J2Plasticity.hGo to the documentation of this file.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: 1.5 $ 00017 // $Date: 2006/08/04 18:18:38 $ 00018 // $Source: /usr/local/cvs/OpenSees/SRC/material/nD/J2Plasticity.h,v $ 00019 00020 #ifndef J2Plasticity_h 00021 #define J2Plasticity_h 00022 00023 // Written: Ed "C++" Love 00024 // 00025 // J2 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 // set eta := 0 for rate independent case 00047 // 00048 00049 00050 #include <stdio.h> 00051 #include <stdlib.h> 00052 #include <math.h> 00053 00054 #include <Vector.h> 00055 #include <Matrix.h> 00056 #include <NDMaterial.h> 00057 00058 00059 class J2Plasticity : public NDMaterial { 00060 00061 //-------------------Declarations------------------------------- 00062 00063 public : 00064 00065 //null constructor 00066 J2Plasticity() ; 00067 00068 //full constructor 00069 J2Plasticity( int tag, 00070 int classTag, 00071 double K, 00072 double G, 00073 double yield0, 00074 double yield_infty, 00075 double d, 00076 double H, 00077 double viscosity = 0 ) ; 00078 00079 //elastic constructor 00080 J2Plasticity( int tag, int classTag, double K, double G ) ; 00081 00082 //destructor 00083 virtual ~J2Plasticity( ) ; 00084 00085 virtual const char *getClassType(void) const {return "J2Plasticity";}; 00086 00087 virtual NDMaterial* getCopy (const char *type); 00088 00089 //swap history variables 00090 virtual int commitState( ) ; 00091 00092 //revert to last saved state 00093 virtual int revertToLastCommit( ) ; 00094 00095 //revert to start 00096 virtual int revertToStart( ) ; 00097 00098 //sending and receiving 00099 virtual int sendSelf(int commitTag, Channel &theChannel) ; 00100 virtual int recvSelf(int commitTag, Channel &theChannel, 00101 FEM_ObjectBroker &theBroker ) ; 00102 00103 //print out material data 00104 void Print(OPS_Stream &s, int flag = 0) ; 00105 00106 virtual NDMaterial *getCopy (void) ; 00107 virtual const char *getType (void) const ; 00108 virtual int getOrder (void) const ; 00109 00110 protected : 00111 00112 //this is mike's problem 00113 static Tensor rank2; 00114 static Tensor rank4; 00115 00116 //material parameters 00117 double bulk ; //bulk modulus 00118 double shear ; //shear modulus 00119 double sigma_0 ; //initial yield stress 00120 double sigma_infty ; //final saturation yield stress 00121 double delta ; //exponential hardening parameter 00122 double Hard ; //linear hardening parameter 00123 double eta ; //viscosity 00124 00125 //internal variables 00126 Matrix epsilon_p_n ; // plastic strain time n 00127 Matrix epsilon_p_nplus1 ; // plastic strain time n+1 00128 double xi_n ; // xi time n 00129 double xi_nplus1 ; // xi time n+1 00130 00131 //material response 00132 Matrix stress ; //stress tensor 00133 double tangent[3][3][3][3] ; //material tangent 00134 static double initialTangent[3][3][3][3] ; //material tangent 00135 static double IIdev[3][3][3][3] ; //rank 4 deviatoric 00136 static double IbunI[3][3][3][3] ; //rank 4 I bun I 00137 00138 //material input 00139 Matrix strain ; //strain tensor 00140 00141 //parameters 00142 static const double one3 ; 00143 static const double two3 ; 00144 static const double four3 ; 00145 static const double root23 ; 00146 00147 //zero internal variables 00148 void zero( ) ; 00149 00150 //plasticity integration routine 00151 void plastic_integrator( ) ; 00152 00153 void doInitialTangent( ) ; 00154 00155 //hardening function 00156 double q( double xi ) ; 00157 00158 //hardening function derivative 00159 double qprime( double xi ) ; 00160 00161 //matrix index to tensor index mapping 00162 virtual void index_map( int matrix_index, int &i, int &j ) ; 00163 00164 00165 } ; //end of J2Plasticity declarations 00166 00167 #endif
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