Body undergoes some deformation, it sets up some resistance to the deformation. This resistance per unit area to deformation, is called: Stress.

Stress and Deformation:

When an external force is applied to a body, it undergoes deformation. The deformation may be compressive, tensile or shear. Stress is the internal distribution of forces that balances the external forces applied to the body. It is the force per unit area acting on a body. Stress is a measure of the intensity of the internal forces acting in a body.

Types of Stress:

There are three types of stress:

1. Tensile stress: When a body is subjected to an external force that tends to stretch it, the stress produced is called tensile stress.

2. Compressive stress: When a body is subjected to an external force that tends to compress it, the stress produced is called compressive stress.

3. Shear stress: When a body is subjected to external forces that tend to slide one part of the body over another part, the stress produced is called shear stress.

Unit of Stress:

The unit of stress is the same as the unit of pressure, which is the Pascal (Pa) or Newton per square meter (N/m²).

Stress-Strain Curve:

When a body is subjected to an external force, the deformation produced in the body is measured as strain. The relationship between stress and strain is plotted as a graph, which is called a stress-strain curve. The stress-strain curve shows how the material behaves when subjected to different types of stress.

Modulus of Elasticity:

Modulus of elasticity is a measure of the stiffness of a material. It is defined as the ratio of stress to strain for a given material under a specific set of conditions. The modulus of elasticity is also known as Young's modulus.

Conclusion:

In conclusion, stress is the resistance per unit area to deformation. It is the internal distribution of forces that balances the external forces applied to the body. The stress-strain curve shows how the material behaves when subjected to different types of stress. The modulus of elasticity is a measure of the stiffness of a material.

Stress and Deformation

Stress and deformation are two important factors that are used to describe the response of a body to external forces. Stress is the measure of the internal forces that act within a body in response to an external force applied to it. Deformation is the measure of the change in shape or size of a body in response to an external force applied to it.

Stress

Stress is defined as the force per unit area that acts on a body. It is given by the formula:

Stress = Force/Area

The unit of stress is N/m2 or pascal (Pa). Stress can be of different types, depending on the type of force applied to the body. The most common types of stress are:

- Tensile stress: It is the stress that tends to pull a body apart.
- Compressive stress: It is the stress that tends to push a body together.
- Shear stress: It is the stress that tends to twist or distort a body.

Deformation

Deformation is the measure of the change in shape or size of a body in response to an external force applied to it. It is given by the formula:

Deformation = Change in length/Original length

Deformation can be of two types, depending on the nature of the change in shape or size of a body. The two types of deformation are:

- Elastic deformation: It is the deformation that is reversible and disappears when the external force is removed.
- Plastic deformation: It is the deformation that is irreversible and remains even after the external force is removed.

Stress-Strain Curve

When a body is subjected to external forces, it undergoes deformation. The relationship between stress and deformation is described by a stress-strain curve. The stress-strain curve shows how the stress changes with the deformation of a body.

Modulus of Elasticity

The modulus of elasticity is a measure of the stiffness of a material. It is defined as the ratio of stress to strain within the elastic limit of a material. The modulus of elasticity is given by the formula:

Modulus of elasticity = Stress/Strain

The unit of modulus of elasticity is N/m2 or pascal (Pa). The modulus of elasticity is a material property and varies depending on the type of material.

Conclusion

In conclusion, stress and deformation are two important factors that describe the response of a body to external forces. Stress is the measure of the internal forces that act within a body in response to an external force applied to it, while deformation is the measure of the change in shape or size of a body in response to an external force applied to it. The modulus of elasticity is a measure of the stiffness of a material and is defined as the ratio of stress to strain within the elastic limit of a material.