tau_MKZ#

PySeismoSoil.helper_mkz_model.tau_MKZ(gamma: ndarray, *, gamma_ref: float, beta: float, s: float, Gmax: float) → ndarray[source]#

Calculate the MKZ shear stress. The MKZ model is proposed in Matasovic and Vucetic (1993), and has the following form:

                      Gmax * gamma
T(gamma) = ---------------------------------------
              1 + beta * (gamma / gamma_ref)^s
where:

  • T = shear stress

  • gamma = shear strain

  • Gmax = initial shear modulus

  • beta = a shape parameter of the MKZ model

  • gamma_ref = reference strain, another shape parameter of the MKZ model

  • s = another shape parameter of the MKZ model

Parameters:

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

  • gamma_ref (float) – Reference shear strain, a shape parameter of the MKZ model. Unit: 1.

  • beta (float) – A shape parameter of the MKZ model.

  • s (float) – A shape parameter of the MKZ model.

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

Returns:

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

Return type:

np.ndarray