中南大学学报（自然科学版）2012，Vol.43Issue(5)：1871-1876,6.
基于叠前逆时偏移技术的Lamb波多损伤探测
Lamb wave detection of multiple damages based on prestack reverse time migration
摘要
Abstract
A migration technique used in geophysical exploration to interpret the backscattering wave field and to image the flaws in the structure is proved to be an effective method detecting and imaging multiple damages in a plate structure. A structural health monitoring system (SHMS) with integrated actuators/sensors can be used to activate and receive lowest-order antisymmetric Lamb waves. The proposed approach is executed by a two-dimensional finite difference method both in simulating the reflection waves and in implementing the prestack migration. An analytical solution based on Mindlin plate theory is utilized to verify the accuracy of the numerical algorithm. An excitation-time imaging condition is presented based on the ray tracing concept, and prestack reverse-time migration is executed to propagate the reflection energy back to the damages. The plate is imaged in terms of the transverse deformation velocity after migration is executed. Thus the dimensions, locations and seriousness of the damages can be displayed visually. Numerical examples show that multiple damages can be detected effectively and the image of the damages correlates with the characters of target damages.关键词
多重损伤/Lamb波/叠前逆时偏移技术/Mindlin板理论/快照技术Key words
multiple damage/ Lamb wave/ prestack reverse-time migration/ Mindlin plate theory/ snapshot分类
建筑与水利引用本文复制引用
郭原草,郭少华..基于叠前逆时偏移技术的Lamb波多损伤探测[J].中南大学学报（自然科学版）,2012,43(5):1871-1876,6.基金项目
国家自然科学基金资助项目(50778179) （50778179）
