beam_flutter_sensitivity.cpp

Go to the documentation of this file.

/*
 * MAST: Multidisciplinary-design Adaptation and Sensitivity Toolkit
 * Copyright (C) 2013-2020  Manav Bhatia and MAST authors
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */


// BOOST includes
#include <boost/test/unit_test.hpp>


// MAST includes
#include "examples/fsi/beam_flutter_solution/beam_euler_fsi_flutter_solution.h"
#include "tests/base/test_comparisons.h"
#include "elasticity/structural_system_initialization.h"
#include "elasticity/structural_discipline.h"
#include "property_cards/solid_1d_section_element_property_card.h"
#include "base/parameter.h"
#include "base/constant_field_function.h"
#include "property_cards/isotropic_material_property_card.h"
#include "elasticity/structural_element_base.h"
#include "base/nonlinear_system.h"


BOOST_FIXTURE_TEST_SUITE  (BeamFSISmallDisturbanceEulerFlutterAnalysis,
                           MAST::BeamEulerFSIFlutterAnalysis)



BOOST_AUTO_TEST_CASE    (BeamFSISmallDisturbanceEulerFlutterSensitivityAnalysis) {
    
    const Real
    delta    = 1.e-5,
    tol      = 1.e-3;
    
    Real
    V0       = 0.,
    dV       = 0.,
    dV_fd    = 0.;
    
    
    std::vector<Real>
    eig_vec,
    deig_vec;
    
    V0       = this->solve(false);
    
    // now iterate over all the parameters and calculate the analytical
    // sensitivity and compare with the numerical sensitivity
    
    Real
    p0    = 0.,
    dp    = 0.;
    
    // now evaluate the direct sensitivity
    
    for (unsigned int i=0; i<this->_params_for_sensitivity.size(); i++ ) {
        
        MAST::Parameter& f = *this->_params_for_sensitivity[i];
        
        // calculate the analytical sensitivity
        // analysis is required at the baseline before sensitivity solution
        // and the solution has changed after the previous perturbed solution
        this->solve(false, 1.e-4, 100);
        dV = this->sensitivity_solve(f);
        
        // now calculate the finite difference sensitivity
        
        // identify the perturbation in the parameter
        p0           = f();
        (fabs(p0) > 0)?  dp=delta*p0 : dp=delta;
        f()         += dp;
        
        // solve at the perturbed parameter value
        dV_fd        = this->solve(false);
        
        dV_fd       -= V0;
        dV_fd       /= dp;
        
        // reset the parameter value
        f()        = p0;
        
        // now compare the eigenvalue sensitivity
        BOOST_TEST_MESSAGE("  ** dV_F/dp (total) wrt : " << f.name() << " **");
        BOOST_CHECK(MAST::compare_value( dV_fd,  dV, tol));
    }
}

BOOST_AUTO_TEST_SUITE_END()