Question

Define different types of elastic constants?

Answer 1

Young's modulus measures the resistance of a material to elastic (recoverable) deformation under load. A stiff material has a high Young's modulus and changes its shape only slightly under elastic loads (e.g. diamond). Definition of elastic constant. : one of the constants that express the elastic behavior of a given material — compare bulk modulus, elastic limit, poisson's ratio , shear modulus, yield point, young's modulus.

Elastic Constant | Definition of Elastic

Answer 2

Answer:

Elastic constants are the parameters expressing the relation between the stress and the strain on the materials within the stress range that the materials exhibit elastic behavoiur.

Explanation:

Different types of elastic constants are as follows:

• Young's modulus
• Bulk modulus
• Rigidity modulus
• Poisson's ratio

1. Young's modulus:

According to Hooke’s law, when a body is subjected to tensile stress or compressive stress, the stress applied is directly proportional to the strain within the elastic limits of that body. The ratio of applied stress to the strain is constant and is known as Young’s modulus or modulus of elasticity.

Young’s modulus is denoted by letter “E”. The unit of modulus of elasticity is the same as the unit of stress which is megapascal (Mpa). 1 Mpa is equal to 1 N/mm2.

Young's modulus (E) = $\frac{stress}{strain}$

2. Bulk modulus:

When a body is subjected to mutually perpendicular direct stresses which are alike and equal, within its elastic limits, the ratio of direct stress to the corresponding volumetric strain is found to be constant. This ratio is called bulk modulus and is represented by letter “K”. Unit of Bulk modulus is Mpa.

Bulk modulus (K) = $\frac{Direct stress}{Volumetric strain}$

3. Rigidity modulus:

When a body is subjected to shear stress the shape of the body gets changed, the ratio of shear stress to the corresponding shear strain is called rigidity modulus or modulus of rigidity. It is denoted by the letters “G” or “C” or “N”. Unit of rigidity modulus is Mpa.

Rigidity modulus (G) = $\frac{Shear stress}{Shear strain}$

4. Poisson's ratio:

When a body is subjected to simple tensile stress within its elastic limits then there is a change in the dimensions of the body in the direction of the load as well as in the opposite direction. When these changed dimensions are divided with their original dimensions, longitudinal strain and lateral strain are obtained.

Poisson's ratio (μ) = $\frac{Lateral stress}{Longitudinal strain}$