基于离散粒子理论地震波传播数值模拟网格剖分计算方法

Mesh generation calculation method based on discrete particle scheme for numerical modeling seismic waves

介绍一种基于离散粒子理论地震波传播数值模拟的网格剖分计算方法.根据离散粒子理论,将研究区域划分为由一系列相互作用的粒子组成的正六边形网格,这些粒子在它们的接触点处发生相互作用,并用Hooke定律和Newton定律描述.为解决六边形网格带来的网格交错而难以计算以及波场输出问题,将横向网格进行加密,加密处赋予假想的粒子,输出波场时选取偶数行偶数列点或奇数行奇数列点的波场值.均匀介质和层状介质模型的数值模拟结果表明,该网格剖分计算方法能够将离散粒子理论用于模拟弹性波在非均匀各向同性介质中地震波的传播.

A mesh generation calculation method based on discrete particle scheme for numerical modeling seismic waves is presented. According to the discrete particle theory, the study area can be divided into regular hexagon grid composed of a series of interacting particles. These particles interact at their contact points and the motion of particles in space is described by Hook＇s Law and Newton＇s Law. To solve the problem of the grid crisscross brought by hexagon grids which may lead to difficulty in calculation and output wave field＇s value, we encrypt the imaginary particles at the horizontal grids and output the wave field value of the even lines＂ points in the even column or odd lines＂ points in odd column. The numerical simulation results of homogeneous model and layer model proved that this mesh generation calculation method based on discrete particle theory is capable of modeling the propagation of elastic waves through heterogeneous isotropic media.