Numerical Modeling and Experimental Verification on the Aggregate and Boundary Effects Induced in Defect Scanning with Stress Wave and Synthetic Aperture Focusing Methods

• Main Authors: Chin-Lung Chiu, 邱進隆
• Other Authors: Shu-Tao Liao
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/15540161206593270804

碩士 === 中華大學 === 土木與工程資訊學系碩士班 === 95 === The application of a nondestructive testing technology to evaluate the defects embedded in concrete structures is proposed in this paper. Based on using transient elastic waves in conjunction of the Synthetic Aperture Focusing method, the defects implied in concrete may be presented with the scanning images. In this study, the propagation of elastic waves was first simulated with the numerical method of Finite Element. The collected response data was then processed with the Synthetic Aperture Focusing method so that the geometric information of the embedded defects may be presented with gray-scaled images. The numerical models were also changed in this study to investigate the factors that affect the resolution of tests. Finally, concrete specimen with a void was cast for the experiment of scanning the defect. The experimental results not only presented the high potential of this method in practical application, but also verified the correctness of the numerical models so that this finite element model may be used as the tool to carry out vast kinds of parametric studies. Besides, the effect of the re-bars on the scanning results will also be roughly studied in this research.