由于在波动切比雪夫谱元模拟中使用隐式时间积分方法存在计算效率较低、不易施加边界条件以及波动输入不便的问题,而中心差分法是能够平衡精度和计算效率的较优选择,并以一维波动模型探讨相应的波动输入方法和时域积分稳定条件。通过输入Ricker子波以及复合正弦波的数值算例证实了方法的有效性,并接着分析不同计算参数对模拟精度的影响。结果表明:空间上一个最短波长尺度内的谱元节点数、单元阶次分别取不低于5和4时能够达到比较理想的精度,而时间步长变化对精度的影响不大。
If an implicit time integration method was employed in Chebyshev spectral element simulation of wave motion,it would lead to lower computation efficiency and difficulties of implementing boundary conditions and applying incident waves.Then the advantages of central difference method,which may keep a good balance between accuracy and efficiency,were discussed,and the corresponding wave input method and stability criterion of time-domain integration were also investigated.The method was examined by one-dimensional numerical simulations with incident Ricker wavelet and composite sine waves,and then the influences of computation parameters on the accuracy were analyzed.Computation results indicated that when the number of spectral element nodes in one minimum spatial wavelength and the element order were not lower than 5 and 4,respectively,desired accuracy could be achieved,while the variation of time step had little influence on the accuracy.