FEBio is a nonlinear finite element solver that is specifically designed for biomechanics and biophysics applications. It offers modeling scenarios, constitutive models, and boundary conditions that are relevant to many research areas in these fields. All features can be used together seamlessly, giving the user a powerful tool for solving 3D problems in computational biomechanics. The software is open-source, and pre-compiled executables for Windows, Mac OS X, and Linux platforms are available.

FEBio features the following analysis types:

  • Nonlinear elasticity and viscoelasticity
    • Compressible solids
    • Nearly-incompressible solids (uncoupled strain energy)
    • Isotropic, transversely isotropic & orthotropic elasticity
    • Single fiber materials and continuous fiber distributions
    • Contractile elements
    • Swelling elements
    • Solid mixtures to combine multiple constitutive relations
    • Multigeneration materials
  • Rigid body mechanics
  • Multiphasic mechanics
    • Fluid flow within deformable porous solid (biphasic/poroelastic)
    • Neutral or charged solute transport within deformable porous solid
    • Osmotic effects
    • Electric potential and current
    • Chemical reactions
  • Interstitial growth mechanics
  • Heat conduction (transient or quasi-static)
  • Computational fluid dynamics
  • Fluid-Solid interaction (FSI)
  • Reaction-Diffusion (via the FEBioChem plugin)

FEBio supports steady-state static, transient quasi-static and dynamic analyses for deformable and rigid solids. In steady-state static and quasi-static analyses, the (quasi-) static response of the system is sought and the effects of inertia are ignored. In a dynamic analysis, the inertial effects are included in the governing equations to calculate the time dependent response of the system.

FEBio supports a wide range of boundary conditions to model interactions between materials that are relevant to problems in biomechanics. These include prescribed displacements, nodal forces, pressure forces, fluid pressure and flux, and effective solute concentration and flux, which may be combined to also prescribe electric potential and current. FEBio provides the ability to represent frictionless contact for elastic, viscoelastic, rigid, and multiphasic materials, as well as frictional contact for elastic and viscoelastic materials. The user may also specify a body force to model the effects of, for instance, gravity or centripetal acceleration.

FEBio is a nonlinear implicit FE solver and does not have mesh generation capabilities. Therefore the input files, which are described in detail in this document, need to be generated by preprocessing software. The preferred preprocessor for FEBio is called PreView.