Bases: ContactLawBase
Stress dependent stiffness for the contact law based on Chang et al. (1989).
\[
k_n=k_{n0}\left(\frac{f_n}{f_ref}\right)^{n_e}, k_t=k_n k_{rR}
\]
Required material parameters:
kn0: (reference) normal stiffnessne: an exponent in the nonlinear normal stiffnesskrr: a constant ratio between normal and shear stiffnessfref: a reference force
References
- Chang, C.S., Sundaram, S.S., Misra, A., 1989. Initial moduli of particulate mass with frictional contacts. International Journal for Numerical and Analytical Methods in Geomechanics 13 (6), 626–641.
elasticStiffness(
idx: int, fn: float, sv0: StateVariable, sv: StateVariable
) -> ndarray
Bases: ContactLawBase
Constant stiffness for the contact law.
\[
k_t = k_{t0}, k_n = k_{t0} R
\]
Required material parameters:
kn0: (reference) normal stiffnesskrr: a constant ratio between normal and shear stiffness
elasticStiffness(
idx: int, fn: float, sv0: StateVariable, sv: StateVariable
) -> ndarray
Bases: ContactLawBase
Stress dependent stiffness for the contact law based on Richart et al. (1970).
\[
k_t = k_{t0} \frac{(2.97-e)^2}{1+e}\left(\frac{f_n}{P_{at}}\right)^{n_g}, K_n = G_0 R
\]
Required material parameters:
kn0: (reference) normal stiffnesskrr: a constant ratio between normal and shear stiffnessng: an exponent in the nonlinear shear modulus
References
- Richart, F. E., Hall, J. R., and Woods, R. D. (1970). Vibrations of Soils and Foundations. Prentice Hall, Upper Saddle River, NJ, USA.
elasticStiffness(
idx: int, fn: float, sv0: StateVariable, sv: StateVariable
) -> ndarray