Elastic wave propagation analysis using a curved two-dimensional spectral element

Element boundaries were treated as straight or plane in common spectral element, resulting in large errors in geometry approximation of structures with curve boundaries. In this paper, a sub-parametric plane spectral element was developed with a quadratic function for element shape interpolation. Any higher order than two functions can be used to interpolate element displacements field. The general procedure on establishment of a high order curved spectral element was discussed. A numerical example of elastic wave propagation in a rectangular plane structure was used to verify the proposed element. The analysis results were compared with the results given by straight spectral elements and classic finite elements. Then elastic wave propagation in a ring structure was analyzed by the proposed element and the common straight edge spectral element. The results show that there is larger discretion error using straight-edge element than curved-edge element for geometry approximation of complex structures with curve boundaries. Using the proposed curved-edge element in structural wave propagation will give better accuracy.