* 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
mesh:
elemType identification based on lower case
Abaqus now reports more errors
IO:
new function to inquire whether inputfile contains "parts"
new function to assemble multiply included inputfile into a flat one
awareness of range generation in element numbers
error reporting
--> 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.
- corrected flux term
- multiplication is now aware of dislocation type
- corrected change rate for "dipole size" dupper
- corrected term for dipole dissociation by stress change
- added transmissivity term in fluxes which accounts for misorientation between two neighboring grains (yet hardcoded transmissivity according to misorientation angle)
- added more output variables
constitutive:
- 2 additional variables "previousDotState" and "previousDotState2", which are used to store the previous and second previous dotState (used in crystallite for acceleration/stabilization of state integration)
- timer for dotState now measures the time for calls to constitutive_ collectState (used to reside in crystallite_updateState, which is not critical in terms of calculation time anymore)
crystallite:
- convergence check for nonlocal elments is now done at end of crystallite loop, not at the beginning; we simple set all elements to not converged if there is at least one nonlocal element that did not converge
- need call to microstructure before first call to collect dotState for dependent states
- stiffness calculation (jacobian): if there are nonlocal elements, we also have to consider changes in our neighborhood's states; so for every perturbed component in a single ip, we have to loop over all elements; since this is extremely time-consuming, we just perturb one component per cycle, starting with the one that changes the most during regular time step.
- updateState gets a damping prefactor for our dotState that helps to improve convergence; prefactor is calculated according to change of dotState
IO:
- additional warning message for unknown crystal symmetry
(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
# IO has some additional functionality for Abaqus parsing
# ping pong scheme in FE interface now similar (and more human understandable) in both versions
# mesh has better splitting of different tasks, plus operation on database whenever possible
# FEsolver as new global var to indicate FEM solver type
# computation mode reshuffling: 6 is now Marc special case of recycling...
(state < relevant state) or (residuum < relative tolerance * state)
since the relevant value for the state variables depend on their nature and can vary by large scales (e.g. volume fraction: 1e-10, dislocation density: 1e5) it is not possible to set a unique value. instead the constitutive law has to decide what is relevant. therefore, all constitutive laws now read in parameters from the material.config that determine the values for relevantState [@luc: in dislobased law relevant State is for the moment generally set to 1e-200, so no additional parameters necessary in material.config. if you also want this feature, we can still implement it, no big deal]
- added sanity checks in constitutive_nonlocal.f90
- corrected coordinate transformation for backstress calculation in constitutive_nonlocal.f90
- corrected equations for evolution of dipole dislocation densities (athermal annihilation and formation by glide)
IO.f90 >>> adding "inRad" instead of using inRad from math.f90 module, since math.f90 module is now below IO.f90.
numerics.f90 >>> now can read the parameter "fixed_seed" from numerics.config. this parameter is used to set a pseudo-random number generator/fixed seeding. default value is 0 (zero), which will give fully random number.
math.f90 >> adding a possibility to fix the seeding (i.e., pseudo random number)
numerics.config >>> add a new parameter: "fixed_seed"
formerly, if the number of orientations requested was (far) less than the number of nonzero bins in the texture representation, you only got a subset of low phi1 values..! (that is the top corner in Euler space -- Hi Bing ;-) )
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