
• Shearing stress.

ii. Strain : 

1. Strain is defined as the ratio of change in dimensions of the body to its original dimensions.

\(\text{Strain} = \frac{\text{change in dimensions}}{\text{original dimensions}}\)

2. Types of strain : 

• Longitudinal strain, 
• Volume strain, 
• Shearing strain.