Manual pages | Cast3M

$$$$ CH_THETX NOTICE  CHAT      11/09/12    21:15:26     7124           
                                             DATE     11/09/12

    Procedure CH_THETX                       Voir aussi : G_THETA
    ------------------   
    THETA TABUTIL = CH_THETX SUPTAB ;

                          SUPTAB . 'MAILLAGE' 
                                 . 'PSI'
                                 . 'PHI'
                                 . 'FRONT_FISSURE' 
                                 . 'COUCHE' 


    Description:
    ____________

    Called by the G_THETA procedure for calculating the energy 
    release rate G or the C integral by the G_THETA method, 
    the present procedure defines a chpoint field for XFEM elements.
    The norm of this field is 1 inside a crown surrounding the crack tip
    and 0 outside. The direction of the vector gives the direction of 
    the virtual crack propagation.
    
    Not available for 3D crack problems by now.
    

    Input data
    ----------

    SUPTAB = Object (TABLE type) used for defining the options and 
             the calculation. The indices of the SUPTAB object
             are words (to be written in words). Here is their list :

 
    COMPULSORY FOR ALL CASES
    °°°°°°°°°°°°°°°°°°°°°°°°

    SUPTAB.'MAILLAGE' = It is the structure whole mesh
                        (mesh used in the finite
                        elements analysis)
                        
    SUPTAB.'PSI'  = CHPOINT object representing the 1st level set
                    function which describes the crack
    SUPTAB.'PHI'  = CHPOINT object representing the 2nd level set
                    function which describes the crack
                    
    SUPTAB.'FRONT_FISSURE' = This is the crack front 
                            -POINT (crack tip) in 2D
                            -MAILLAGE (front line) in 3D
                             
    SUPTAB.'COUCHE'   = It is the number of layers of elements 
                        surrounding the crack front that support the 
                        virtual crack extension.


    OUPUT
    °°°°°

    THETA = Objet of type :                                              
                                                                        
         - TABLE for a 3D crack front, it is a 
                 table indexed by the points of
                 the front containing the CHPOINT 
                 containing the THETA field.
         - CHPOINT for a 2D crack front (3D for thin 
                 shell element), containing the THETA 
                 field.

     TABUTIL = Objet of type TABLE containing the vector
               giving the direction of the THETA field