axial σ = N/A τ = V/A Hooke's law, stress-strain curves σ = Eε τ = Gγ stress transformations strain transformations ε = δ/L δ = NL/EA + αΔTL φ = TL/GJ M = EI d2y/dx2 torsion τ = Tc/J flexure σ = -My/I shear τ = VQ/Ib pressure σ = pr/t σ = pr/2t