Elastic Constants – Young’s Modulus, Modulus of Rigidity and Bulk Modulus

In this article you will learn about the Elastic Constant – Young’s modulus, Modulus of rigidity and Bulk modulus. We will also
discuss about the difference between Young’s modulus, Modulus of rigidity and
Bulk modulus.

Elastic Constants – Young’s Modulus, Modulus of Rigidity and Bulk Modulus

The various elastic constants in strength of materials are
  1. Young’s modulus or modulus of elasticity
  2. Modulus of rigidity or Shear Modulus
  3. Bulk Modulus
Let’s discuss about them one by one

Young’s Modulus

Definition: It is defined as the ratio of tensile
stress or compressive stress to the corresponding strain within elastic limit. It
is denoted by symbol E. It is also known as modulus of elasticity or elastic modulus.
Elastic Constants – Young’s Modulus

Where

E = Young’s Modulus
σ = Tensile or compressive stress
e = Tensile or compressive strain
  • The SI unit of Youngs modulus is N/mm2.

Modulus of Rigidity

Definition: It is defined as the ratio of shear stress to
corresponding shear strain within elastic limit. It is also known as shear modulus. It
is represented by C or G or N.

Modulus of Rigidity

Where
τ = Shear stress
ɸ = Shear strain
  • The SI unit of C is N/mm2

Bulk Modulus

Definition: It is defined as the ratio of direct stress to the
corresponding volumetric strain within elastic limit. It is denoted by K.

Bulk Modulus

σ = Direct stress
(dV/V) = Volumetric strain
  • The SI unit of C is N/mm2

Difference Between Young’s Modulus, Modulus of Rigidity and Bulk
Modulus.

S.no
Young’s Modulus
Modulus of Rigidity
Bulk Modulus
1.
It is the ratio of tensile or compressive stress to the corresponding
strain within elastic limit.
It is the ratio of shear stress to the corresponding shear strain within
elastic limit.
It is the ratio of direct
stress to the corresponding volumetric strain within elastic limit.
2.
It is denoted by E.
It is denoted by C or G or N.
It is denoted by K.
3.
E = stress/ strain
C = shear stress/shear strain
K = direct stress/ volumetric strain.
This is all about the Elastic constant – Young’s modulus, modulus
of Rigidity and Bulk modulus. If you find anything missing or incorrect than
comment us. And if you find this article informative and useful than don’t forget
to like and share us.

Pankaj Mishra

Pankaj Mishra is a blogger by passion and Mechanical Engineer by profession. He has completed his B.Tech degree in mechanical engineering in the year 2015. He loves to share his knowledge and help others.

One thought on “Elastic Constants – Young’s Modulus, Modulus of Rigidity and Bulk Modulus

Leave a Reply

Your email address will not be published. Required fields are marked *