Multitype Damage Imaging in Concrete Modeling Based on Time Reversal Technique

It is necessary to develop effective methods for visually detecting concrete damage because minor damage can affect the performance of concrete materials. However, the non-homogeneous nature of concrete materials limits the application of imaging algorithms that have been widely used in aerospace and mechanical fields; thus, obtaining high-resolution imaging maps is difficult. In this study, feasibility research on concrete damage detection was conducted using the time reversal focusing imaging algorithm. A new method for characterizing various concrete damage conditions with focusing curves was proposed. ABAQUS software was utilized to establish five types of concrete damage, and the imaging quality of the proposed method was evaluated in Python. The effect of the relative position of the damage and the sensors was analyzed. The focusing curve was extracted from the imaging area to further explain the image information. The numerical simulation results show that time reversal focusing had better damage localization than the forward algorithm; time focusing also improved the spatial focusing quality. In addition, focusing curves were used to extract information from the main lobe and to determine the size and location of the damage.