C++ AssemblyContext::get_elem_solution方法代码示例

  void ParsedInteriorQoI::element_qoi_derivative( AssemblyContext& context,
                                                  const unsigned int qoi_index )
  {
    libMesh::FEBase* element_fe;
    context.get_element_fe<libMesh::Real>(0, element_fe);
    const std::vector<libMesh::Real> &JxW = element_fe->get_JxW();

    const std::vector<libMesh::Point>& x_qp = element_fe->get_xyz();

    // Local DOF count and quadrature point count
    const unsigned int n_u_dofs = context.get_dof_indices().size();

    unsigned int n_qpoints = context.get_element_qrule().n_points();

    // Local solution vector - non-const version for finite
    // differenting purposes
    libMesh::DenseVector<libMesh::Number>& elem_solution =
      const_cast<libMesh::DenseVector<libMesh::Number>&>
        (context.get_elem_solution());

    /*! \todo Need to generalize this to the multiple QoI case */
    libMesh::DenseVector<libMesh::Number> &Qu =
      context.get_qoi_derivatives()[qoi_index];

    for( unsigned int qp = 0; qp != n_qpoints; qp++ )
      {
        // Central finite differencing to approximate derivatives.
        // FIXME - we should hook the FParserAD stuff into
        // ParsedFEMFunction

        for( unsigned int i = 0; i != n_u_dofs; ++i )
          {
            libMesh::Number &current_solution = elem_solution(i);
            const libMesh::Number original_solution = current_solution;

            current_solution = original_solution + libMesh::TOLERANCE;

            const libMesh::Number plus_val =
              (*qoi_functional)(context, x_qp[qp], context.get_time());

            current_solution = original_solution - libMesh::TOLERANCE;

            const libMesh::Number minus_val =
              (*qoi_functional)(context, x_qp[qp], context.get_time());

            Qu(i) += (plus_val - minus_val) *
                     (0.5 / libMesh::TOLERANCE) * JxW[qp];

            // Don't forget to restore the correct solution...
            current_solution = original_solution;
          }
      }
  }

  void ScalarODE::nonlocal_constraint(bool compute_jacobian,
				      AssemblyContext& context,
				      CachedValues& /* cache */ )
  {
    libMesh::DenseSubMatrix<libMesh::Number> &Kss =
            context.get_elem_jacobian(_scalar_ode_var, _scalar_ode_var); // R_{s},{s}

    libMesh::DenseSubVector<libMesh::Number> &Fs =
            context.get_elem_residual(_scalar_ode_var); // R_{s}

    const libMesh::Number constraint =
      (*constraint_function)(context, libMesh::Point(0),
                             context.get_time());

    Fs(0) += constraint;

    if (compute_jacobian)
      {
        // FIXME: we should replace this hacky FDM with a hook to the
        // AD fparser stuff
        libMesh::DenseSubVector<libMesh::Number> &Us =
          const_cast<libMesh::DenseSubVector<libMesh::Number>&>
            (context.get_elem_solution(_scalar_ode_var)); // U_{s}

        const libMesh::Number s = Us(0);
        Us(0) = s + this->_epsilon;
        libMesh::Number constraint_jacobian =
          (*constraint_function)(context, libMesh::Point(0),
                                 context.get_time());

        Us(0) = s - this->_epsilon;
        constraint_jacobian -=
          (*constraint_function)(context, libMesh::Point(0),
                                 context.get_time());
           
        Us(0) = s;
        constraint_jacobian /= (2*this->_epsilon);

        Kss(0,0) += constraint_jacobian *
          context.get_elem_solution_derivative();
      }

    return;
  }

  void ElasticCableRayleighDamping<StressStrainLaw>::damping_residual( bool compute_jacobian,
                                                                       AssemblyContext& context,
                                                                       CachedValues& /*cache*/)
  {
    // First, do the "mass" contribution
    this->mass_residual_impl(compute_jacobian,
                               context,
                               &libMesh::FEMContext::interior_rate,
                               &libMesh::DiffContext::get_elem_solution_rate_derivative,
                               _mu_factor);

