diff --git a/src/harmonicenergystiffness.hh b/src/harmonicenergystiffness.hh index 10b1ecfb6b355572ddb041d8a89d754bfa4cf941..a3f30e4eb0183c2895f0f66cb0a98ec8e34ceb7c 100644 --- a/src/harmonicenergystiffness.hh +++ b/src/harmonicenergystiffness.hh @@ -9,9 +9,7 @@ template<class GridView, class TargetSpace> class HarmonicEnergyLocalStiffness - : public Dune::LocalStiffness<GridView, - TargetSpace::TangentVector::field_type, - TargetSpace::TangentVector::size> + : public Dune::LocalGeodesicFEStiffness<GridView,TargetSpace> { // grid types typedef typename GridView::Grid::ctype DT; @@ -19,22 +17,12 @@ class HarmonicEnergyLocalStiffness typedef typename GridView::template Codim<0>::EntityPointer EntityPointer; // some other sizes - enum {dim=GridView::dimension}; - - // Quadrature order used for the extension and shear energy - enum {shearQuadOrder = 2}; - - // Quadrature order used for the bending and torsion energy - enum {bendingQuadOrder = 2}; + enum {gridDim=GridView::dimension}; public: - //! Each block is x, y, theta in 2d, T (R^3 \times SO(3)) in 3d - enum { blocksize = 6 }; - - // define the number of components of your system, this is used outside - // to allocate the correct size of (dense) blocks with a FieldMatrix - enum {m=blocksize}; + //! Dimension of a tangent space + enum { blocksize = TargetSpace::TangentVector::size }; // types for matrics, vectors and boundary conditions typedef Dune::FieldMatrix<RT,m,m> MBlockType; // one entry in the stiffness matrix @@ -42,28 +30,10 @@ public: typedef Dune::array<Dune::BoundaryConditions::Flags,m> BCBlockType; // componentwise boundary conditions //! Default Constructor - RodLocalStiffness () + HarmonicEnergyLocalStiffness () {} - //! Default Constructor - RodLocalStiffness (const Dune::array<double,3>& K, const Dune::array<double,3>& A) - { - for (int i=0; i<3; i++) { - K_[i] = K[i]; - A_[i] = A[i]; - } - } - - //! assemble local stiffness matrix for given element and order - /*! On exit the following things have been done: - - The stiffness matrix for the given entity and polynomial degree has been assembled and is - accessible with the mat() method. - - The boundary conditions have been evaluated and are accessible with the bc() method - - The right hand side has been assembled. It contains either the value of the essential boundary - condition or the assembled source term and neumann boundary condition. It is accessible via the rhs() method. - @param[in] e a codim 0 entity reference - \param[in] localSolution Current local solution, because this is a nonlinear assembler - @param[in] k order of Lagrange basis + /** \brief assemble local stiffness matrix for given element */ void assemble (const Entity& e, const Dune::BlockVector<Dune::FieldVector<double, 6> >& localSolution, @@ -72,12 +42,6 @@ public: DUNE_THROW(Dune::NotImplemented, "!"); } - /** \todo Remove this once this methods is not in base class LocalStiffness anymore */ - void assemble (const Entity& e, int k=1) - { - DUNE_THROW(Dune::NotImplemented, "!"); - } - void assembleBoundaryCondition (const Entity& e, int k=1) { DUNE_THROW(Dune::NotImplemented, "!"); @@ -85,19 +49,7 @@ public: RT energy (const Entity& e, - const Dune::array<RigidBodyMotion<3>,2>& localSolution, - const Dune::array<RigidBodyMotion<3>,2>& localReferenceConfiguration, - int k=1); - - static void interpolationDerivative(const Rotation<3,RT>& q0, const Rotation<3,RT>& q1, double s, - Dune::array<Quaternion<double>,6>& grad); - - static void interpolationVelocityDerivative(const Rotation<3,RT>& q0, const Rotation<3,RT>& q1, double s, - double intervalLength, Dune::array<Quaternion<double>,6>& grad); - - Dune::FieldVector<double, 6> getStrain(const