摘要
提出了渐变非均匀交错网格高阶差分方法,模拟裂缝介质中瑞雷面波的传播过程,并引入具有二阶时间精度和六阶空间精度的附加差分公式解决非均匀交错网格的不对称问题.这种差分方法可描述为:在裂缝处采用细网格,在其他地方采用粗网格,细网格到粗网格之间在空间上采用渐变步长,达到既细致地描述了局部细微结构、又保持了计算量适当的目的.在变步长的选取中提出了采用汉宁窗函数,这样既可以较快地从粗网格向细网格过渡,又避免了粗细网格过渡时发生频散.算例表明该方法完全适用于模拟裂缝介质中瑞雷面波的传播,计算精度较高,且能节约时间和内存.数值模拟结果非常直观地揭示了瑞雷面波在裂缝介质中的波场传播特征.
A gradual change nonuniform staggered grids high order difference arithmetic was put forward, which simulates the propagation of Rayleigh wave in the interstice media, and successfully solves the asymmetry problems of nonuniform staggered grids by introducing additional difference formulas with two-order time and six-order spatial precision, This differeht way can be described as fine grids used in interstice and coarse grids in others. The steps from fine grids to coarse grids were gradually changed in space to describe local fine structure and to ensure proper calculations, Hanning window function was used to select the changing steps so that the transition from fine grids to coarse grids could be completed quickly. It also helps to avoid the frequency dispersion phenomena occurring in the transition process. The result of an example shows that this method is quite suitable to modeling of Rayleigh wave propagation in interstice media, not only accurate but also time-saving and memory-saving. The numerical modeling result shows the intuitive wave field characteristics of Rayleigh wave in interstice media.
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第8期24-28,共5页
Journal of Hunan University:Natural Sciences
基金
“十一五”国家科技支撑项目(2006BAC07B00)
江西省自然科学基金资助项目(05560003)
关键词
瑞雷面波
裂缝介质
非对称交错网格
汉宁窗
波场模拟
Rayleigh wave
interstice media
nonuniform graded staggered grids
Hanning window
modeling of wave fields
