Creep Constitutive Models

Introduction

This FLAC3D option can be used to simulate the behavior of materials that exhibit creep (i.e., time-dependent material behavior). Creep models have been implemented in FLAC3D. These include the following:

  1. Maxwell model — A classical viscoelastic model known as the Maxwell substance.
  2. Burgers model — A classical viscoelastic model known as the Burgers substance, composed of a Kelvin model and a Maxwell model.
  3. Power model — A two-component power law model used for mining applications (e.g., salt or potash mining).
  4. WIPP model — A reference creep model commonly used in thermomechanical analyses associated with studies for the underground isolation of nuclear waste in salt.
  5. Burgers-Mohr model — A viscoplastic model combining the Burgers model and the Mohr-Coulomb model.
  6. Power-Mohr model — A viscoplastic model combining the two-component power model and the Mohr-Coulomb model.
  7. Power-Ubiqitous mdoel — A viscoplastic model combining the two-component power model and the ubiquitous-joint model.
  8. WIPP-Drucker model — A viscoplastic model combining the WIPP model and the Drucker-Prager model.
  9. WIPP-Salt model — A viscoplastic model modified from the WIPP model; includes volumetric and deviatoric compaction behavior for salt-like materials.

The models are presented in order of increasing complexity.

In addition, it is also possible for users to write their own creep constitutive models using the DLL user-defined models option described in Writing New Constitutive Models.