Lamb wave-based baseline-free damage localization in pipes with surface-mounted piezo patches

This study presents a baseline-free damage localization technique for pipelines by extending a recently developed virtual refined time-reversal method (VRTRM) based on Lamb waves while employing the reconstruction algorithm for probabilistic inspection of defects (RAPID) for damage imaging. A network of piezoelectric patch transducers surface-bonded to the pipe is deployed for detecting damage without requiring prior baseline data. The proposed approach is first established through finite element simulations of guided wave propagation in a metallic pipe and then experimentally demonstrated on a pipeline under various damage scenarios: single, dual, and multiple defects. Results indicate that applying VRTRM at the best reconstruction frequency–specific to the sensor network-adhesive-pipe system– yields highly accurate damage localization. In contrast, the conventional time-reversal method using arbitrarily selected frequencies results in poor or inaccurate predictions. The proposed method offers a highly promising baseline-free solution for damage localization in pipeline structures with built-in transducers.