Linearized Mohr failure line

Input(s)

$S_{o}$: Stress (psi)

$\sigma_{n}$: Normal Stress (psi)

$\mu_{i}$: Coefficient of internal Friction $(\mathrm{cP})$

Output(s)

$\tau$: Shear Stress (psi)

Formula(s)

$$ \tau=\mathrm{S}_{\mathrm{o}}+\sigma_{\mathrm{n}} * \mu_{\mathrm{i}} $$

Reference(s)

Mark D. Zoback, Reservoir Geomechanics, Cambridge University Press, UK, Page: 89.