Manual pages | Cast3M

$$$$ PRES     NOTICE  CHAT      11/09/12    21:17:43     7124           
                                             DATE     11/09/12
                                             
  Operateur PRES                           Voir aussi :
    --------------   
  CHPO1 = PRES | 'MASS' MODL1  | FLOT1 GEO1 | ;
               |               | CHPO2      |
               |
               | 'COQU' MODL1  | FLOT1      | |  'NORM'        | (CAR1);
               |               | CHPO2      | |   VEC1         |
               |                              |  'POIN'  POIN1 |
               |
               | 'FISS' MODL1  | FLOT1      |  VEC1 POIN1 CAR1 ;
               |               | CHPO2      |
               |
               | 'TUYA' MODL1  CAR1 ;
               |
               | 'SHB8' MODL1  | FLOT1       |  'INTERNE'  | |  ;
               |               |             |  'EXTERNE'  | | 
               |               |                             |     
               |               | CHPO2                       |    
 


    Description :
    _____________

    The PRES operator calculates the nodal forces which are 
 equivalent to a pressure applied on an object.



      Contents :
      __________


      MASS |
      COQU | : key word referring to the type of element on which 
      FISS |   the pressure is applied (solid, shell, linesprings,
      TUYA |   pipe elements or SHB8 shell element)
      SHB8 |

      MODL1  : object on which the pressure is applied (MMODEL type)

      FLOT1  : pressure algebraic value (FLOTTANT type)

      GEO1   : for the solid elements, mesh on which the pressure
               is applied (MAILLAGE type)

      CHPO2  : field containing the pressure values at the nodes
               (CHPOINT type)

      NORM   : key word indicating that the pressure is positive
               when it is carried by the positive normal to the
               element

      VEC1   : vector providing the direction according to which the
               pressure is applied (POINT type). (Works only in 3D)

      POIN   : key word followed by  :
      POIN1  : point to which the pressure is applied (POINT type)
               Used only for shells and linesprings. (Works only
               in 3D)

      CAR1   : characteristics of shells, linesprings or pipes
               (MCHAML type, CARACTERISTIQUES subtype) :
               - for the thick shells, contains the values of the
               thicknesses at the points of integration
               - for the linesprings, contains the values of the
               characteristics at the points of integration
               - for the pipes, contains the value of the internal
               pressure
               
      'INTERNAL' :The pressure acts on the internal (external) surface.      
      'EXTERNAL'  (the mesh defined within MODL1 must contain
                  references to outside surfaces see operator ORIE)   
               

      CHPO1  : equivalent nodal forces (CHPOINT type)


    Note :
    ________

      WARNING : If the used MODELE is larger than the area where the
pressure is defined (by CHPO2) then boundary elemnts will support also 
a pressure. We advise you to give to the operator a reduction of the
MODELE to the concerned elements.

      For the shells, the surface elements on which the pressure 
 is applied are reoriented.

      The angle stemming from the vector and the face of an element
 must be greater than 1 degree.

      For the solid elements, it is considered that the pressure
 is directed towards the solid inside. In case of a depression, it
 is required that a pressure or a field by negative pressure points
 be supplied.

      With the NORM option, the normal M to the element is defined
 so that the result with the shell element of numbering (i,j) be
 (ij,N)=+90.

      FOR SHB8 elements a positive presure is oriented through the 
      element if it is well oriented ( see operator ORIE).