弹性波数值模拟的混合边界与频散抑制

英文篇名：Mixed boundary and frequency dispersion suppressing in elastic wave numerical simulation
中文刊名：煤田地质与勘探
英文刊名：Coal Geology & Exploration
作者：李庆春 ; 邵广周 ; 李斌
英文作者：LI Qing-chun~1 ; SHAO Guang-zhou~1 ; LI Bin~2(1. College of Geo-engineering and Surveying ; Chang'an University ; Xi′an 710054 ; China ; 2. Marine Geological Investigation Party ; Shanghai Offore Petroleum Bureau ; Shanghai 201208 ; China)
中文关键词：地震模型法 ; 数值模拟 ; 人工边界 ; 混合边界 ; 频散
英文关键词：seismic model ; numerical simulation ; artificial boundary ; mixed boundary ; frequency dispersion
出版日期：2005-08-25
机构：长安大学地测学院,长安大学地测学院,第一海洋地质调查大队陕西西安710054 ,陕西西安710054 ,上海201208
年：2005
期：04
出版单位：煤田地质与勘探

摘要

针对刚性边界条件、衰减边界条件与透射边界条件对弹性波场的影响及计算中产生的数值频散现象,将衰减边界与透射边界双重作用于人工边界,引入了混合边界条件,并在计算中采用了微量阻尼的方法,结果表明,混合边界条件能更好地吸收人工边界的反射;数值频散的阻尼算法能大大减弱由网格剖分、计算误差造成的频散现象。该方法可有效提高波场模拟精度。
Aiming at the effects of rigid boundary condition, attenuation boundary condition and transmitting boundary condition on elastic wave field and the numerical frequency dispersion in calculation, the writers apply attenuation boundary condition and transmitting boundary condition as a mixed boundary one on artificial boundary, introduce mixed boundary condition into elastic wave numerical simulation, and adopt micro-damp in the caculation at the same time. The results prove that mixed boundary condition is better in absorbing the reflection of artificial boundary. Besides, the micro-damp method used in the calculation of numerical frequency dispersion can weaken the frequency dispersion caused by the division of grid and the computational error. This method can improve the precision effectively in the wave field simulation.

引文

[1]范祯祥,等.地震波数值模拟与偏移成像[M].郑州:河南科学技术出版社,1994.
    [2]邵振海,洪伟,等.透射边界条件的统一理论[J].中国科学,2000,30(1):64-69.
    [3]廖振鹏.透射边界与无穷远辐射条件[J].中国科学(E辑),2001,31(3):254-262.
    [4]廖振鹏.近场波动的数值模拟[J].力学进展,1997,27(2):193-212.
    [5]房营光,莫海宏.有限元网格中波动的频散与稳定性的一种改进方法[J].地震工程与工程振动,2000,20(1):21-26·
    [6]Higdon RL.Absorbing boundaryconditionfor elastic waves[J].Geo-physics,1991,56(2):231-241.