Commit Graph

27 Commits

Author SHA1 Message Date
Christoph Kords 366d52bd71 * former "relevantRho" and "relevantResistance" is renamed to "atol_rho" and "atol_resistance" and now used as an absolute tolerance for the state residuum. before it was used rather as significant state, so whenever the state dropped below that value it was considered converged. (In dislotwin and titanmod constitutive law there is only one value atol_rho which is used for all the states, though the state array consists not only of densities. We need further parameters here!)
* somewhat simplified convergence check for adaptive euler and runge-kutta
2010-10-26 13:16:37 +00:00
Christoph Kords fffe731447 * had to correct nonlocal slip system compatibility and flux calculation. last update gave wrong results. 2010-10-15 13:19:26 +00:00
Christoph Kords 724960686f * in nonlocal model: dislocation flux now with valid description also for large angle grain boundaries; transfer of dislocations from one slip system to the other according to new variable "constitutive_nonlocal_compatibility" which depends on the angle between slip plane normals and slip directions and is updated once per cycle in function "crystallite_orientations"
* reactivated debugging functionality for "non-standard" integration methods
2010-10-12 13:08:54 +00:00
Christoph Kords efd92d9b51 allocation of special state variables for "non-standard integration" was erroneous. used to produce segmentation fault for integration method 4 and 5. 2010-10-12 12:11:24 +00:00
Christoph Kords fce7590c17 * now able to choose method for state integration (integrator and integratorStiffness in numerics.config); standard is "Fixed Point Iteration", which is basically the same as before; others available are "Explicit Euler", "AdaptiveEuler", "Classical Runge-Kutta" and "Runge-Kutta Cash-Karp"
* 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
2010-10-01 12:18:49 +00:00
Alankar Alankar 7548858ffa Some useful changes in damper for quicker convergence. 2010-09-22 08:54:36 +00:00
Alankar Alankar 18c86ca0b1 Updated corresponding files for titanmod constitutive 2010-09-13 09:29:03 +00:00
Philip Eisenlohr 9a20f742ea leaner memory requirement to store states and their rates when calculating the crystallite stiffness 2010-09-13 09:13:25 +00:00
Christoph Kords 3ce1882d29 when calculating dislocation stress at grain boundaries, densities are now extrapolated similarly to like it was already done at free surfaces 2010-06-07 16:01:37 +00:00
Christoph Kords 0c5bc83469 in nonlocal_microstructure: at the model surface the excess density is now extrapolated from opposite neighbor instead of assuming zero density; this results in better modeling of the dislocation stress at the surface
restructured nonlocal_dotstate, to be able to easily switch on and off particular effects in the microstructure evolution
nonlocal_dotstate now enforces a cutback when single density runs the risk of becoming negative; in the case of a state already below the relevantState dotState is set to zero
introduced two new output variables: rho_dot_edge and rho_dot_screw
2010-05-21 08:51:15 +00:00
Denny Tjahjanto 9026cc4016 again corrections. but this version must work. 2010-03-24 16:23:21 +00:00
Denny Tjahjanto 40b1478dac the latest RGC model + corrections for "element homogeneous" feature 2010-03-24 13:20:12 +00:00
Philip Eisenlohr 8c8ed34356 reworked crystallite part to allow for flexible user output
--> 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.
2010-02-25 17:39:11 +00:00
Christoph Kords 97db70cf23 constitutive_nonlocal:
- 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
2010-02-17 13:21:36 +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
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
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
Luc Hantcherli bc5a408c1a Changed constitutive_dislobased into constitutive_dislotwin:
in constitutive.90
in constitutive_dislotwin.f90
in mpie_cpfem_marc.f90
2009-10-06 15:16:03 +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 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
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
Luc Hantcherli a16b8a619d Major update: corrected treatment of temperature 2009-07-01 10:29:35 +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