J:/Tecgraf/prj/femoop/trunk/elc/elcdsh.h

// -------------------------------------------------------------------------
// ElcDSh.h - This header file contains data structure for generic
//            ( free form ) degenerated shell finite element classes.
//            It is called degenerated because its shape can be
//            obtained by degeneration of a solid element.
// -------------------------------------------------------------------------
// Description:
//            This file contains the data structure to the degenerated shell
//            finite element superclass. 
//              
// -------------------------------------------------------------------------
// Remarks:
//            This formulation assumes that the shell mid-surface
//            "normals" (not strictly perpendicular to the surface)
//            remain straight after deformation. It assumes that 
//            geometry and displacements are interpolated using the
//            same shape functions. The nodal "normal" vectors are 
//            assumed to be given. If not, the program is aborted. 
//             
//-------------------------------------------------------------------------
//
// $Author: evandro $
// $Revision: 1.2 $
// $Date: 1999/04/12 14:48:47 $
// $State: Exp $
//
// -------------------------------------------------------------------------

#ifndef _ELCDSH_H 
#define _ELCDSH_H 

#include "gbldefs.h"
#include "element.h"
#include "shape.h"

// -------------------------------------------------------------------------
// Definition of a Degenerated Shell Element Class:
//
class cElcDegShell : public cElement
{
 protected:
         sVector     *_sV1,           // Nodal Vector
                     *_sV2,           // Nodal Vector
                     *_sV3;           // Nodal Vector
         double      *_dNodThick;     // nodal thicknesses
         int          _ConstantThickness;
                                      // constant thickness flag
 public:

                    cElcDegShell      ( eShapeType );
  virtual          ~cElcDegShell      ( void );
           void     SetNodalValues    ( void );
  virtual  double   GetVol            ( void ) { return 0.0; }
  virtual  double   GetArea           ( void ) { return 0.0; }
  virtual  void     Stiffness         ( double * ) { }
  virtual  void     CalcIntPtStress   ( void )  { }
  virtual  void     CalcIntPtStress   ( cIntPt *, sTensor * )  { }
           void     NodeStress        ( sTensor * );
  virtual  int      InternalForce     ( double * ) { return 1; }
  virtual  void     NormTensor        ( sTensor *, double * ) { };
  virtual  void     NormTensor        ( sTensor *, cIntPt *, double * ){ }
  virtual  void     NormTensor        ( sTensor *, cIntPt *, double *,
                                        double * ){ }
           void     TMatrix           ( sVector [3], double ** );
           void     BaMatrix          ( double **, double *,
                                        sDerivNat *, double **);
           void     BbMatrix          ( double **, sDerivNat *,
                                        double **);
           void     TRMatrix          ( void );

};

#endif

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