TY - CONF A1 - Heimann, Jan A1 - Mustapha, S. A1 - Yilmaz, Bengisu A1 - Charmi, Amir A1 - Brence, Blaž A1 - Prager, Jens T1 - Untersuchung der Ausbreitung von geführten Ultraschallwellen in Wasserstoffdruckbehältern zur Zustandsüberwachung N2 - Die zunehmende Bedeutung von Wasserstoff als emissionsfreier Energieträger der Zukunft lässt die Anforderungen an eine technisch einwandfreie und sichere Wasserstoffspeicherung steigen. Im Mobilitätssektor kommen dabei vorwiegend Kohlefaserverbundbehälter zur Speicherung von gasförmigem Wasserstoff im Hochdruckbereich zum Einsatz, die sich durch ihre Leichtbauweise bei gleichzeitig hoher Speicherkapazität auszeichnen. Materialfehler oder -ermüdung können jedoch zum Ausfall bis hin zum kritischen Versagensfall führen. Ein sicherer Betrieb der Behälter erfordert daher ein innovatives und zuverlässiges Konzept, um deren Integrität zu gewährleisten und folgenschwere Zwischenfälle zu vermeiden. Die Strukturüberwachung mittels geführter Ultraschallwellen ist dafür einer der prominentesten Ansätze, da sich die Wellen über große Entfernungen in der Struktur ausbreiten können und zudem sehr empfindlich auf kleinste Materialdefekte reagieren. In diesem Beitrag wird der Aufbau eines Sensornetzwerks zur Schadenserkennung und -lokalisierung vorgestellt, das auf den Prinzipien der Ausbreitung geführter Ultraschallwellen in Druckbehältern aus Verbundwerkstoffen basiert. Dazu werden in einem ersten Schritt das dispersive und multimodale Ausbreitungsverhalten analysiert und dominante Wellenmoden identifiziert. Basierend auf der Analyse werden Dämpfungsverhalten und Empfindlichkeit gegenüber künstlichen Defekten bestimmt. Unter Verwendung der ermittelten Informationen wird ein Sensornetzwerk bestehend aus piezoelektrischen Flächenwandlern entworfen, welches den zu untersuchenden Bereich vollständig abdecken soll. Das Ergebnis wird anschließend durch Aufbringen künstlicher Defekte experimentell evaluiert und präsentiert. T2 - DAGA 2023 CY - Hamburg, Germany DA - 06.03.2023 KW - Geführte Ultraschallwellen KW - Zustandsüberwachung KW - Wasserstoffdruckbehälter KW - Sensornetzwerk KW - Structural Health Monitoring PY - 2023 UR - https://pub.dega-akustik.de/DAGA_2023 SN - 978-3-939296-21-8 SP - 1598 EP - 1601 CY - Berlin AN - OPUS4-58022 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mustapha, S. A1 - Yilmaz, Bengisu A1 - Heimann, Jan A1 - Brence, Blaz A1 - Prager, Jens T1 - Guided Waves Propagation in Composite Overwrapped Pressure Vessel N2 - The application of composite overwrapped pressure vessels (COPV) to store hydrogen and other compressed gases, especially when operating at high pressures, imposed the need for an innovative and reliable approach to ensure the safe operation of the system. Continuous structural health monitoring (SHM) based on ultrasonic guided waves (GWs) is a promising approach due to the ability of the wave to propagate for long distances and go around complex structures, moreover the high sensitivity to various failure modes such as delamination, matrix cracking and debonding. In this study, we scrutinize the behavior of (GWs) within the COPV using a network of PZT elements that are used for excitation and sensing. A laser doppler vibrometer (LDV) was also used to scan the surface of the vessel in various directions. L(0,1) and L(0,2) were observed in the captured signal. The L(0, 2) appeared to be a dominant mode in the COPV and was capable of propagating along the entire length and maintaining a good signal-to-noise ratio. The L(0,2) mode maintained the same phase velocity when it is captured at various excitation angles (0, 45, and 90 degrees). The reduced effect of the orthotropy of the materials on the propagating waves is an important result as it will reduce the complexity in data processing when performing damage identification. T2 - 13th. European Conference on Non-Destructive Testing (ECNDT) CY - Lisbon, Portugal DA - 03.07.2023 KW - Composite Overwrapped Pressure Vessels KW - Guided Waves KW - Laser Doppler Vibrometer KW - Structural Health Monitoring KW - Sensors Placement PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-591081 DO - https://doi.org/10.58286/28068 SN - 2941-4989 VL - 1 IS - 1 SP - 1 EP - 6 PB - NDT.net CY - Mayen AN - OPUS4-59108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heimann, Jan A1 - Yilmaz, Bengisu A1 - Charmi, Amir A1 - Duffner, Eric A1 - Schukar, Marcus A1 - Prager, Jens T1 - Structural Health Monitoring (SHM) for continuous monitoring of hydrogen pressure vessels N2 - While hydrogen is one of the most promising energy carriers, the