Improving the Newmark time integration scheme in finite element time domain methods

摘要

The Newmark formulation for the time-stepping solution of the electric field vector wave equation is modified in order to suppress low-frequency spurious responses. It is verified that the proposed method has the advantage of halving the number of iterations necessary to solve the system of linear equations and it is shown that setting the number of iterations per time step can be more convenient than establishing a residual tolerance to verify convergence. In addition, the use of diagonal and incomplete Cholesky preconditioners are tested through numerical examples and they appear to be equivalent in terms of CPU time, leaving the first as the preferable choice concerning memory storage and programing facilities.