Perlin Lourenço Panosso, Pinto Roberto Caldas de Andrade
Federal University of Santa Catarina, Campus Universitário, Trindade, CEP 88040-970, Florianópolis, Santa Catarina, Brazil.
Ultrasonics. 2019 Jul;96:185-195. doi: 10.1016/j.ultras.2019.01.007. Epub 2019 Jan 29.
The ultrasonic tomography is an important tool in nondestructive evaluation of concrete structures. It is usual to consider in ultrasonic reconstruction that the mechanical waves only propagate in straight-lines between the transmitter and the receiver transducers, corresponding to the behavior in a homogenous material. In a concrete specimen, however, mechanical waves may deviate from an internal flaw, which affects the resulting tomograms. In this study, the ray tracing technique based on the Network Theory, which allows to consider waves not travelling in a straight-line, was incorporated into the tomography processing. Experimental tests were carried out on concrete specimens with different internal flaws. The results indicated the importance of using the ray tracing technique to properly detect the size and the shape of internal flaws, improving the obtained tomograms. All the necessary algorithms for the application of the Network Theory were presented.
超声层析成像技术是混凝土结构无损检测的重要工具。在超声重建中，通常认为机械波仅在发射换能器和接收换能器之间沿直线传播，这与均匀材料中的传播行为相对应。然而，在混凝土试件中，机械波可能会从内部缺陷处发生偏离，这会影响最终的层析图像。在本研究中，基于网络理论的射线追踪技术被纳入层析成像处理中，该技术允许考虑波并非沿直线传播的情况。对具有不同内部缺陷的混凝土试件进行了实验测试。结果表明，使用射线追踪技术对于正确检测内部缺陷的尺寸和形状非常重要，可改善所获得的层析图像。文中还给出了应用网络理论所需的所有算法。
