* now remembering stiffness similar to how we do it for Lp etc.; avoids undefined stiffness values for nonconverged stiffness calculation
* non-local stuff:
* changed non-local kinetics (Gilman2002)
* enforce zero shearrate for overall carrrier density below relevant density
* enforce zero density for those states that become negative and were below relevant density before
* dislocation velocity is not limited by V^(1/3) / dt anymore
--> new "crystallite" part in config file
--> new "crystallite" option for microstructures
--> new output file "...job.outputCrystallite" to be used in conjunction with marc_addUserOutput for meaningful naming of User Defined Vars.
- reworked contribution of immobile dislocation density for rate equations
- flux is now calculated on the basis of interpolated velocities and densities at the interface; both incoming and outgoing fluxes are considered, so every material point only changes his own dotState
- dislocation velocity is now globally defined and calculated by subroutine constitutive_nonlocal_kinetics; the subroutine is called inside _LpAndItsTangent as well as _microstructure; therefore, microstructure now needs Tstar_v as additional input; in the future one should perhaps create a subroutine constitutive_kinetics that calls constitutive_nonlocal_kinetics separately, to clearly distinguish between microstructural and kinetic variables
- better use flux density vector as output variable instead of scalar flux values for each interface
- added output variables internal and external resolved stress
crystallite:
- added flag to force local stiffness calculation in case of nonlocal model
- misorientation angle is explicitly set to zero when no neighbor can be found
debug:
- added flag "selectiveDebugger" that is used when debugging statements should only affect a specific element, ip and grain; these are specified with the new variables debug_e, debug_i and debug_g
- debugger can now be used in its original sense
The calculation of the misorientation is now done once in crystallite init and at the end of every FE increment. This saves a lot of time compared to doing it in dotState for every crystallite subinc.
(1) subStepSizeHomog and subStepSizeCryst := size of substep when cut-back is applied (initially was hard-coded).
(2) stepIncreaseHomog and stepIncreaseCryst := step increase when calculation for substep converge (was also hardcoded).
introduced a possibility to choose different finite difference scheme, i.e., forward-, backward- and central-difference, for computing grain numerical tangent. note that central-difference scheme will slow down the computation significantly. please use it only if necessary.
parameters to set these new features have been included in numerics.f90 and numerics.config, whereas corresponding error messages have been introduced in the IO.f90
- read in activation energy for dislocation glide from material.config
- changed naming of dDipMin/Max to dLower/dUpper
- added new outputs: rho_dot, rho_dot_dip, rho_dot_gen, rho_dot_sgl2dip, rho_dot_dip2sgl, rho_dot_ann_ath, rho_dot_ann_the, rho_dot_flux, d_upper_edge, d_upper_screw, d_upper_dot_edge, d_upper_dot_screw
- poisson's ratio is now calculated from elastic constants
- microstrucutre has state as first argument, since this is our output variable
- periodic boundary conditions are taken into account for fluxes and internal stresses. for the moment, flag has to be set in constitutive_nonlocal.
- corrected calculation for dipole formation by glide
- added terms for dipole formation/annihilation by stress decrease/increase
constitutive:
- passing of arguments is adapted for constitutive_nonlocal model
crystallite:
- in stiffness calculation: call to collect_dotState used wrong arguments
- crystallite_postResults uses own Tstar_v and temperature, no need for passing them from materialpoint_postResults
homogenization:
- crystallite_postResults uses own Tstar_v and temperature, no need for passing them from materialpoint_postResults
IO:
- changed error message 229
material.config:
- changed example for nonlocal constitution according to constitutive_nonlocal
all:
- added some flush statements
crystallite does not accelerate anymore, since, typically, longer step immediately fails and uses resources in vain. (future: remember number of successful steps to increase step size after x of those...)
homogenization.f90 and crystallite.f90 >>> Correction in the algorithm to count the iteration distribution (for better statistics).
material.config and numerics.config >>> more collection of parameters.
constitutive_phenopowerlaw.f90 >>> adding new parameter: constitutive_phenopowerlaw_w0_slip, i.e., the hardening rate exponent.
homogenization.f90 >>> most important change is to add an if-else statement (line 379-380) to switch crystallite_requeted = .false. for already converged material point iteration (el/ip). the rest of the changes are cosmetics and debugging stuffs.
crystallite.f90 >>> similar to homogenization.f90, the most important change is to add additional if-else statement (line 574) in the jacobian (perturbation) loop. now the jacobian calculation will only be performed when crystallite_requested = .true.. the rest is only cosmetic.
- completed postResults output function
- connecting vector of neighboring material points is mapped to intermediate configuration of my neighbor
crystallite.f90
- zero out dotState only when crystallite is non-finished
- set nonfinished flag to false if crystallite is not on Track after state update
- in updateState: set onTrack flag to false if encounter NaN
- removed some old debugging outputs and added others
homogenization.f90
- in debugging mode now telling when a cutback happens
debugging memory leak closed
debugging counters corrected
center of gravity stored in mesh
state updated is now split into a collecting loop and an execution
updateState and updateTemperature fill sequentially separate logicals and evaluate afterwards to converged
added 3x3 transposition function, norm for 3x1 matrix and 33x3 matrix multiplication in math
non-converged crystallite triggers materialpoint cutback (used to respond elastically)
non-converged materialpoint raises terminal illness which in turn renders whole FE increment useless by means of odd stress/stiffness and thus waits for FE cutback
# non-greedy memory allocation
# generation of outputConstitutive to allow for script-based T16 extraction
# exchange of phenomenological by more general phenopowerlaw
# lattice is based on slip and twin families which can be treated as individual entities (switched on/off, separate hardening, etc.)
# nicer debugging output
# changed some error/warning codes
# plus potentially some minor additional brushes here and there
Christoph Kords