Fracture Mechanics: Griffith Criterion

A crack propagates when the strain energy release rate G exceeds the surface energy 2γ. Griffith's criterion: σ_c = √(2Eγ/πa). Visualize the energy balance, stress field, and crack growth.

Applied stress σ σ = 2.00 Crack half-length a a = 3.00 Young's modulus E E = 10 Surface energy γ γ = 1.00

G = πσ²a/E | G_c = 2γ | σ_c = √(2Eγ/πa) | K_I = σ√(πa)