FLAC3D is a numerical modeling code for advanced geotechnical analysis of soil, rock, and structural support in three dimensions.
FLAC3D is used in analysis, testing, and design by geotechnical, civil, and mining engineers. It is designed to accommodate any kind of geotechnical engineering project where continuum analysis is necessary. FLAC3D utilizes an explicit finite difference formulation that can model complex behaviors not readily suited to FEM codes, such as: problems that consist of several stages, large displacements and strains, non-linear material behavior and unstable systems (even cases of yield/failure over large areas, or total collapse).
Dynamic Options: The dynamic analysis option permits three-dimensional, fully dynamic analysis with FLAC3D. User-specified acceleration, velocity, or stress waves can be input directly to the model either as an exterior boundary condition or an interior excitation to the model. FLAC3D contains absorbing and free-field boundary conditions to simulate the effect of an infinite elastic medium surrounding the model
This option can be coupled to the structural element model, thus permitting analysis of soil-structure interaction brought about by ground shaking. The dynamic feature can also be coupled to the groundwater flow model. This allows, for example, analyses involving time-dependent pore pressure change associated with liquefaction. The dynamic model can likewise be coupled to the optional thermal model in order to calculate the combined effect of thermal and dynamic loading. The dynamic option extends FLAC3D's analysis capability to a wide range of dynamic problems in disciplines such as earthquake engineering, seismology, and mine rockbursts.
Creep Options: This option can be used to simulate the behavior of materials that exhibit creep (i.e., time-dependent material behavior). There are eleven available material models (Maxwell model, Burgers model, Power model, WIPP model, Burgers-Mohr model, Power-Mohr model, Power-Ubiquitous model, WIPP-Drucker model, Soft-Soil-Creep model, WIPP-Salt model and Columnar-Basalt (COMBA) Mode) in FLAC3D that simulate viscoelastic and viscoplastic (creep) behavior.
A FLAC3D grid can be configured for both a creep calculation and a dynamic 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.
Thermal Options: The thermal option of FLAC3D incorporates both conduction and advection models. The conduction models allow simulation of transient heat conduction in materials, and the development of thermally induced displacements and stresses. The advection model takes the transport of heat by convection into account; it can simulate temperature-dependent fluid density and thermal advection in the fluid.
User-Defined Constitutive Models: You may create your own user-defined constitutive model (UDM) for use in FLAC3D. The model must be written in C++ and compiled as a DLL file, and can be loaded whenever needed or loaded automatically if placed in the “exe64\plugins\models” folder. The main function of the constitutive model is to return new stresses, given strain increments.