Bulk Modulus of Elasticity Definition Formula

Introduction

The bulk modulus of a material is a property that tells us how much it can be compressed under pressure. This property is important in understanding how solid materials behave when they are stretched or squeezed. It’s one of the ways that we measure the mechanical properties of solids. The bulk modulus of elasticity is a measure of how much a material’s volume will decrease when pressure is applied to it. In the case of liquids, this property varies depending on factors such as the liquid’s specific gravity and temperature.

There are different measures of a material’s elasticity, such as Young’s modulus and Shear’s modulus. The bulk elastic properties of a material are important in understanding how it responds to external pressure and how much it will compress as a result. To calculate this, we need to know the relationship between the amount of pressure applied and the resulting fractional change in volume.

Volumetric Stress

Volumetric stress is the measure of the internal force per unit area that a material experiences due to the applied pressure or external forces acting on it in all directions. In simple words, it’s the pressure applied to material from all sides.

When a force is applied to a material in a way that changes its volume, we call it the resulting stress volumetric stress. An example of this is a solid sphere placed in a fluid under high pressure. Mathematically,

S.I unit of volumetric stress is N/m² or “Pa” (Pascal) and dimensions are L^-1M¹T^-2.

Volumetric Strain

Volumetric strain is the measure of the change in volume of a material in response to applied stress or pressure. It measures how much a material’s volume changes when it is squeezed or stretched and is represented by the fractional change in volume. In simple words, volumetric strain is the degree to which a material is compressed or expanded when a force is applied to it.

If a material is subjected to a force or pressure that causes it to change in volume, then we call it the resulting deformation volume strain. In other words, volume strain is the change in a material’s volume when it is subjected to external forces that compress or stretch it.

Mathematically,

Here, the negative sign shows a decrease in volume.

Formula: Bulk Modulus of Elasticity

The formula of Bulk Modulus of elasticity is given as the ratio of volumetric stress to the volumetric strain of the given object is always constant, known as the Bulk Modulus of Elasticity.

It is represented by the “K”.

Here, the negative sign represents the decrease in volume. The bulk modulus is measured in units of pressure, such as pascals (Pa), kilopascals (KPa), or megapascals (MPa), with higher values expressed in MPa.

Characteristics of Bulk Modulus of Elasticity

The characteristics of Bulk Modulus of Elasticity are:

1. Bulk modulus of Elasticity measures how easily a material can be compressed when applied pressure.
2. It is used to find how much the body will compress under a given amount of external pressure.
3. The bulk modulus of Elasticity is independent of the shape and size of the material and only depends on its properties.
4. Materials with a high bulk modulus of elasticity are less compressible and more resistant to deformation under pressure.
5. It is related to other elastic moduli such as Young’s modulus and shear modulus, which describe different types of deformation.
6. It is an important property in materials science and engineering, as it helps to predict how materials will behave under different types of stress and strain.

Recommended Articles:

Braggs Law: Equation, Derivation, Diffraction, and Applications
Branches Of Physics: Wave Motion
Brewster’s Law: Introduction, Derivation, Application, Angle and Relation
Bridge Construction: Introduction, Project, and Materials
Bridge Rectifier: Working, Properties, Advantage and Disadvantage