The elastic moduli relevant to polycrystalline material are Young’s Modulus of Elasticity, the Shear Modulus of Elasticity, and the Bulk Modulus of Elasticity.
Young’s Modulus of Elasticity is the elastic modulus for tensile and compressive stress and is usually assessed by tensile tests. Young’s Modulus of Elasticity is discussed in detail in the preceding chapter.
The Shear Modulus of Elasticity is derived from the torsion of a cylindrical test piece. Its symbol is G.
The Bulk Modulus of Elasticity is the elastic response to hydrostatic pressure and equilateral tension or the volumetric response to hydrostatic pressure and equilateral tension. It is also the property of a material that determines the elastic response to the application of stress.