Properties of second-order edge elements

This paper discusses properties of the second-order edge elements for the finite element analysis. It is shown that the condition number, which dominates the convergence of the ICCG method, can be different even for the equivalent second-order elements which have common basis vectors. Moreover the computed eigenvalues and condition numbers of the local and global stiffness matrices are shown to be consistent with the reported convergence of the ICCG method. It is suggested that the spectrum of the local stiffness matrix is useful for prediction of the ICCG convergence.