Structural Health Monitoring Using Ultrasonic Guided-Waves and the Degree of Health Index Cantero Chinchilla, Sergio Chiachío Ruano, Manuel Structural health monitoring Ultrasonic guided-waves Fatigue damage detection Transmission beamforming Degree of health index This paper proposes a new damage index named degree of health (DoH) to efficiently tackle structural damage monitoring in real-time. As a key contribution, the proposed index relies on a pattern matching methodology that measures the time-of-flight mismatch of sequential ultrasonic guided-wave measurements using fuzzy logic fundamentals. The ultrasonic signals are generated using the transmission beamforming technique with a phased-array of piezoelectric transducers. The acquisition is carried out by two phased-arrays to compare the influence of pulse-echo and pitch-catch modes in the damage assessment. The proposed monitoring approach is illustrated in a fatigue test of an aluminum sheet with an initial notch. As an additional novelty, the proposed pattern matching methodology uses the data stemming from the transmission beamforming technique for structural health monitoring. The results demonstrate the efficiency and robustness of the proposed framework in providing a qualitative and quantitative assessment for fatigue crack damage. 2021-03-08T08:19:28Z 2021-03-08T08:19:28Z 2021 journal article Cantero-Chinchilla, S.; Aranguren, G.; Royo, J.M.; Chiachío, M.; Etxaniz, J.; Calvo-Echenique, A. Structural Health Monitoring Using Ultrasonic Guided-Waves and the Degree of Health Index. Sensors 2021, 21, 993. https://doi.org/10.3390/ s21030993 http://hdl.handle.net/10481/66962 10.3390/ s21030993 spa http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España MDPI