# Shear Modulus

- The shear modulus is the initial, linear elastic slope of the stress-strain curve in shear. The shear modulus is related to the Young's modulus and Poisson's ratio for isotropic materials:

- where
*G*= shear modulus [Nm^{-2}]*E*= Young's modulus [Nm^{-2}]- ν = Poissons ratio

- The shear modulus is related to the bulk modulus and Poisson's ratio for isotropic materials:

- where
*K*= bulk modulus [Nm^{-2}]

- When ν =
^{1}/_{3},*G*= (^{3}/_{8})*E*, and*G*= (^{3}/_{8})*K*.

Shear modulus of elasticity usually is equal to torsional modulus of elasticity. Some of the test procedures are based on a torsional test of the sample.

Also known as Modulus of Rigidity and Modulus of Elasticity in Shear.

**See also: **Poissons Ratio, Young′s Modulus.

**Subjects: ** Mechanical Engineering