Efficient TDFEM schemes with second-order PML based on different temporal basis functions

The time domain finite element method (TDFEM) formulations have been presented using two kinds of temporal basis functions, B-spline and Lagrange interpolation polynomial, and the computational domain is truncated with second-order perfectly matched layer (PML). This is motivated by utilising good interpolation features of these temporal basis functions and better absorption performances of second-order PMLs. Numerical cases demonstrate that the proposed TDFEM schemes achieve more accurate results with about 5% to 7% increase of run time and 1.5% increase of memory usage compared with the TDFEM scheme with Sacks PML. However, the presented TDFEM schemes merely require 1/6th of the total run time for frequency domain FEM.