On the Symmetric Damage Detection with Flexural Waves using Circular Piezoelectric Transducers

The design of structural health monitoring (SHM) systems usually involves the selection of actuators and sensors, defining their positions on the structure, and post-processing output signals. The definition of the characteristics of the excitation signals before investigating the structural condition is also an important task to be considered to establish a damage detection process. In this context, the present article introduces an approach to determine the optimal parameters to detect symmetric damage in plates when considering perpendicular incidence of flexural waves in the damage. Circular piezoelectric transducers are applied to create and measure the waves. Optimal frequencies to detect the damage, create and measure the flexural waves are observed, which are described in terms of the properties of damage and the piezoelectric transducers, and these frequencies must be close to guarantee good damage detectability. Experimental tests are carried out by considering a rectangular aluminum plate with circular piezoelectric transducers coupled to its surface. Experimental results demonstrate the proposed approach, and the results show that it contributes to establishing more efficient SHM systems.