    // Now do the stiffness contribution
    const unsigned int n_u_dofs = context.get_dof_indices(this->_disp_vars.u()).size();

    const std::vector<libMesh::Real> &JxW =
      this->get_fe(context)->get_JxW();

    // Residuals that we're populating
    libMesh::DenseSubVector<libMesh::Number> &Fu = context.get_elem_residual(this->_disp_vars.u());
    libMesh::DenseSubVector<libMesh::Number> &Fv = context.get_elem_residual(this->_disp_vars.v());
    libMesh::DenseSubVector<libMesh::Number> &Fw = context.get_elem_residual(this->_disp_vars.w());

    //Grab the Jacobian matrix as submatrices
    //libMesh::DenseMatrix<libMesh::Number> &K = context.get_elem_jacobian();
    libMesh::DenseSubMatrix<libMesh::Number> &Kuu = context.get_elem_jacobian(this->_disp_vars.u(),this->_disp_vars.u());
    libMesh::DenseSubMatrix<libMesh::Number> &Kuv = context.get_elem_jacobian(this->_disp_vars.u(),this->_disp_vars.v());
    libMesh::DenseSubMatrix<libMesh::Number> &Kuw = context.get_elem_jacobian(this->_disp_vars.u(),this->_disp_vars.w());
    libMesh::DenseSubMatrix<libMesh::Number> &Kvu = context.get_elem_jacobian(this->_disp_vars.v(),this->_disp_vars.u());
    libMesh::DenseSubMatrix<libMesh::Number> &Kvv = context.get_elem_jacobian(this->_disp_vars.v(),this->_disp_vars.v());
    libMesh::DenseSubMatrix<libMesh::Number> &Kvw = context.get_elem_jacobian(this->_disp_vars.v(),this->_disp_vars.w());
    libMesh::DenseSubMatrix<libMesh::Number> &Kwu = context.get_elem_jacobian(this->_disp_vars.w(),this->_disp_vars.u());
    libMesh::DenseSubMatrix<libMesh::Number> &Kwv = context.get_elem_jacobian(this->_disp_vars.w(),this->_disp_vars.v());
    libMesh::DenseSubMatrix<libMesh::Number> &Kww = context.get_elem_jacobian(this->_disp_vars.w(),this->_disp_vars.w());

    unsigned int n_qpoints = context.get_element_qrule().n_points();

    // All shape function gradients are w.r.t. master element coordinates
    const std::vector<std::vector<libMesh::Real> >& dphi_dxi = this->get_fe(context)->get_dphidxi();

    const libMesh::DenseSubVector<libMesh::Number>& u_coeffs = context.get_elem_solution( this->_disp_vars.u() );
    const libMesh::DenseSubVector<libMesh::Number>& v_coeffs = context.get_elem_solution( this->_disp_vars.v() );
    const libMesh::DenseSubVector<libMesh::Number>& w_coeffs = context.get_elem_solution( this->_disp_vars.w() );

    const libMesh::DenseSubVector<libMesh::Number>& dudt_coeffs = context.get_elem_solution_rate( this->_disp_vars.u() );
    const libMesh::DenseSubVector<libMesh::Number>& dvdt_coeffs = context.get_elem_solution_rate( this->_disp_vars.v() );
    const libMesh::DenseSubVector<libMesh::Number>& dwdt_coeffs = context.get_elem_solution_rate( this->_disp_vars.w() );

