ManzariDafaliasYieldSurface.h

// -*-c++-*-
//----------------------------------------------------------------------------
//  XC program; finite element analysis code
//  for structural analysis and design.
//
//  Copyright (C)  Luis C. Pérez Tato
//
//  This program derives from OpenSees <http://opensees.berkeley.edu>
//  developed by the  «Pacific earthquake engineering research center».
//
//  Except for the restrictions that may arise from the copyright
//  of the original program (see copyright_opensees.txt)
//  XC is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or 
//  (at your option) any later version.
//
//  This software is distributed in the hope that it will be useful, but 
//  WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details. 
//
//
// You should have received a copy of the GNU General Public License 
// along with this program.
// If not, see <http://www.gnu.org/licenses/>.
//----------------------------------------------------------------------------
//================================================================================
//# COPYRIGHT (C):     :-))                                                   #
//# PROJECT:           Object Oriented Finite Element Program                 #
//# PURPOSE:           Manzari - Dafalias  yield criterion                     #
//# CLASS:             ManzariDafaliasYieldSurface                                         #
//#                                                                           #
//# VERSION:                                                                  #
//# LANGUAGE:          C++.ver >= 2.0 ( Borland C++ ver=3.00, SUN C++ ver=2.1 )  #
//# TARGET OS:         DOS || UNIX || . . .                                   #
//# PROGRAMMER(S):     Boris Jeremic, ZHaohui Yang                            #
//#                                                                           #
//#                                                                           #
//# DATE:              August 03 '93                                          #
//# UPDATE HISTORY:    August 08 '00                                          #
//#                                                                           #
//#                                                                           #
//#                                                                           #
//#                                                                           #
//# SHORT EXPLANATION:                                                        #
//#                                                                           #
//#                                                                           #
//=============================================================================
//*/

#ifndef ManzariDafaliasYieldSurface_H
#define ManzariDafaliasYieldSurface_H

#include "material/nD/template_3d_ep/YieldSurface.h"

namespace XC {
class ManzariDafaliasYieldSurface: public YieldSurface
  {
  public:
    ManzariDafaliasYieldSurface(void); // Default constructor
    YieldSurface *getCopy(void) const; // create a clone of itself

    double f(const EPState *EPS) const;
    BJtensor dFods(const EPState *EPS) const;

    // Redefine 1st derivative of F over scalar internal variables
    double xi_s1( const EPState *EPS ) const;  // df/dm
    //double xi_s2( const EPState *EPS ) const;

    // Redefine 1st derivative of F over tensorial internal variables
    BJtensor xi_t1(const EPState *EPS) const; // dF / d alpha_ij

    virtual void print(std::ostream &os) const;  
  };
 
} // end of XC namespace

#endif