J:/Tecgraf/prj/femoop/trunk/shp/shpquad6.h

// -------------------------------------------------------------------------
// ShpQuad6.h  -   this file contains  methods  for the 6-noded
//                 quadrilateral  element shape.
// -------------------------------------------------------------------------
// Remarks:
// -------------------------------------------------------------------------
// This shape contains two extra points for  displacement  interpolation.
// The extra  shape  functions  [ (1-r*r) and (1-s*s) ]  are
// associated  to  these  points ( "nodeless" points ) in
// order to compute the element stiffness  matrix.  After
// that, the stiffness matrix is condensed  to obtain the
// final element stiffness matrix in terms of the original
// corner  nodes ( as in a Q4 element ). This element  is
// "non-conforming" because the shape mode (1-r*r) can be
// activated  in a  given element and not be activated in
// an adjacent finite element as shown in figure below:
// -------------------------------------------------------------------------
// The numbering scheme is:
//
//                    s
//                    ^
//                    |    (natural coord. system)
//                    |
//                    -----> r
//
//                        4 +---------------+ 3
//                          |               |
//                          |               |
//                          |               |
//                          |       * 5,6   |
//                          |               |
//                          |               |
//                          |     QUAD6     |
//                        1 +---------------+ 2
//
// Obs: 5,6 are internal dofs (nodeless).
// -------------------------------------------------------------------------
//
// $Author: evandro $
// $Revision: 1.3 $
// $Date: 1999/04/12 14:58:25 $
// $State: Exp $
//
// -------------------------------------------------------------------------

#ifndef _SHPQUAD6_H
#define _SHPQUAD6_H

#include "gbldefs.h"
#include "shpplane.h"

// -------------------------------------------------------------------------
// Quad6B (Finite) Element Shape class:
//
class cShapeQuad6 : public cPlaneShape
{
 public:
                cShapeQuad6       ( void );
  virtual      ~cShapeQuad6       ( void );
          int   GetMapOrder       ( void ) { return 1; }
          void  MapFunc           ( sNatCoord *, double * );
          void  ShapeFunc         ( sNatCoord *, double * );
          void  DerivMapRST       ( sNatCoord *, sDerivNat * );
          void  DerivShpRST       ( sNatCoord *, sDerivNat * );
          int   GetEdge           ( int *, eShapeType *, int *, int * );
          int   GetFace           ( int *, eShapeType *, int *, int * );
          void  GetNatCoordMapNode( sNatCoord * );
};

#endif

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