Numerical study of nonlinear interaction of the guided wave due to breathing type debonding in stiffened panel

The common tool for assessment of breathing-type debonding in metallic or composite structures is nonlinear guided wave-based technique. The past studies show that with debonding size, the strength of the nonlinearity does not exhibit strictly increasing or decreasing trends, or that the monocity is valid up to a certain size limit of debonding. This paper presents the study of non-linear interaction of guided waves in the debonding interface of a metallic stiffened panel. The study attempts to establish a relationship between the contact energy generated by the contact acoustic nonlinearity (CAN) at the debonding interface and the associated nonlinearity strength for various debonding sizes at various excitation frequencies. A numerical model of the stiffened panels is developed in three-dimensional finite element (FE) and validated with experiments for the study of interaction of nonlinear guided waves. The validated FE model is used to conduct studies on nonlinear interactions in debonding. The outcome of this study contributes to a better understanding of how guided waves can be used to effectively assess the debonding in metallic stiffened panels by considering non-linear interactions at the debonding interface. The study also provides insights into a more accurate and consistent quantification of the debonding using higher harmonic signals and contact energy produced by non-linear interactions.