This option can be used to simulate the behavior of materials that exhibit creep (i.e., time-dependent material behavior).
There are ten available material models in FLAC2D that simulate viscoelastic and viscoplastic (creep) behavior:
- Maxwell model — A classical viscoelastic model known as the Maxwell substance.
- Burgers model — A classical viscoelastic model known as the Burgers substance, composed of a Kelvin model and a Maxwell model.
- Power model — A two-component power law model used for mining applications (e.g., salt or potash mining).
- WIPP model — A reference creep model commonly used in thermomechanical analyses associated with studies for the underground isolation of nuclear waste in salt.
- Burgers-Mohr model — A viscoplastic model combining the Burgers model and the Mohr-Coulomb model.
- Power-Mohr model — A viscoplastic model combining the two-component power model and the Mohr-Coulomb model.
- Power-Ubiquitous model — A viscoplastic model combining the two-component power model and the ubiquitous-joint model.
- WIPP-Drucker model — A viscoplastic model combining the WIPP model and the Drucker-Prager model.
- Soft-Soil-Creep model — A soft soil model considering the time-dependent secondary compression.
- WIPP-Salt model — A viscoplastic model modified from the WIPP model; includes volumetric and deviatoric compaction behavior for salt-like materials.
All ten models are available with the creep option. A FLAC2D grid can be configured for both a creep calculation and a dynamic (option) calculation. However, both models are generally not used simultaneously because of the widely different timesteps. In addition, it is also possible for users to write their own creep constitutive models using the C++ UDM option.