27.6 SHEAR STRAIN
À pWhile Young's modulus is intended for the stress to strain relationship for Axial or normal strain, we will use the Shear modulus G for shear strain.
First consider the general square cubic element below,
Now, Assume a shear stress in the positive x direction that induces the deformation as shown below.
NOTE: these calculations are based upon the assumption of small angles of deflection.
How a material strains in shear is related to normal strain by Poisson's Ratio,
Consider the example shown below from Beer and Johnson, 1992, pg. 89 #2.86,