Commit Graph

65 Commits

Author SHA1 Message Date
Christoph Kords a2037db9c6 corrected sign of screw part of dislocation stress 2010-02-12 12:54:00 +00:00
Christoph Kords ed8446e0f3 - corrected contribution of immobile singles to dipole formation and annihilation rates
- remobilization of immobile singles immediately increases the mobile single dislocation density and therefore directly affects all other mechanisms in dotState
2010-01-06 09:54:00 +00:00
Christoph Kords dce840c0a5 - introduction of immobile (used) single dislocation densities as new state variables
- changed nomenclature (rho -> rhoSgl) to distinguish precisely between single dislocation density and total dislocation density
- changed material.config accordingly
2010-01-05 16:07:24 +00:00
Christoph Kords 1f7aebfa4d new subroutine crystallite_orientations: calculates the orientation matrix and the euler angles and - in case of single grain ips - the misorientation for each neighboring ip.
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.
2009-12-18 15:46:33 +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
Luc Hantcherli 67f87486b1 in constitutive_dislotwin.f90:
in constitutive_nonlocal.f90:

Derivatives of shear rates w.r.t. resolved shear stress HAVE to be positive.
Computation of dgdot_dtauslip is now correct.
2009-11-06 17:46:12 +00:00
Christoph Kords 9892fd9a10 sorry: initialization of periodicBC was erroneous 2009-10-20 16:38:05 +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
Christoph Kords 9b3a59646a constitutive_nonlocal
- take orientation gradients into account when calculating dislocation stress and dislocation fluxes
- hard coded value for nu
- changed kinetics (parameter G0 is currently defined as a parameter, needs to be read from material.config)
- added some output statements

constitutive: 
- some functions and subroutines needed additional input variables for passing to constitutive_nonlocal 

crystallite:
- some functions and subroutines needed additional input variables for passing to constitutive
- call microstructure with current temperature, Fp, Fe, not "sub0" values
- show number of IPs, that are "onTrack" instead of those not "onTrack"
- calculate Fe at beginning of substep, since we need it for state preguess
2009-10-07 15:31:52 +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
Christoph Kords f27d66a9ae constitutive_nonlocal:
- dipole dislocations with evolution

crystallite.f90:
- collect state uses subdt and subTstar0_v
- in nonlocal modus: set all crystallites to broken if one is not on track anymore after either stress integration or state update
- constitutive_microstructure is now called inside state update and not in integrate_stress anymore

material.config:
- new parameter for nonlocal constitution

CPFEM.f90:
- age Tstar after increment was finished
2009-08-28 13:50:47 +00:00
Christoph Kords 1dbd0865db constitutive_nonlocal.f90
- 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
2009-08-24 08:16:01 +00:00
Christoph Kords 2aae7b7574 added dislocation multiplication to dotState in constitutive_nonlocal.f90
cleaned up debugging output statements to *.out file
2009-08-12 11:22:02 +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