FEBio 4.6
New Features:
- Two new rigid constraints were added to prescribe the rotation of a rigid body: rigid_rotation_vector prescribes the rotation via a rotation vector. The rigid_euler_angles prescribes the rotation via Euler angles.
- Added "moving frame" body load, which can be used to emulate the effects of being embedded in an accelerating and rotating coordinate system.
- Added new weak bond recruitment functions for reactive viscoelastictiy, including Weibull, log-normal, quintic, and gamma. Added new damage CDF function gamma.
- Added filtering capabilities for RVE generations, RVE bonds, RVE recruitment and RVE strain, to plot these variables for specific solid mixture constituents
- Added some initial support for body forces for beams. (Will only work with constant body forces.)
- Added "field" plot variable, which can be used to output any field variable. Field variables are the internal solution variables that FEBio solves for. The available field variables depend on the physics module.
- Added "rotation" plot variable, which writes the nodal orientation of beam elements.
- Added Lagrange multiplier method to linear constraints in FEAugLagLinearConstraint
Improvements:
- Array variables (e.g. solute concentrations) are now exported as FIELD variables in VTK export.
- Added units to rigid force and mixture normal traction
- Added option to use solute/sbm name in concentration dofs.
- For dynamic analysis, the initial accelerations are now calculated based on the applied loads at time 0. This may improve the accuracy and convergence for dynamic problems.
- Added initial values for some of the discrete Hill material parameters.
- Modified mixture stress plot variable so that you can specify the material as well as the solid component.
- Added additional plot variables for discrete element length and direction.
- Added option to turn off deprecation warnings. These are now turned off for older file formats.
- Simplified implementation of (uncoupled) fiber-exp-linear a bit.
- Costly evaluations of the zero stiffness matrix contributions of constant body forces are now avoided, which may significantly speed up models that use constant body forces.
- Discrete domains are now processed after they have been read in, which is more efficient.
- Improved memory management of the dump stream used during serialization.
- Modified fiber-exp-linear models to optionally enforce continuity of the strain energy density and elasticity when the user sets c3=0.
- Changed default value of tolerance parameter to 0.1 in FEThermoFluidPressureLoad
- Added units to 'orthotropic elastic' and 'orthotropic CLE' materials
- Modified 'recruitment user' to use 'function' instead of 'cdf' for the recruitment function.
- Modified reactive viscoelastic and uncouple reactive viscoelastic materials to use 'bond recruitment' functions instead of 'damage CDF' functions. Modified the weak bond recruitment algorithm from published paper formula to accommodate strain reversal in cyclical loading.
- Added support for writing FMT_MULT mesh data to plot file.
- Added check to make sure that the value of int parameters is indeed a number. If not, an exception is thrown.
- Changed type for FEThermoFluidPressureLoad from 'fluid pressure' to 'fluid pressure constraint'
- Added additional scenarios for material test.
- Improved calculation of incomplete Gamma function needed for the evaluation of the Malkin reduced relaxation function. Limited the range of the Malkin exponent to be >= 1
- Plotfile is now created after model has been initialized. This allows some of values calculated during initialization to be stored in the plot file (e.g. initial discrete element force).
- Now using full Newton in tangent diagnostic, which seems to work a bit better.
- Updated FEThermoFluidPressureLoad to include penalty, augmented Lagrangian, Lagrange multipler methods.
Bug fixes:
- Fixed bug in contact potential initialization.
- Fixes some issues to the velocity calculations in the biphasic and multiphasic solvers.
- Fixed several issues with rigid body dynamics.
- Fixed issue with surface data map that caused crash with cold restart.
- Fixed problem with processing const surface data. Also provided more accurate error message when bc type is not recognized.
- Fixed additional issue with reading old 2.5 files.
- Fixed some issues with serialization of some material point data classes.
- Fixed issue with merging maps for vec3d mesh data.
- Fixed issue that was preventing old 2.5 files from running.
- Fixed the reactive viscoelastic material response when weak bond recruitment is included, so that the response remains physical and meaningful during strain reversal, such as cyclical strain or cyclical stress
- Fixed and updated several material parameter units.
- Fixed strain energy density calculation for fiber-exp-linear when a non-zero c3 is specified by the user, to enforce continuity of the strain energy density.
- Fixed bug that caused a crashed when plot file type was not initialized.
- Fixed problem with restart when using VTK plot files.
- Fixed some problems with serialization of model parameters.
- Fixed cause of crash when using body forces with the rigid shell domain.
- Fixed FEThermoFluidPressureLoad to make prescribed pressure spatially variable
- Fixed implementation of nonlinear constraints in the fluid solver, thermofluid solver, and polar fluid solver.
- Fixed issue with reading body loads that was always activating the loads, regardless of what step they are defined in.
Documentation:
- Added description of dump_stride command line option and made some minor formatting changes to the febio command line section.
- Updated user manual entry for uncoupled fiber-exp-linear and corrected formula for C6 in user manual .
- Modified User Manual to describe continuous strain energy density for fiber-exp-linear and uncoupled version.
- Updated User Manual to describe optional enforcement of strain energy density and elasticity continuity in fiber-exp-linear materials.
- Minor edits to nonlinear constraints section of Theory Manual, such as adding equations numbers.
- Updated Theory Manual to display representative continuous relaxation spectra and corresponding reduced relaxation functions
- Fixed typo in Holmes-Mow material.
- Updated theoretical description of nonlinear constraint enforcement.