    // Need these to build up the covariant and contravariant metric tensors
    const std::vector<libMesh::RealGradient>& dxdxi  = this->get_fe(context)->get_dxyzdxi();

    const unsigned int dim = 1; // The cable dimension is always 1 for this physics

    for (unsigned int qp=0; qp != n_qpoints; qp++)
      {
        // Gradients are w.r.t. master element coordinates
        libMesh::Gradient grad_u, grad_v, grad_w;
        libMesh::Gradient dgradu_dt, dgradv_dt, dgradw_dt;

        for( unsigned int d = 0; d < n_u_dofs; d++ )
          {
            libMesh::RealGradient u_gradphi( dphi_dxi[d][qp] );
            grad_u += u_coeffs(d)*u_gradphi;
            grad_v += v_coeffs(d)*u_gradphi;
            grad_w += w_coeffs(d)*u_gradphi;

            dgradu_dt += dudt_coeffs(d)*u_gradphi;
            dgradv_dt += dvdt_coeffs(d)*u_gradphi;
            dgradw_dt += dwdt_coeffs(d)*u_gradphi;
          }

        libMesh::RealGradient grad_x( dxdxi[qp](0) );
        libMesh::RealGradient grad_y( dxdxi[qp](1) );
        libMesh::RealGradient grad_z( dxdxi[qp](2) );

        libMesh::TensorValue<libMesh::Real> a_cov, a_contra, A_cov, A_contra;
        libMesh::Real lambda_sq = 0;

        this->compute_metric_tensors( qp, *(this->get_fe(context)), context,
                                      grad_u, grad_v, grad_w,
                                      a_cov, a_contra, A_cov, A_contra,
                                      lambda_sq );

        // Compute stress tensor
        libMesh::TensorValue<libMesh::Real> tau;
        ElasticityTensor C;
        this->_stress_strain_law.compute_stress_and_elasticity(dim,a_contra,a_cov,A_contra,A_cov,tau,C);

        libMesh::Real jac = JxW[qp];

        for (unsigned int i=0; i != n_u_dofs; i++)
          {
            libMesh::RealGradient u_gradphi( dphi_dxi[i][qp] );

            libMesh::Real u_diag_factor = _lambda_factor*this->_A*jac*tau(0,0)*dgradu_dt(0)*u_gradphi(0);
            libMesh::Real v_diag_factor = _lambda_factor*this->_A*jac*tau(0,0)*dgradv_dt(0)*u_gradphi(0);
            libMesh::Real w_diag_factor = _lambda_factor*this->_A*jac*tau(0,0)*dgradw_dt(0)*u_gradphi(0);

            const libMesh::Real C1 = _lambda_factor*this->_A*jac*C(0,0,0,0)*u_gradphi(0);

            const libMesh::Real gamma_u = (grad_x(0)+grad_u(0));
//.........这里部分代码省略.........

  void ElasticMembranePressure<PressureType>::element_time_derivative
  ( bool compute_jacobian, AssemblyContext & context )
  {
    unsigned int u_var = this->_disp_vars.u();
    unsigned int v_var = this->_disp_vars.v();
    unsigned int w_var = this->_disp_vars.w();

    const unsigned int n_u_dofs = context.get_dof_indices(u_var).size();

    const std::vector<libMesh::Real> &JxW =
      this->get_fe(context)->get_JxW();

    const std::vector<std::vector<libMesh::Real> >& u_phi =
      this->get_fe(context)->get_phi();

    const MultiphysicsSystem & system = context.get_multiphysics_system();

    unsigned int u_dot_var = system.get_second_order_dot_var(u_var);
    unsigned int v_dot_var = system.get_second_order_dot_var(v_var);
    unsigned int w_dot_var = system.get_second_order_dot_var(w_var);

    libMesh::DenseSubVector<libMesh::Number> &Fu = context.get_elem_residual(u_dot_var);
    libMesh::DenseSubVector<libMesh::Number> &Fv = context.get_elem_residual(v_dot_var);
    libMesh::DenseSubVector<libMesh::Number> &Fw = context.get_elem_residual(w_dot_var);

    libMesh::DenseSubMatrix<libMesh::Number>& Kuv = context.get_elem_jacobian(u_dot_var,v_var);
    libMesh::DenseSubMatrix<libMesh::Number>& Kuw = context.get_elem_jacobian(u_dot_var,w_var);

