Balandin criterion

For Balandin criterion, analysis is performed according to the following formula:

 

σ_Balandin = 3 * (1 - X) * σ_A + L * σ_i**2

 

 

σ_A = 1/2 ⋅ (σ₁ + σ₂)

 

X = σ_u,t / σ_e,c

 

L = 1 / σ_e,c

 

Where:

σ_Balandin  – Balandin stress criterion;

σ_i – intensity of stress;

σ_A – average stress (hydrostatic pressure);

σ₁, σ₂  – principal stresses, σ₁ ≥ σ₂;

σ_e,c  – ultimate compression;

σ_u,t  – ultimate tension.