Manual pages | Cast3M

$$$$ KTAN     NOTICE  CHAT      11/09/12    21:16:49     7124           
                                             DATE     11/09/12

    Operateur KTAN                           Voir aussi : KSIG RIGI
    --------------                                        COMP   

            -----------------------------------

            |   tangential stiffness matrix   |
            -----------------------------------


      RIG1 =  'KTAN' MODL1 SIG1 VAR1 MAT1
                           ( 'PREC' FLOT1 ) ( 'DT  ' FLOT2 )
                           ( 'SYME' )  ;


    Description :
    _____________

    The KTAN operator calculates the tangential stiffness matrix in
 elasto-plasticity. If ist not possible, this operator calculates 
the elastic stiffness matrix.


      Contents :
      __________

      MODL1 : model object (MMODEL type)

      SIG1  : stress field (MCHAML type, CONTRAINTES subtype)

      VAR1  : field of internal variables (MCHAML type, VARIABLES 
              INTERNES subtype)
              
      MAT1  : field of material and geometrical properties
              (MCHAML type, CARACTERISTIQUES subtype)

      'PREC': key word to indicate that the precison is the next
              argument
     
      FLOT1 : accuracy with which the user tries to know whether
              a state of stress is plastic or not (1.E-3 by default)

      'DT  ': key word to indicate that the time step is the next
              argument

      FLOT2 : time step for viscous models

      'SYME': keyword to indicate that only the symetrical part of the
              tangential matrix will be kept

      RIG1  : generated object (RIGIDITE type, RIGIDITE subtype)


            -----------------------------------
            |   tangential stiffness matrix   |
            |          by distrubance         |
            -----------------------------------


      RIG1 = 'KTAN' 'PERT' MOD1 CHE1 CHE2
                           ('C1' FLO1) ('C2' FLO2)
                           ('SYME') ;


    Description :
    _____________

   The KTAN operator calculates the tangential stiffness matrix by 
the disturbance method. From an intial state and a final state, this 
operator disturbs the strain increment, multiplying it by a given
coefficient, calculates the stresses associated with this disturbed
state and deduces the tangential stiffness matrix.


      Contents :
      __________

        MOD1  MMODEL   model object

        CHE1  MCHAML   set of fields describing the initial state
                       (see CHE2 in the instructions of 'COMP')

        CHE2  MCHAML   set of fields describing the final state
                       (see CHE3 in the instructions of 'COMP')
                       and must include the final stress field
        CAUTION ! if CHE2 contains several elementary zone associated
                  with the same elementary model, strains have to be 
                  in the first one.

        'C1'           keyword to indicate that C1 is the next argument

        FLO1  FLOTTANT strictly positive (1.D-3 by default)
                       multiplicative disturbance coefficient of the
                       strain increment

        'C2'           keyword to indicate that C2 is the next argument

        FLO2  FLOTTANT strictly positive (FLO1/100. by default)
                       minimal deformation disturbance

        'SYME'         keyword to indicate that only the symetrical part
                       of the tangential matrix will be kept

        RIG1  RIGIDITE generated object : stiffness matrix