Monitoring the Progression of a Cylindrical Flaw in a Reinforced Aluminum Panel Using Piezopolymer Interdigitated Lamb Wave Transducers

Defect detection and progression monitoring are important in SHM for aerospace structures. Piezopolymer interdigital transducers (IDTs) have been demonstrated to be efficient to cover distances up to 70 cm on aluminum plates when the mode selection and the electrode pattern is optimized by using FEM. In this work we investigated the detectability of a cylindrical defect (depth 2.5 mm) in an aluminum panel with thickness of 5 mm, typically used in cislunar habitat modules. The diameter of the defect is increased from 5 to 10 mm in a 5mm thick reinforced aluminum panel. The objective is to determine the defect detectability by a layout of IDT at distance up to 35 cm to minimize the number of IDTs to be installed on the target structure.