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doc:user:integration:scheme:staggeredtm

Thermomechanical staggered integration scheme

Description

Old Metafor Version <= 2422

Used if MDE_NDYT=2. The mechanical scheme must be quasi-static (MDE_NDYN=0) or alpha genealized (MDE_NDYN=2). The thermal scheme is trapezoidal (MDE_THTY=1) or generalized midpoint (MDE_THTY=0). (see Global Parameters [REMOVED]).

For staggered schemes can be used (depending on MDE_NDYT):

  • MDE_NDYT = 2 : thermomechanical staged isothermal without reevaluation of stresses at the end of a step
  • MDE_NDYT = 3 : thermomechanical staged adiabatic without reevaluation of stresses at the end of a step
  • MDE_NDYT = 4 : thermomechanical staged isothermal with reevaluation of stresses at the end of a step
  • MDE_NDYT = 5 : thermomechanical staged adiabatic with reevaluation of stresses at the end of a step

New Metafor Version > 2422

tiMech = AlphaGeneralizedTimeIntegration(metafor)
tiTher = TrapezoidalThermalTimeIntegration(metafor)
tiTher.setTheta(_theta)
ti = StaggeredTmTimeIntegration(metafor)
ti.setIsAdiabatic(False)
ti.setWithStressReevaluation(False)
ti.setMechanicalTimeIntegration(tiMech)
ti.setThermalTimeIntegration(tiTher)
metafor.setTimeIntegration(ti)

The mechanical time integration scheme is either quasi static or alpha generalized family. The default _theta parameter value is 1.0 ([0,1]).

Be careful when using the adiabatic staged scheme with analytical stiffness matrix and variation of the mechanical parameters, convergence of the time steps may not be achieved.

Data set

To change a test case running with quasiStaticAlgorithm into a thermomechanical test :

  • Replace elements by their thermal version : Volume2DElement becomes TmVolume2DElement.
  • Replace materials by their thermal version : EvpIsoHHypoMaterial becomes TmEvpIsoHHypoMaterial.
  • Add new material dependency (optional) : matset[1].depend(P_HARD_1, fonction, Key(TO|RE)).
  • Add thermal parameters of material law (see materials).
  • Add initial temperature (optional) (metafor.getInitialConditionSet().define(no,type,TO|AB,val)).
  • Add temperature to contact matrices (optional) (see ElementProperties).
  • Add thermal boundary conditions:

Additional parameters

  • MDE_THTY :
    • = 0 generalized midpoint rule for the integration of transient thermal part (set MDR_THET).
    • = 1 generalized trapezoid rule for the integration of transient thermal part (set MDR_THET).
  • MDE_NDYT : must be equal to 2, 3, 4 or 5 to run the staged scheme.

(see Global Parameters [REMOVED])

doc/user/integration/scheme/staggeredtm.txt · Last modified: 2024/06/07 15:58 by vanhulle

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