tau_FKZ#

PySeismoSoil.helper_hh_model.tau_FKZ(gamma: ndarray, *, Gmax: float, mu: float, d: float, Tmax: float) ndarray[source]#

Calculate the FKZ shear stress. The FKZ model is proposed in Shi & Asimaki (2017), in Equation (6), and has the following form:

                gamma^d * mu
T(gamma) = ------------------------
              1       gamma^d * mu
            ------ + --------------
             Gmax        Tmax
where:
  • T = shear stress

  • gamma = shear strain

  • Gmax = initial shear modulus

  • d = shape parameter

  • mu = shape parameter

  • Tmax = shear strength of soil

Parameters:
  • gamma (np.ndarray) – The shear strain array. Must be a 1D array. Its unit should be ‘1’, rather than ‘%’.

  • Gmax (float) – Initial shear modulus. Its unit can be arbitrary, but we recommend Pa.

  • mu (float) – Shape parameter of the FKZ model.

  • d (float) – Shape parameter of the FKZ model.

  • Tmax (float) – Shear strength of soil. Its unit should match that of Gmax.

Returns:

T_FKZ – The shear stress determined by the formula above. Same shape as x, and same unit as Gmax.

Return type:

np.ndarray