Identification of an elliptic void in a piezoelectric layer by two types of loads

Abstract

This study investigates the effect of mechanical load and electric voltage on the scattering waves of a buried object in a piezoelectric layer, added to that, the study examines the detection of the buried object through its scattering surface waves. The procedure of the study includes two cases which include two steps each. During step 1 of case 1, the researchers applied a periodic mechanical load upon layer containing an elliptic void, where the size and location are predetermined. A system of coupled boundary integral equations utilizing the generalized Green’s identity and the reciprocal work theorem is formulated. The boundary element method supported by Green’s functions was employed to solve the formulated integral equations. Hence, the deformation and electric potential over the object’s contour are identified. Step 2 examined optimization problem to identify the object’s parameters, i.e., its size and location, by minimizing a structure of discrepancy functional. The quasi-Newton iterative method and the Genetic Algorithm (GA) are used for solving the inverse problem. Case 2 of the study examined the effect of electric voltage on the scattering waves of a buried object in the piezoelectric layer. The procedures of case 1 are administered to case 2 to compare the accuracy of detection results in both cases of the study. A series of practical examples are presented with random noisy data to compare the effect of such loads on the process of detection. The results indicate that using the mechanical load in detecting buried object is clearly accurate compared to voltage load detection.