cl_JcFunction_ModifiedKim.hpp

Go to the documentation of this file.

/*
 * BELFEM -- The Berkeley Lab Finite Element Framework
 * Copyright (c) 2026, The Regents of the University of California,
 * through Lawrence Berkeley National Laboratory (subject to receipt of any required
 * approvals from the U.S. Dept. of Energy).  All rights reserved.
 *
 * Developers: Christian Messe, Gregory Giard
 *
 * See the top-level LICENSE file for the complete license and disclaimer.
 */
 
#ifndef BELFEM_CL_JCFUNCTIONMODIFIEDKIM_HPP
#define BELFEM_CL_JCFUNCTIONMODIFIEDKIM_HPP
 
#include "cl_JcFunction.hpp"
 
namespace belfem
{
    namespace material
    {
//------------------------------------------------------------------------------

        class JcFunctionModifiedKim : public JcFunction
        {
            const real mJc0 ;    
            const real mB0 ;     
            const real mK2 ;     
            const real mAlpha ;  
 
        public:

            JcFunctionModifiedKim(
                const real jc0,
                const real B0,
                const real k2,
                const real alpha ) :
            mJc0( jc0 ), mB0( B0 ), mK2( k2 ), mAlpha( alpha )
            {
                this->set_dependency( JcParameter::normB );
                this->set_dependency( JcParameter::angleNxB );
            }
 
            ~JcFunctionModifiedKim() override = default;

            real
            eval( const real normB, const real angle  ) const override
            {
                real c = std::cos( angle );
                real c2 = c * c;
                real s2 = 1.0 - c2;
 
                return mJc0 /
                    std::pow( 1. +
                        std::sqrt( ( mK2 * s2 + c2 ) ) * normB / mB0, mAlpha );
 
            }

            real
            deval_dB( const real normB, const real angle, const real T ) const override
            {
                real c = std::cos( angle );
                real c2 = c * c;
                real s2 = 1.0 - c2;
                real s = std::sqrt( mK2 * s2 + c2 );
                real jc = mJc0 / std::pow( 1. + s * normB / mB0, mAlpha );
 
                return -mAlpha * jc * s / ( mB0 + s * normB );
            }
        };
    }
}
#endif //BELFEM_CL_JCFUNCTIONMODIFIEDKIM_HPP