Method getDisplacementStrainMatrix

tools/Assembler/ref/Assembler2D.cpp:185–218

}

ZSparseMatrix Assembler2D::getDisplacementStrainMatrix() {
    typedef Eigen::Triplet<double> T;
    std::vector<T> triplets;

    for (size_t i=0; i<m_mesh->getNbrElements(); i++) {
        Eigen::MatrixXd dN = m_DN[i];
        VectorI idx = m_mesh->getElement(i);
        assert(idx.size() == 3);
        double V = m_mesh->getElementVolume(i);

        // e_xx
        size_t row = i * 3;
        for (size_t k=0; k<3; k++) {
            triplets.push_back(T(row, idx[k]*2, dN(k,0)));
        }

        // e_yy
        row++;
        for (size_t k=0; k<3; k++) {
            triplets.push_back(T(row, idx[k]*2+1, dN(k,1)));
        }

        // e_xy
        row++;
        for (size_t k=0; k<3; k++) {
            triplets.push_back(T(row, idx[k]*2  , dN(k,1) / 2.0));
            triplets.push_back(T(row, idx[k]*2+1, dN(k,0) / 2.0));
        }
    }

    Eigen::SparseMatrix<double> B = Eigen::SparseMatrix<double>(3*m_mesh->getNbrElements(), 2*m_mesh->getNbrNodes());
    B.setFromTriplets(triplets.begin(), triplets.end());
    return ZSparseMatrix(B);
}

ZSparseMatrix Assembler2D::getStrainStressMatrix() {
    typedef Eigen::Triplet<double> T;