Manual pages | Cast3M

$$$$ FOFI     NOTICE  CHAT      11/09/12    21:16:16     7124           
                                             DATE     11/09/12
                                             
    Operateur FOFI
    --------------                           Voir aussi : GRAD SIGM
                                                          CARA   BSIG   
   FORC1 = FOFISS  MODL1 SIG1 GRDEP1 ( CAR1 ) ;


   Description :
   -------------

   The FOFI operator calculates a field of nodal forces stemming
   from an integration of the product of a stress field by a
   displacement gradient field.
   

   Contents :
   ---------

   MODL1  : model object (MMODEL type)

   SIG1   : stress field (MCHAML type)

   GRDEP1 : displacement gradient field DEP1 (MCHAML type)

   CAR1   : characteristic field required for some elements
            (see note below) (MCHAML type, CARACTERISTIQUES
            subtype)

   FORC1  : field of nodal forces (type CHPOINT)




   Notes :
   ---------

   1 ) Given a stress field S and a displacement field U, the FOFI
       operator calculates the nodal force field so that the work 
       in the displacement field V equal :

                            /          k     k
                           |    ij   dU    dV
                           |   S   * --i * --j   dM
                           /M        dx    dx


       It is similar to BSIGMA as for the quadratic terms of the 
       strain tensor.

   2 ) In a Fourier analysis, the harmonic number used is that
       defined by the OPTION instruction.

   3 ) Characteristics must be specified when the geometrical description
       of the element cannot be done by means of the mesh, for instance,
       the thickness of plate elements or the inertias of beam elements.