[S-TT47] ハイパフォーマンスコンピューティングが拓く固体地球科学の未来

[STT47-03] 弾性波計算のための最適スペクトル要素法

*長谷川 慶¹、冨士 延章²、小西 健介³ (1.東京大学地震研究所、2.パリ地球物理研究所、3.台湾中央研究院地球科学研究所)

キーワード：弾性波、数値解析、有限要素法、スペクトル要素法、誤差最適化、計算地震学

We introduce new numerical integration operators which compose the mass and stiffness matrices of a modified spectral element method for simulation of elastic wave propagation. While these operators use the same quadrature nodes as does the original spectral element method, they are designed in order that their lower-order contributions to the numerical dispersion error cancel each other. As a result, the modified spectral element method yields two extra-orders of accuracy, and is comparable to the original method of one order higher. The theoretical results are confirmed by numerical dispersion analysis and examples of computation of waveforms using our operators. Replacing the ordinary operators by those proposed in this study could be a non-expensive solution to improve the accuracy.

*この発表の内容はComputer Methods in Applied Mechanics and Engineeringに掲載されています(doi: 10.1016/j.cma.2018.07.025)