Dune::array<RigidBodyMotion<3>,2>& localSolution, - const Entity& element, - const Dune::FieldVector<double,1>& pos) const; + const Dune::array<RigidBodyMotion<3>,2>& localSolution) const; /** \brief Assemble the element gradient of the energy functional */ void assembleGradient(const Entity& element, @@ -105,26 +57,12 @@ public: const Dune::array<RigidBodyMotion<3>,2>& referenceConfiguration, Dune::array<Dune::FieldVector<double,6>, 2>& gradient) const; - template <class T> - static Dune::FieldVector<T,3> darboux(const Rotation<3,T>& q, const Dune::FieldVector<T,4>& q_s) - { - Dune::FieldVector<double,3> u; // The Darboux vector - - u[0] = 2 * (q.B(0) * q_s); - u[1] = 2 * (q.B(1) * q_s); - u[2] = 2 * (q.B(2) * q_s); - - return u; - } - }; template <class GridType, class RT> RT RodLocalStiffness<GridType, RT>:: energy(const Entity& element, - const Dune::array<RigidBodyMotion<3>,2>& localSolution, - const Dune::array<RigidBodyMotion<3>,2>& localReferenceConfiguration, - int k) + const Dune::array<RigidBodyMotion<3>,2>& localSolution) const { RT energy = 0; @@ -181,482 +119,5 @@ energy(const Entity& element, return energy; } - -template <class GridType, class RT> -void RodLocalStiffness<GridType, RT>:: -interpolationDerivative(const Rotation<3,RT>& q0, const Rotation<3,RT>& q1, double s, - Dune::array<Quaternion<double>,6>& grad) -{ - // Clear output array - for (int i=0; i<6; i++) - grad[i] = 0; - - // The derivatives with respect to w^1 - - // Compute q_1^{-1}q_0 - Rotation<3,RT> q1InvQ0 = q1; - q1InvQ0.invert(); - q1InvQ0 = q1InvQ0.mult(q0); - - { - // Compute v = (1-s) \exp^{-1} ( q_1^{-1} q_0) - Dune::FieldVector<RT,3> v = Rotation<3,RT>::expInv(q1InvQ0); - v *= (1-s); - - Dune::FieldMatrix<RT,4,3> dExp_v = Rotation<3,RT>::Dexp(v); - - Dune::FieldMatrix<RT,3,4> dExpInv = Rotation<3,RT>::DexpInv(q1InvQ0); - - Dune::FieldMatrix<RT,4,4> mat(0); - for (int i=0; i<4; i++) - for (int j=0; j<4; j++) - for (int k=0; k<3; k++) - mat[i][j] += (1-s) * dExp_v[i][k] * dExpInv[k][j]; - - for (int i=0; i<3; i++) { - - Quaternion<RT> dw; - for (int j=0; j<4; j++) - dw[j] = 0.5 * (i==j); // dExp[j][i] at v=0 - - dw = q1InvQ0.mult(dw); - - mat.umv(dw,grad[i]); - grad[i] = q1.mult(grad[i]); - - } - } - - - // The derivatives with respect to w^1 - - // Compute q_0^{-1} - Rotation<3,RT> q0InvQ1 = q0; - q0InvQ1.invert(); - q0InvQ1 = q0InvQ1.mult(q1); - - { - // Compute v = s \exp^{-1} ( q_0^{-1} q_1) - Dune::FieldVector<RT,3> v = Rotation<3,RT>::expInv(q0InvQ1); - v *= s; - - Dune::FieldMatrix<RT,4,3> dExp_v = Rotation<3,RT>::Dexp(v); - - Dune::FieldMatrix<RT,3,4> dExpInv = Rotation<3,RT>::DexpInv(q0InvQ1); - - Dune::FieldMatrix<RT,4,4> mat(0); - for (int i=0; i<4; i++) - for (int j=0; j<4; j++) - for (int k=0; k<3; k++) - mat[i][j] += s * dExp_v[i][k] * dExpInv[k][j]; - - for (int i=3; i<6; i++) { - - Quaternion<RT> dw; - for (int j=0; j<4; j++) - dw[j] = 0.5 * ((i-3)==j); // dExp[j][i-3] at v=0 - - dw = q0InvQ1.mult(dw); - - mat.umv(dw,grad[i]); - grad[i] = q0.mult(grad[i]); - - } - } -} - - - -template <class GridType, class RT> -void RodLocalStiffness<GridType, RT>:: -interpolationVelocityDerivative(const Rotation<3,RT>& q0, const Rotation<3,RT>& q1, double s, - double intervalLength, Dune::array<Quaternion<double>,6>& grad) -{ - // Clear output array - for (int i=0; i<6; i++) - grad[i] = 0; - - // Compute q_0^{-1} - Rotation<3,RT> q0Inv = q0; - q0Inv.invert(); - - - // Compute v = s \exp^{-1} ( q_0^{-1} q_1) - Dune::FieldVector<RT,3> v = Rotation<3,RT>::expInv(q0Inv.mult(q1)); - v *= s/intervalLength; - - Dune::FieldMatrix<RT,4,3> dExp_v = Rotation<3,RT>::Dexp(v); - - Dune::array<Dune::FieldMatrix<RT,3,3>, 4> ddExp; - Rotation<3,RT>::DDexp(v, ddExp); - - Dune::FieldMatrix<RT,3,4> dExpInv = Rotation<3,RT>::DexpInv(q0Inv.mult(q1)); - - Dune::FieldMatrix<RT,4,4> mat(0); - for (int i=0; i<4; i++) - for (int j=0; j<4; j++) - for (int k=0; k<3; k++) - mat[i][j] += 1/intervalLength * dExp_v[i][k] * dExpInv[k][j]; - - - // ///////////////////////////////////////////////// - // The derivatives with respect to w^0 - // ///////////////////////////////////////////////// - for (int i=0; i<3; i++) { - - // \partial exp \partial w^1_j at 0 - Quaternion<RT> dw; - for (int j=0; j<4; j++) - dw[j] = 0.5*(i==j); // dExp_v_0[j][i]; - - // \xi = \exp^{-1} q_0^{-1} q_1 - Dune::FieldVector<RT,3> xi = Rotation<3,RT>::expInv(q0Inv.mult(q1)); - - Quaternion<RT> addend0; - addend0 = 0; - dExp_v.umv(xi,addend0); - addend0 = dw.mult(addend0); - addend0 /= intervalLength; - - // \parder{\xi}{w^1_j} = ... - Quaternion<RT> dwConj = dw; - dwConj.conjugate(); - //dwConj[3] -= 2 * dExp_v_0[3][i]; the last row of dExp_v_0 is zero - dwConj = dwConj.mult(q0Inv.mult(q1)); - - Dune::FieldVector<RT,3> dxi(0); - Rotation<3,RT>::DexpInv(q0Inv.mult(q1)).umv(dwConj, dxi); - - Quaternion<RT> vHv; - for (int j=0; j<4; j++) { - vHv[j] = 0; - // vHv[j] = dxi * DDexp * xi - for (int k=0; k<3; k++) - for (int l=0; l<3; l++) - vHv[j] += ddExp[j][k][l]*dxi[k]*xi[l]; - } - - vHv *= s/intervalLength/intervalLength; - - // Third addend - mat.umv(dwConj,grad[i]); - - // add up - grad[i] += addend0; - grad[i] += vHv; - - grad[i] = q0.mult(grad[i]); - } - - - // ///////////////////////////////////////////////// - // The derivatives with respect to w^1 - // ///////////////////////////////////////////////// - for (int i=3; i<6; i++) { - - // \partial exp \partial w^1_j at 0 - Quaternion<RT> dw; - for (int j=0; j<4; j++) - dw[j] = 0.5 * ((i-3)==j); // dw[j] = dExp_v_0[j][i-3]; - - // \xi = \exp^{-1} q_0^{-1} q_1 - Dune::FieldVector<RT,3> xi = Rotation<3,RT>::expInv(q0Inv.mult(q1)); - - // \parder{\xi}{w^1_j} = ... - Dune::FieldVector<RT,3> dxi(0); - dExpInv.umv(q0Inv.mult(q1.mult(dw)), dxi); - - Quaternion<RT> vHv; - for (int j=0; j<4; j++) { - // vHv[j] = dxi * DDexp * xi - vHv[j] = 0; - for (int k=0; k<3; k++) - for (int l=0; l<3; l++) - vHv[j] += ddExp[j][k][l]*dxi[k]*xi[l]; - } - - vHv *= s/intervalLength/intervalLength; - - // /////////////////////////////////// - // second addend - // /////////////////////////////////// - - - dw = q0Inv.mult(q1.mult(dw)); - - mat.umv(dw,grad[i]); - grad[i] += vHv; - - grad[i] = q0.mult(grad[i]); - - } - -} - -template <class GridType, class RT> -Dune::FieldVector<double, 6> RodLocalStiffness<GridType, RT>:: -getStrain(const Dune::array<RigidBodyMotion<3>,2>& localSolution, - const Entity& element, - const Dune::FieldVector<double,1>& pos) const -{ - if (!element.isLeaf()) - DUNE_THROW(Dune::NotImplemented, "Only for leaf elements"); - - assert(localSolution.size() == 2); - - // Strain defined on each element - Dune::FieldVector<double, 6> strain(0); - - // Extract local solution on this element - const Dune::LagrangeShapeFunctionSet<double, double, 1> & baseSet - = Dune::LagrangeShapeFunctions<double, double, 1>::general(element.type(), 1); - int numOfBaseFct = baseSet.size(); - - const Dune::FieldMatrix<double,1,1>& inv = element.geometry().jacobianInverseTransposed(pos); - - // /////////////////////////////////////// - // Compute deformation gradient - // /////////////////////////////////////// - Dune::FieldVector<double,1> shapeGrad[numOfBaseFct]; - - for (int dof=0; dof<numOfBaseFct; dof++) { - - for (int i=0; i<1; i++) - shapeGrad[dof][i] = baseSet[dof].evaluateDerivative(0,i,pos); - - // multiply with jacobian inverse - Dune::FieldVector<double,1> tmp(0); - inv.umv(shapeGrad[dof], tmp); - shapeGrad[dof] = tmp; - - } - - // ////////////////////////////////// - // Interpolate - // ////////////////////////////////// - - Dune::FieldVector<double,3> r_s; - for (int i=0; i<3; i++) - r_s[i] = localSolution[0].r[i]*shapeGrad[0][0] + localSolution[1].r[i]*shapeGrad[1][0]; - - // Interpolate the rotation at the quadrature point - Rotation<3,double> q = Rotation<3,double>::interpolate(localSolution[0].q, localSolution[1].q, pos); - - // Get the derivative of the rotation at the quadrature point by interpolating in $H$ - Quaternion<double> q_s = Rotation<3,double>::interpolateDerivative(localSolution[0].q, localSolution[1].q, - pos); - // Transformation from the reference element - q_s *= inv[0][0]; - - // ///////////////////////////////////////////// - // Sum it all up - // ///////////////////////////////////////////// - - // Part I: the shearing and stretching strain - strain[0] = r_s * q.director(0); // shear strain - strain[1] = r_s * q.director(1); // shear strain - strain[2] = r_s * q.director(2); // stretching strain - - // Part II: the Darboux vector - - Dune::FieldVector<double,3> u = darboux(q, q_s); - - strain[3] = u[0]; - strain[4] = u[1]; - strain[5] = u[2]; - - return strain; -} - -template <class GridType, class RT> -void RodLocalStiffness<GridType, RT>:: -assembleGradient(const Entity& element, - const Dune::array<RigidBodyMotion<3>,2>& solution, - const Dune::array<RigidBodyMotion<3>,2>& referenceConfiguration, - Dune::array<Dune::FieldVector<double,6>, 2>& gradient) const -{ - using namespace Dune; - - // Extract local solution on this element - const Dune::LagrangeShapeFunctionSet<double, double, 1> & baseSet - = Dune::LagrangeShapeFunctions<double, double, 1>::general(element.type(), 1); // first order - const int numOfBaseFct = baseSet.size(); - - // init - for (size_t i=0; i<gradient.size(); i++) - gradient[i] = 0; - - double intervalLength = element.geometry().corner(1)[0] - element.geometry().corner(0)[0]; - - // /////////////////////////////////////////////////////////////////////////////////// - // Reduced integration to avoid locking: assembly is split into a shear part - // and a bending part. Different quadrature rules are used for the two parts. - // This avoids locking. - // /////////////////////////////////////////////////////////////////////////////////// - - // Get quadrature rule - const QuadratureRule<double, 1>& shearingQuad = QuadratureRules<double, 1>::rule(element.type(), shearQuadOrder); - - for (int pt=0; pt<shearingQuad.size(); pt++) { - - // Local position of the quadrature point - const FieldVector<double,1>& quadPos = shearingQuad[pt].position(); - - const FieldMatrix<double,1,1>& inv = element.geometry().jacobianInverseTransposed(quadPos); - const double integrationElement = element.geometry().integrationElement(quadPos); - - double weight = shearingQuad[pt].weight() * integrationElement; - - // /////////////////////////////////////// - // Compute deformation gradient - // /////////////////////////////////////// - double shapeGrad[numOfBaseFct]; - - for (int dof=0; dof<numOfBaseFct; dof++) { - - shapeGrad[dof] = baseSet[dof].evaluateDerivative(0,0,quadPos); - - // multiply with jacobian inverse - FieldVector<double,1> tmp(0); - inv.umv(shapeGrad[dof], tmp); - shapeGrad[dof] = tmp; - - } - - // ////////////////////////////////// - // Interpolate - // ////////////////////////////////// - - FieldVector<double,3> r_s; - for (int i=0; i<3; i++) - r_s[i] = solution[0].r[i]*shapeGrad[0] + solution[1].r[i]*shapeGrad[1]; - - // Interpolate current rotation at this quadrature point - Rotation<3,double> q = Rotation<3,double>::interpolate(solution[0].q, solution[1].q,quadPos[0]); - - // The current strain - FieldVector<double,blocksize> strain = getStrain(solution, element, quadPos); - - // The reference strain - FieldVector<double,blocksize> referenceStrain = getStrain(referenceConfiguration, element, quadPos); - - - // dd_dvij[m][i][j] = \parder {(d_k)_i} {q} - array<FieldMatrix<double,3 , 4>, 3> dd_dq; - q.getFirstDerivativesOfDirectors(dd_dq); - - // First derivatives of the position - array<Quaternion<double>,6> dq_dwij; - interpolationDerivative(solution[0].q, solution[1].q, quadPos, dq_dwij); - - // ///////////////////////////////////////////// - // Sum it all up - // ///////////////////////////////////////////// - - for (int i=0; i<numOfBaseFct; i++) { - - // ///////////////////////////////////////////// - // The translational part - // ///////////////////////////////////////////// - - // \partial \bar{W} / \partial r^i_j - for (int j=0; j<3; j++) { - - for (int m=0; m<3; m++) - gradient[i][j] += weight - * ( A_[m] * (strain[m] - referenceStrain[m]) * shapeGrad[i] * q.director(m)[j]); - - } - - // \partial \bar{W}_v / \partial v^i_j - for (int j=0; j<3; j++) { - - for (int m=0; m<3; m++) { - FieldVector<double,3> tmp(0); - dd_dq[m].umv(dq_dwij[3*i+j], tmp); - gradient[i][3+j] += weight - * A_[m] * (strain[m] - referenceStrain[m]) * (r_s*tmp); - } - } - - } - - } - - // ///////////////////////////////////////////////////// - // Now: the bending/torsion part - // ///////////////////////////////////////////////////// - - // Get quadrature rule - const QuadratureRule<double, 1>& bendingQuad = QuadratureRules<double, 1>::rule(element.type(), bendingQuadOrder); - - for (int pt=0; pt<bendingQuad.size(); pt++) { - - // Local position of the quadrature point - const FieldVector<double,1>& quadPos = bendingQuad[pt].position(); - - const FieldMatrix<double,1,1>& inv = element.geometry().jacobianInverseTransposed(quadPos); - const double integrationElement = element.geometry().integrationElement(quadPos); - - double weight = bendingQuad[pt].weight() * integrationElement; - - // Interpolate current rotation at this quadrature point - Rotation<3,double> q = Rotation<3,double>::interpolate(solution[0].q, solution[1].q,quadPos[0]); - - // Get the derivative of the rotation at the quadrature point by interpolating in $H$ - Quaternion<double> q_s = Rotation<3,double>::interpolateDerivative(solution[0].q, solution[1].q, - quadPos); - // Transformation from the reference element - q_s *= inv[0][0]; - - - // The current strain - FieldVector<double,blocksize> strain = getStrain(solution, element, quadPos); - - // The reference strain - FieldVector<double,blocksize> referenceStrain = getStrain(referenceConfiguration, element, quadPos); - - // First derivatives of the position - array<Quaternion<double>,6> dq_dwij; - interpolationDerivative(solution[0].q, solution[1].q, quadPos, dq_dwij); - - array<Quaternion<double>,6> dq_ds_dwij; - interpolationVelocityDerivative(solution[0].q, solution[1].q, quadPos[0]*intervalLength, intervalLength, - dq_ds_dwij); - - // ///////////////////////////////////////////// - // Sum it all up - // ///////////////////////////////////////////// - - for (int i=0; i<numOfBaseFct; i++) { - - // ///////////////////////////////////////////// - // The rotational part - // ///////////////////////////////////////////// - - // \partial \bar{W}_v / \partial v^i_j - for (int j=0; j<3; j++) { - - for (int m=0; m<3; m++) { - - // Compute derivative of the strain - /** \todo Is this formula correct? It seems strange to call - B(m) for a _derivative_ of a rotation */ - double du_dvij_m = 2 * (dq_dwij[i*3+j].B(m) * q_s) - + 2* ( q.B(m) * dq_ds_dwij[i*3+j]); - - // Sum it up - gradient[i][3+j] += weight * K_[m] - * (strain[m+3]-referenceStrain[m+3]) * du_dvij_m; - - } - - } - - } - - } -} - #endif