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00001 /* ****************************************************************** **
00002 **    OpenSees - Open System for Earthquake Engineering Simulation    **
00003 **          Pacific Earthquake Engineering Research Center            **
00004 **                                                                    **
00005 **                                                                    **
00006 ** (C) Copyright 1999, The Regents of the University of California    **
00007 ** All Rights Reserved.                                               **
00008 **                                                                    **
00009 ** Commercial use of this program without express permission of the   **
00010 ** University of California, Berkeley, is strictly prohibited.  See   **
00011 ** file 'COPYRIGHT'  in main directory for information on usage and   **
00012 ** redistribution,  and for a DISCLAIMER OF ALL WARRANTIES.           **
00013 **                                                                    **
00014 ** ****************************************************************** */
00015                                                                         
00016 // $Revision: 1.2 $
00017 // $Date: 2001/01/23 08:46:28 $
00018 // $Source: /usr/local/cvs/OpenSees/SRC/material/nD/J2PlaneStress.h,v $
00019 
00020 #ifndef J2PlaneStress_h
00021 #define J2PlaneStress_h
00022 
00023 // Written: Ed "C++" Love
00024 //
00025 // J2PlaneStress isotropic hardening material class
00026 // 
00027 //  Elastic Model
00028 //  sigma = K*trace(epsilion_elastic) + (2*G)*dev(epsilon_elastic)
00029 //
00030 //  Yield Function
00031 //  phi(sigma,q) = || dev(sigma) ||  - sqrt(2/3)*q(xi) 
00032 //
00033 //  Saturation Isotropic Hardening with linear term
00034 //  q(xi) = simga_0 + (sigma_infty - sigma_0)*exp(-delta*xi) + H*xi 
00035 //
00036 //  Flow Rules
00037 //  \dot{epsilon_p} =  gamma * d_phi/d_sigma
00038 //  \dot{xi}        = -gamma * d_phi/d_q 
00039 //
00040 //  Linear Viscosity 
00041 //  gamma = phi / eta  ( if phi > 0 ) 
00042 //
00043 //  Backward Euler Integration Routine 
00044 //  Yield condition enforced at time n+1 
00045 //
00046 //  Send strains in following format :
00047 // 
00048 //     strain_vec = {   eps_00
00049 //                      eps_11
00050 //                    2 eps_01   }   <--- note the 2
00051 // 
00052 //  set eta := 0 for rate independent case
00053 //
00054 
00055 #include <iostream.h>
00056 #include <stdio.h> 
00057 #include <stdlib.h> 
00058 #include <math.h> 
00059 
00060 #include <Vector.h>
00061 #include <Matrix.h>
00062 
00063 #include <J2Plasticity.h>
00064 
00066 class J2PlaneStress : public J2Plasticity {
00067 
00069 
00070   public : 
00071 
00072   //null constructor
00073   J2PlaneStress( ) ;
00074 
00076   J2PlaneStress(   int    tag, 
00077                    double K,
00078                    double G,
00079                    double yield0,
00080                    double yield_infty,
00081                    double d,
00082                    double H,
00083                    double viscosity ) ;
00084 
00085 
00087   J2PlaneStress( int tag, double K, double G ) ;
00088 
00090   ~J2PlaneStress( ) ;
00091 
00093   NDMaterial* getCopy( ) ;
00094 
00096   const char* getType( ) const ;
00097 
00099   int getOrder( ) const ;
00100 
00102   int setTrialStrain( const Vector &strain_from_element) ;
00103 
00105   int setTrialStrain( const Vector &v, const Vector &r ) ;
00107   int setTrialStrainIncr( const Vector &v ) ;
00109   int setTrialStrainIncr( const Vector &v, const Vector &r ) ;
00110 
00112   const Vector& getStrain( ) ;
00113 
00115   const Vector& getStress( ) ;
00116 
00118   const Matrix& getTangent( ) ;
00119 
00121   int setTrialStrain(const Tensor &v) ;
00123   int setTrialStrain(const Tensor &v, const Tensor &r) ;    
00125   int setTrialStrainIncr(const Tensor &v) ;
00127   int setTrialStrainIncr(const Tensor &v, const Tensor &r) ;
00129   const Tensor& getTangentTensor( ) ;
00130 //jeremic@ucdavis.edu 22jan2001  const Tensor& getStressTensor( ) ;
00131 //jeremic@ucdavis.edu 22jan2001  const Tensor& getStrainTensor( ) ;  
00132 
00134   int sendSelf(int commitTag, Channel &theChannel) ;  
00136   int recvSelf(int commitTag, Channel &theChannel, 
00137                FEM_ObjectBroker &theBroker ) ;
00138   
00140   private : 
00141   
00142   //static vectors and matrices
00143   static Vector strain_vec ;     
00144   static Vector stress_vec ;     
00145   static Matrix tangent_matrix ; //material tangent in matrix notation
00146 
00147   //index mapping special for plane stress because of 
00149   void index_map( int matrix_index, int &i, int &j ) ;
00150 
00151 } ; //end of J2PlaneStress declarations
00152 
00153 
00154 #endif
00155 ÿ