    libMesh::DenseSubMatrix<libMesh::Number>& Kvu = context.get_elem_jacobian(v_dot_var,u_var);
    libMesh::DenseSubMatrix<libMesh::Number>& Kvw = context.get_elem_jacobian(v_dot_var,w_var);

    libMesh::DenseSubMatrix<libMesh::Number>& Kwu = context.get_elem_jacobian(w_dot_var,u_var);
    libMesh::DenseSubMatrix<libMesh::Number>& Kwv = context.get_elem_jacobian(w_dot_var,v_var);

    unsigned int n_qpoints = context.get_element_qrule().n_points();

    // All shape function gradients are w.r.t. master element coordinates
    const std::vector<std::vector<libMesh::Real> >& dphi_dxi =
      this->get_fe(context)->get_dphidxi();

    const std::vector<std::vector<libMesh::Real> >& dphi_deta =
      this->get_fe(context)->get_dphideta();

    const libMesh::DenseSubVector<libMesh::Number>& u_coeffs = context.get_elem_solution( u_var );
    const libMesh::DenseSubVector<libMesh::Number>& v_coeffs = context.get_elem_solution( v_var );
    const libMesh::DenseSubVector<libMesh::Number>& w_coeffs = context.get_elem_solution( w_var );

    const std::vector<libMesh::RealGradient>& dxdxi  = this->get_fe(context)->get_dxyzdxi();
    const std::vector<libMesh::RealGradient>& dxdeta = this->get_fe(context)->get_dxyzdeta();

    for (unsigned int qp=0; qp != n_qpoints; qp++)
      {
        // sqrt(det(a_cov)), a_cov being the covariant metric tensor of undeformed body
        libMesh::Real sqrt_a = sqrt( dxdxi[qp]*dxdxi[qp]*dxdeta[qp]*dxdeta[qp]
                                     - dxdxi[qp]*dxdeta[qp]*dxdeta[qp]*dxdxi[qp] );

        // Gradients are w.r.t. master element coordinates
        libMesh::Gradient grad_u, grad_v, grad_w;
        for( unsigned int d = 0; d < n_u_dofs; d++ )
          {
            libMesh::RealGradient u_gradphi( dphi_dxi[d][qp], dphi_deta[d][qp] );
            grad_u += u_coeffs(d)*u_gradphi;
            grad_v += v_coeffs(d)*u_gradphi;
            grad_w += w_coeffs(d)*u_gradphi;
          }

        libMesh::RealGradient dudxi( grad_u(0), grad_v(0), grad_w(0) );
        libMesh::RealGradient dudeta( grad_u(1), grad_v(1), grad_w(1) );

        libMesh::RealGradient A_1 = dxdxi[qp] + dudxi;
        libMesh::RealGradient A_2 = dxdeta[qp] + dudeta;

        libMesh::RealGradient A_3 = A_1.cross(A_2);

        // Compute pressure at this quadrature point
        libMesh::Real press = (*_pressure)(context,qp);

        // Small optimization
        libMesh::Real p_over_sa = press/sqrt_a;

        /* The formula here is actually
           P*\sqrt{\frac{A}{a}}*A_3, where A_3 is a unit vector
           But, |A_3| = \sqrt{A} so the normalizing part kills
           the \sqrt{A} in the numerator, so we can leave it out
           and *not* normalize A_3.
        */
        libMesh::RealGradient traction = p_over_sa*A_3;

        for (unsigned int i=0; i != n_u_dofs; i++)
          {
            // Small optimization
            libMesh::Real phi_times_jac = u_phi[i][qp]*JxW[qp];

            Fu(i) -= traction(0)*phi_times_jac;
            Fv(i) -= traction(1)*phi_times_jac;
            Fw(i) -= traction(2)*phi_times_jac;

            if( compute_jacobian )
              {
                for (unsigned int j=0; j != n_u_dofs; j++)
//.........这里部分代码省略.........