Most of the existing Structural Health Monitoring (SHM) systems are vulnerable to environmental and operational damages. The majority of these systems cannot detect the size and location of the damage. Guided wave techniques are widely used to detect damage in structures due to its sensitivity to different changes in the structure. Finding a mathematical model for such system will help to implement a reliable and efficient low-cost SHM system. In this paper, a mathematical model is proposed to detect the size and location of damages in physical structures using the piezoelectric sensor. The proposed model combines both pitch-catch and pulse-echo techniques and has been verified throughout simulations using ABAQUS/ Explicit finite element software. For empirical verification, data was collected from an experimental set-up using an Aluminum sheets. Since the experimental data contains a lot of noises, a Butterworth filter was used to clean up the signal. The proposed mathematical model along with the Butterworth filter have been validated throughout real test bed.
