Application of Contourlet Transform in Damage Localization and Severity Assessment of Prestressed Concrete Slabs

چکیده مقاله

In this paper, the location and severity of damages in prestressed concrete slabs are assessed using the contourlet transform as a novel signal processing method. To achieve this goal, the numerical models of prestressed concrete slabs were built based on the experimental specimens reported in the previous research works. Then, the single, double, and triple damage scenarios with various geometric shapes (transverse, longitudinal, inclined, and curved slots) at different positions (middle and corners) were created in the models. To assess the severity of damages, the depth of slots was taken constant in the single and double damage scenarios and assumed variable in the triple ones. The vibration mode shapes together with their corresponding curvatures were obtained using the modal analysis. The contourlet transform coefficients of modal curvatures in two states of damaged and undamaged models were taken as the inputs for the proposed damage index. The results show that the proposed damage index has well identified the severity of triple damage scenarios in addition to detecting the location of different single and double damages at the middle and in the vicinity of corner and supports of the prestressed concrete slab models. Furthermore, the proposed damage index has the highest sensitivity rate to damage scenarios with geometric shapes of inclined, curved, transverse, and longitudinal slot, respectively.