Elastic Moduli Relation Sigma — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Elastic Moduli Relation for Poisson's Ratio This relationship is valid for isotropic, linear elastic materials subjected to small strains, connecting Poisson's ratio to the Bulk and Shear moduli. Start with the definition of Poisson's ratio, = - trans axial . Use the general relationship linking Young's Modulus (Y), Bulk Modulus (B), and Shear Modulus ( ). Substitute the expressions for Y, B, and into the ratio defining . Algebraically simplify the resulting expression to eliminate Young's Modulus (Y) and obtain the final form. B > 0 0 [-1, 1] Confusing Poisson's ratio ( ) with the ratio of moduli (e.g., /B ). Assuming the relationship holds for non-linear or viscoelastic materials. Forgetting that the ratio of moduli must be positive, which constrains the possible values of .