TY - CONF A1 - Kästle, Emanuel D. T1 - Failure monitoring and classification from acoustic emission tests on impact-damaged hydrogen composite pressure vessels N2 - Composite overwrapped pressure vessels (COPV) for hydrogen will play an important role in emission free mobility and energy storage. The DELFIN project (2018 – 2022) was set up with the goal of developing improved COPVs that are lighter, cheaper and more durable. A key aspect of this project was to conduct full-scale impact tests with different gas pressure levels that were used to evaluate the vessels’ crash performance and to verify numerical impact simulations. These tests were followed by controlled pressure experiments until the burst pressure was reached. The procedure was monitored with acoustic emission testing (AT) and subsequent computer tomography (CT). The residual COPV stability and the AT results are compared to different scenarios regarding the impact energies and impact angles. The event localization from AT shows a clear correlation of the emitted energy with the damaged areas. We classify the recorded signals into groups that can be related to the failure mechanism and compare those to the pressure evolution before failure of the COPV. All tests indicate that large impact energies lead to a significant reduction of the burst pressure of COPVs, whereas a higher internal pressure can have a stabilizing effect that reduces the damaging effect. T2 - EWGA2024 36th Conference of the European Working Group on Acoustic Emission, 18-20 September 2024, Potsdam, Germany CY - Potsdam, Germany DA - 18.09.2024 KW - Acoustic Emission KW - Carbon-Fibre Overwrapped Pressure Vessels KW - Impact Damage KW - Cluster Analysis KW - Frequency Features PY - 2024 AN - OPUS4-61674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kästle, Emanuel D. A1 - Ghaznavi, Ali A1 - Duffner, Eric T1 - Failure monitoring and classification from acoustic emission tests on impact-damaged hydrogen composite pressure vessels N2 - A total of nine heavily damaged carbon-fibre overwrapped pressure vessels are tested. The burst pressure of the damaged vessels correlates with the impact energy and the internal pressure during impact. No internal pressure leads to larger deformation and lower burst pressure. The vessels are tested with acoustic emissions prior to bursting. It can be shown that major instabilities give rise to a significantly increased number of acoustic signals. The location of occurrence corresponds to the impact regions. The signals are studied in terms of their frequency content and it can be shown that high frequency signals experience strong damping so that there are only few recorded high-frequency events and even fewer that are locatable. The data is further used in a cluster analysis to assign the signals to different failure types. With the given experimental design, no clear patterns emerge so that the failure association remains ambiguous. KW - Acoustic Emission KW - Carbon-Fibre Overwrapped Pressure Vessels KW - Impact Damage KW - Cluster Analysis KW - Frequency Features PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613266 DO - https://doi.org/10.58286/30256 SN - 1435-4934 VL - 29 IS - 10 SP - 1 EP - 12 PB - NDT.net GmbH & Co. KG AN - OPUS4-61326 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Duffner, Eric A1 - Kästle, Emanuel D. T1 - Acoustic Emission Testing of COPV’s Current Work in DAVID Project N2 - Acoustic Emission Testing is a promising approach to better understand and monitor damage progression in composite pressure vessels and to predict failure. The presentation shows some of the ongoing work at the BAM within the DAVID project. T2 - DGZfP Tagung Fachausschuss Schallemission Herbst 2024 CY - Berlin, Germany DA - 08.10.2024 KW - Acoustic Emission KW - Carbon-Fibre Overwrapped Pressure Vessels KW - Impact Damage KW - Cluster Analysis KW - Frequency Features PY - 2024 AN - OPUS4-61678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -