An equivalent stress calculated from the complete stress state. For ductile metals, yielding is predicted when the Von Mises stress reaches the material's yield strength.
σᵥ = √[ ((σ₁−σ₂)² + (σ₂−σ₃)² + (σ₃−σ₁)²) / 2 ]. Compare the resulting equivalent stress with the material yield strength after applying the project\'s safety factor and design-code requirements.
A yielding criterion based on the maximum shear stress in the material. Yielding is predicted when the maximum principal stress difference reaches the uniaxial yield strength.
σₜ = max(|σ₁−σ₂|, |σ₂−σ₃|, |σ₃−σ₁|). Compare the resulting equivalent stress with the material yield strength after applying the project\'s safety factor and design-code requirements.
Von Mises and Tresca are both commonly used for ductile-material design. Von Mises gives a smooth, direction-independent equivalent stress, while Tresca directly limits maximum shear stress.
Tresca prediction ≤ Von Mises prediction in conservatism. Compare the resulting equivalent stress with the material yield strength after applying the project\'s safety factor and design-code requirements.