safety of hydrogen storage technology remains one of the most important factors for technological and societal approval. While the engineering safety factors of the pressure vessels are kept high, the periodic inspection and the limited lifetime are making the application very costly considering manpower, time, money, and material waste. The development of an integrated structural health monitoring system can allow an easy transition from the current situation to cost-effective predictive maintenance. Hence, we propose to integrate three different SHM systems into hydrogen pressure vessels, namely guided wave ultrasonics, acoustic emission, and fibre optic sensing, to continuously monitor the condition and integrity. In this work, we evaluated the condition of a Type IV composite overwrapped pressure vessel using ultrasonic guided wave propagation. We mounted fifteen piezo-electric wafers on the composite cylinder by shaping three rings containing five sensors each. We acquired data from the sensor network following different boundary conditions with artificial damages on the selected locations. The data were evaluated with guided wave tomography techniques using ultrasonic features (amplitude, frequency, etc.) as well as artificial intelligence (AI). The results suggest that both traditional guided wave fusion techniques and AI-based characterization methods can detect artificial damages. In future work, it is planned to integrate acoustic emission and fibre optic sensing. Moreover, the measurement and the test results will be implemented into a digital twin to derive trends and make predictions on the damage propagation as well as the remaining useful lifetime. This work has received funding from German Ministry of Economic Affairs and Climate Actions within the QI-Digital initiative (www.qi-digital.de). T2 - SCHALL 23 CY - Wetzlar, Germany DA - 21.03.2023 KW - Structural Health Monitoring KW - Ultrasonic Guided Waves KW - Composite Overwrapped Pressure Vessel KW - Hydrogen PY - 2023 AN - OPUS4-58026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heimann, Jan A1 - Mustapha, Samir A1 - Yilmaz, Bengisu A1 - Prager, Jens T1 - Guided Waves in Composite Overwrapped Pressure Vessels and Considerations for Sensor Placement Toward Structural Health Monitoring—An Experimental Study N2 - The utilization of composite overwrapped pressure vessels (COPVs) to store hydrogen, especially at high pressures, is gaining more popularity due to their lightweight design and high storage density, offering significant economic advantages. However, the presence of material defects or fatigue can lead to critical failures, requiring an innovative and robust approach to ensure safe operation and system integrity. Developing a continuous structural health monitoring (SHM) system for COPVs can provide comprehensive realtime information about their condition, facilitating a shift away from periodic inspections. This study scrutinizes the behavior of guided waves (GWs) within COPVs to design a sensor ,network for damage detection and localization. First, the dispersive and multimodal propagation behavior of GWs is experimentally investigated. Subsequently, important parameters for the network design are derived and finally a sensor network consisting of 15 piezoelectric transducers is designed to cover the entire cylindrical area. The effectiveness is then evaluated experimentally by placing artificial defects on the surface of the COPV. The multi-layered dataset of GW signals was analyzed using both commonly used ultrasonic features (e.g., amplitude, frequency, time of flight) as well as statistical features (kurtosis, skewness, variance, etc.). These features were utilized to compute a damage index, and the effectiveness of the detection performance was assessed using receiver operating characteristic curves. It can be seen that some features are more sensitive and robust under varying experimental conditions. The results show that ultrasonic GW SHM system is a promising solution for damage detection and localization in COPVs. KW - Composite Overwrapped Pressure Vessels KW - Guided Waves KW - Structural Health Monitoring KW - Sensors Placement KW - Damage Detection KW - Damage Localization KW - Elastic Wave KW - Testing Methodologies KW - Ultrasonics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625239 DO - https://doi.org/10.1115/1.4067667 SN - 2572-3898 VL - 8 IS - 3 SP - 031007-1 EP - 031007-13 PB - The American Society of Mechanical Engineers (ASME) CY - New York, USA AN - OPUS4-62523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -