Another term for shear modulus, an elastic constant for the ratio of shear stress to shear strain. The shear modulus is one of the Lamé constants. It can be expressed mathematically as follows:

μ = τ / γ = (ΔF/A) / (ΔL/L),

where
μ = Shear modulus
τ = Shear stress = ΔF/A
ΔF = Increment of shear force A = Area acted on by the shear force
γ = Shear strain = ΔL/L
ΔL = Increment of transverse displacement parallel to A L = Original length.