基于辛几何逆时偏移成像的结构无损检测技术  

Structure nondestructive testing technology based on the symplectic geometry reverse-time migration imaging

作　　者：李忠芳[1] 杨拓宇[1] 

机构地区：[1]安徽科技学院机电与车辆工程学院,凤阳233100

出　　处：《地球物理学进展》2014年第6期2905-2909,共5页Progress in Geophysics

基　　金：安徽科技学院自然科学研究项目"基于任意传感器阵列的叠前偏移成像技术"(ZRC2014435);安徽省科技攻关计划重大项目"智能温室精准施肥控制技术集成与示范"(1301031030)联合资助

摘　　要：为了提高时域逆时偏移成像的计算精度,基于辛几何算法能获得半解析解精度结果的特点,结合逆时偏移成像条件构建了时域辛几何逆时偏移成像算法.首先,用有限元软件建立含缺陷结构和未知缺陷结构的有限元离散模型,然后用勒让德变换将二阶微分方程组变换成保辛的一阶微分方程组,用精细积分方法求解该一阶微分方程组;最后,基于逆时偏移成像条件,通过偏移叠加算法获得含缺陷结构的成像结果.结果表明,成像结果与预设缺陷吻合良好,该方法可以精确地检测出结构内部的缺陷.In order to improve the calculation accuracy of timedomain reverse-time migration imaging, based on the characteristics of semi-analytical solution precision results of the symplectic geometric algorithm,we build the reverse-time migration imaging algorithm based on time-domain symplectic geometry combination of reverse-time migration imaging conditions.First of all,we establish finite element discrete model of a structure containing defects and an unknown defect structure by using finite element software,and put the second order differential equations into the first order differential equations with Legendre transformation,and then solve the first-order differential equations with the precise integration method;Finally,we obtain the imaging results of the structure containing defects with the imaging condition of reverse-time migration and migration stack algorithm.The results show that the imaging results are in good agreement with those obtained with the default defect,the method can accurately detect the defects within the structure.

关 键 词：辛几何 逆时偏移成像 数值模拟 

分 类 号：TB553[理学—物理]