Commit Graph

19 Commits

Author SHA1 Message Date
Denny Tjahjanto 3ab5cdc770 Additional feature to the RGC scheme: The volumetric consistency constraint. This is implemented by penalizing any volumetric discrepancy which occurs due to severe relaxation. The penalty for volume inconsistency is described using a power-law model. The setting for this function can be done in the numerics.config via three new parameters, i.e., maxvoldiscrepancy_RGC, voldiscrepancymod_RGC and discrepancypower_RGC. For monintoring, an extra output variable in prescribed in the material.config in the RGC section, namely "(output) volumediscrepancy".
IO.f90 and numerics.f90 has been modified accordingly to accommodate these changes
2009-12-16 16:20:53 +00:00
Franz Roters 39d1932e2b corrected line parsing now counts all parts 2009-12-15 16:03:53 +00:00
Christoph Kords d784153e0c constitutive_nonlocal:
- 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
2009-12-15 08:20:31 +00:00
Denny Tjahjanto 6702cb3baa Introduction of a numerical viscosity into the RGC scheme to improve the convergent behavior and the numerical stability of the scheme (see: homogenization_RGC.f90). These changes have been incorporated in all related subroutines (homogenization.f90, IO.f90, numerics.config and numerics.f90). 2009-11-17 13:42:38 +00:00
Denny Tjahjanto cb88019aa6 introduced a flexibility in cut-backing scheme in homogenization.f90 and in crystallite.f90:
(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
2009-11-10 13:36:27 +00:00
Christoph Kords c1ee34d235 constitutive_nonlocal:
- 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
2009-10-20 14:36:03 +00:00
Philip Eisenlohr 974116808b fixed a potential memory leak for hexagonal structures. added some status output to constitutive_xx 2009-10-15 20:02:52 +00:00
Philip Eisenlohr c3cb72d356 put some comments to hybridIA 2009-10-14 13:21:03 +00:00
Philip Eisenlohr 21cad32137 # new interface for Abaqus
# 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...
2009-10-12 16:01:49 +00:00
Christoph Kords b09b2b17f3 convergence of state in crystallite is now tested as follows:
(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)
2009-09-18 15:37:14 +00:00
Franz Roters 2029b23f98 added version information to all files
do NOT edit text like this:
$Id: constitutive_phenopowerlaw.f90 406 2009-08-31 14:13:10Z MPIE\f.roters $
2009-08-31 15:09:15 +00:00
Franz Roters bb0840ecb2 constitutive_phenopowerlaw.f90: check for non-zero w0_slip
IO.f90: added respecteive error message

constitutive_phenopowerlaw.f90: first test with automatic file Id
2009-08-31 14:13:10 +00:00
Denny Tjahjanto 644265381e mpie_cpfem_marc.f90 >>> changing the compilation sequence of modules: numerics.f90 and IO.f90 move up, while math.f90 down.
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"
2009-08-27 15:30:40 +00:00
Denny Tjahjanto cafc39b183 replaces Nast with Nreps in hybridIA
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 ;-) )
2009-08-13 13:21:22 +00:00
Christoph Kords 8ed3ddc03b now with first draft of nonlocal constitutive law
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
2009-08-11 16:31:57 +00:00
Denny Tjahjanto 360fb069ba List of changes/modifications:
* IO.f90 :: Adding error messages for RGC homogenization
* crystallite.f90 :: Modifying convergent criteria in crystalline_updateState and crystalline_updateTemperature
* material.f90 :: Adding IO_lc in homogenization_type(Name)
* debug.f90 :: Adding debbugging statement and counter for material point loop
* homogenization.f90 :: Adding homogenization_RGC blocks
* homogenization_isostrain.f90 :: Modifying argument of homogenization_isostrain_stateInit
* mpie_cpfem_marc.f90 :: Adding homogenization_RGC include
* numerics.f90 :: Adding numerical parameters for RGC scheme
* math.f90 :: Changing function name: math_permut to math_civita
2009-07-31 12:02:20 +00:00
Philip Eisenlohr f337847f35 quite some changes:
# 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
2009-07-22 16:07:19 +00:00
Christoph Kords fe2f3e4d36 - added sanity check for temperature tolerance
- added temperature tolerance in numerics.config
2009-07-02 16:37:48 +00:00
Franz Roters a6ccfe2e44 restructured the repository: renamed trunk into code, moved documentation one directory up, therefore you can now checkout either code or documentation only if you like 2009-06-25 07:17:59 +00:00