Structural Health Monitoring of Metallic Tubes inducing Guided Electromagnetic Waves

Guided electromagnetic wave (GEMW) propagation using ultra-wideband signals is a novel approach for damage detection. Wave transmission and reflection can be used to warn the presence of such a defect within the waveguides. The present work proposes a feasibility analysis for a structural health monitoring system employing permanently integrated GEMW sensors. This concept allows to interrogate the structure continuously using transmitters and receivers when the electromagnetic waveguide is established. To this end, a metallic tube is equipped with a microwave broadband attached to the structures' surface. To validate the detectability of damage, a reversible defect is modeled through removable bolts accessible from one side of the surface of the cylinder. The experiments are carried out considering different damage severity and keeping constant the environmental scenario. The characteristic changes of GEMW signals are adopted in a damage index approach employed to show that defect can be detected sensitively.