A note for the mechanism of high-frequency oscillation instability resulted from absorbing boundary conditions

• 来源期刊: 地震学报（英文版）
• 学科: 地球科学
• 年，卷（期）: 2008,（3）
• 页码范围: 306-310
• 页数: 5页
• 分类号: P315.9
• 语种: 英文

摘要

In this paper the explanation of the mechanism of high-frequency oscillation instability resulted from absorbing boundary conditions is further improved. And we analytically prove the proposition that for one dimensional dis- crete model of elastic wave motion, the module of reflection factor will be greater than 1 in high frequency band when artificial wave velocity is greater than 1.5 times the ratio of discrete space step to discrete time step. Based on the proof, the frequency band in which instability occurs is discussed in detail, showing such high-frequency waves are meaningless for the numerical simulation of wave motion.