For linear elastic materials, stress is linear in strain: σ_{ij} = C_{ijkl} ε_{kl}, where the stiffness tensor C has up to 21 independent components for the most general anisotropic material, reducing to 2 (Lamé λ, μ) for isotropic media.
For linear elastic materials, stress is linear in strain: σ_{ij} = C_{ijkl} ε_{kl}, where the stiffness tensor C has up to 21 independent components for the most general anisotropic material, reducing to 2 (Lamé λ, μ) for isotropic media.