simulation study on ultrasonic tomography for grouted reinforced concrete by finite element
来源期刊：中南大学学报(英文版)2015年第7期
论文作者：ZHU Zi-qiang YU Bo LI Ya-nan XIAO Jia-ying ZHOU Yong
文章页码：2791 - 2799
Key words：ultrasound computed tomography; nondestructive testing; concrete; exact field; finite element method
Abstract: A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures. In this algorithm, a hybrid regularizations-based iterative Newton method is implemented to provide stable inverse solutions. Furthermore, a dual mesh scheme and an adjoint method are adopted to reduce the computation cost and improve the efficiency of reconstruction. Simultaneous reconstruction of both acoustic velocity and attenuation coefficient for a reinforced concrete model is achieved with multiple frequency data. The algorithm is evaluated with numerical simulation under various practical scenarios including varied transmission/receiving modes, different noise levels, different source/detector numbers, and different contrast levels between the heterogeneity and background region. Results obtained suggest that the algorithm is insensitive to noise, and the reconstructions are quantitatively accurate in terms of the location, size and acoustic properties of the target over a range of contrast levels.
ZHU Zi-qiang(朱自强)1, YU Bo(喻波)1, 2, LI Ya-nan(李亚楠)1, XIAO Jia-ying(肖嘉莹)1, ZHOU Yong(周勇)1, 3
(1. School of Geosciences and Info-Physics Engineering, Central South University, Changsha 410083, China
2. Hunan Chaji Expressway Construction and Development Co., Ltd., Jishou 416000, China
3. College of Resource and Environment and Tourism, Hunan University of Arts and Science, Changde 415100, China)
Abstract:A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures. In this algorithm, a hybrid regularizations-based iterative Newton method is implemented to provide stable inverse solutions. Furthermore, a dual mesh scheme and an adjoint method are adopted to reduce the computation cost and improve the efficiency of reconstruction. Simultaneous reconstruction of both acoustic velocity and attenuation coefficient for a reinforced concrete model is achieved with multiple frequency data. The algorithm is evaluated with numerical simulation under various practical scenarios including varied transmission/receiving modes, different noise levels, different source/detector numbers, and different contrast levels between the heterogeneity and background region. Results obtained suggest that the algorithm is insensitive to noise, and the reconstructions are quantitatively accurate in terms of the location, size and acoustic properties of the target over a range of contrast levels.
Key words:ultrasound computed tomography; nondestructive testing; concrete; exact field; finite element method
