# Compressive Stress

## What is Compressive Stress?

Compressive stress is the force that is responsible for the deformation of the material such that the volume of the material reduces. It is the stress experienced by a material which leads to a smaller volume. High compressive stress leads to failure of the material due to tension.

Compressive stress is the stress on materials that leads to a smaller volume.

When the compressive stress is applied to the materials that are brittle, these materials fracture as there is a sudden release of the stored energy. Whereas when the compressive stress is applied to the materials that are ductile, they compress and there is no failure.

There are three ways to deform a solid with the help of external force:

1. When a solid body is stretched by applying with two equal forces normal to cross-sectional area, it is known as tensile stress
2. When a solid body is compressed, restoring force is developed due to an externally applied force which is known as compressive stress.
3. When a solid body is exposed to two equal and opposite forces parallel to the cross-sectional area, the tangential force that is developed is known as tangential or shearing stress.

### Unit of Compressive Stress:

The SI unit of compressive stress is Pascal (Pa) or Nm-2.

### Formula:

Its mathematical representation is given below:

$\sigma =\frac{F}{A}$

Where,

• $\sigma$ is the compressive stress
• F is the compressive force
• A is the unit area

### Dimension:

Its dimensional formula is [ML-1T-2].

## What is Compressive Strength?

Compressive strength is defined as the maximum compressive stress that is experienced by the material before its breakdown. It is obtained by dividing the maximum load by the cross-sectional area of the material.

Compressive strength is comparatively higher for both ductile and brittle materials. Compressive strength resists compression, whereas tensile strength resists tension.

## Difference between Tensile Stress and Compressive Stress

 Tensile stress Compressive stress Tensile stress results in elongation of the solid Compressive stress results in the shortening of the solid Tensile stress is due to the application of an external stretching force Compressive stress is due to the application of external compressive force