TY - CONF A1 - Cuéllar, Pablo T1 - Deep foundations for offshore wind turbines - 2nd part: lateral behavior & advanced topics T1 - Cimentaciones profundas para aerogeneradores marinos. 2a parte: Comportamiento Lateral + Temática avanzada N2 - This presentation deals with the phenomenology and design of pile foundations for offshore wind turbines, and is divided into two lectures. The second lecture continues with the case of laterally loaded offshore piles, which bears most relevance for the case of the monopile foundations. Here again, a clear separation between physical reality and design methods is intended. Finally, the last part of the second lecture introduces several advanced topics which lie outside the classical design approaches, namely the hydromechanical coupling effects (i.e. the excess pore-pressure generation around the monopiles), the cyclic pile fatigue and the so-called pile setup (i.e. the time effects on the axial pile capacity). The relevance of the latter two topics is illustrated with experimental results from a field testing campaign on real large-scale piles. T2 - Masters course on Soil Mechanics and Geotechnical Engineering. Geotechnical Laboratory of CEDEX CY - Online meeting DA - 17.03.2023 KW - Pile foundations KW - Offshore wind turbines KW - Physical phenomenology KW - Design methods KW - Numerical modelling KW - Physical testing PY - 2023 AN - OPUS4-57178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Balscheit, Hagen A1 - Cuéllar, Pablo A1 - Geißler, Peter A1 - Thiele, Marc A1 - Schepers, Winfried A1 - Fontoura Barroso, Daniel T1 - Large Monopiles: Experimental and numerical investigation of monopile tip buckling during installation as well as of local pile buckling under operational conditions N2 - The research project Verification of Buckling Assessment and Behaviour in Large Monopiles (VERBATIM) focuses on challenges arising due to the ongoing increase of dimensions of monopiles as foundation for offshore wind turbines. This project is focused on two main topics: - Monopile tip buckling during pile installation - Local buckling of embedded piles during operation It is known from previous investigations and experiences in practice that large deformations of a monopile tip during offshore installation works can occur. These large deformations initiated at the tip of the monopile are commonly referred to as “pile tip buckling”. Own research focuses on optimising monopile dimensions to reduce the cost of monopile foundations for offshore wind turbines while preventing pile tip buckling. Buckling of embedded cylindrical shells for offshore structures is a common engineering task. Structures can be analysed using standard software and have been done so in recent studies e.g., Gottschalk. However, the trend towards larger monopile and optimised structures has led to a fundamental need for better and verified models. A main challenge is the submodelling of the structure-soil-interaction. Developing such complex models is one main goal of the VERBATIM project. For both main topics model tests were performed at the laboratories of BAM and TU Berlin. These experimental results were used to verify related numerical models and simulations. T2 - WindEurope CY - Copenhagen, Denmark DA - 25.04.2023 KW - Monopiles KW - Tip Buckling KW - Pile Buckling KW - Foundations KW - Offshore KW - Windenergy PY - 2023 AN - OPUS4-57405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Balscheit, Hagen T1 - Offshore Gründungen - Nichtlineare Effekte bei der stahlbaulichen Auslegung großer Pfahlgründungen für Offshore Windenergieanlagen N2 - Dieser Kurzvortragg erläutert nichtlineare Phänomene die angesichts der aktuell wachsenden Dimensionen von Monopfahlgründungen für Offshorewindenergieanlagen zunehmend an Bedeutung gewinnen. Insbesondere wird dabei auf das Pfahlfußbeulen sowie das Schalenbeulen des bereits installierten Pfahles eingegangen. T2 - 27. Brandburgischer Bauingeniertag BBIT2023 CY - Cottbus, Germany DA - 09.06.2023 KW - Beulen KW - Pfahlfußbeulen KW - Stabilität KW - Monopile KW - Windenergie PY - 2023 AN - OPUS4-57653 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Stolpe, Heiko A1 - Wiehle, Philipp T1 - Moisture diffusion affected by the Knudsen effect in temporal changing pore networks N2 - Almost all building materials in civil engineering have an open porosity and interact with or are affected by the environmental conditions. Structures might suffer from effects such as moisture adsorption, carbonation, corrosion, penetration of salt ions and chemical substances, etc. In the hygroscopic range, these processes are mostly driven by diffusion. Due to the confinement of small pores (< 1 µm), the Knudsen effect reduces the molecular diffusion. This reduction can become more significant in case of temporal changing pore systems because of physisorption of water vapor, carbonation, or chemisorption. In this study, unstabilised earth blocks and earth masonry are investigated. In a first step, the pore size distribution of the blocks is measured and sorption isotherms are recorded in experiments. Besides the ordinary physisorption, the involved clay minerals undergo swelling or shrinking due to chemisorption. The following two effects must be considered: first, the reduction of the available pore space by the adsorbed water layer. For this, the Hillerborg sorption theory is used, which is a combination of the well-known Brunauer-Emmett-Teller sorption theory and the Kelvin equation. This allows the computation of adsorbed water layers even in curved pore geometries. Second, the variation of the initial pore size distribution due to chemisorption needs to be modelled. Based on these two models, the effective diffusion coefficient can be predicted. For validation, arrays of relative humidity sensors were embedded into a free-standing earth masonry wall. This monitoring was carried out over more than a year to have a broad variety of environmental conditions and was located in Berlin, Germany. The prediction of the effective diffusion coefficient can also be transferred to other processes and allows the investigation of materials having temporarily changing pore systems. Examples are the carbonation of cementitious materials, alkali silica reaction, calcium leaching of long-lasting structures, etc. This effect becomes most prominent in the meso-pore range and might alter the effective diffusion coefficient by more than 100 %. T2 - 4th International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 08.03.2023 KW - Earth masonry KW - Material moisture KW - Molecular diffusion KW - Chemisoprtion KW - Knudsen effect KW - Physisorption PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571391 SP - 1 EP - 8 PB - RILEM CY - Champs-sur-Marne AN - OPUS4-57139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Stolpe, Heiko A1 - Wiehle, Philipp T1 - Moisture diffusion affected by the Knudsen effect in temporal changing pore networks N2 - Almost all building materials in civil engineering have an open porosity and interact with or are affected by the environmental conditions. Structures might suffer from effects such as moisture adsorption, carbonation, corrosion, penetration of salt ions and chemical substances, etc. In the hygroscopic range, these processes are mostly driven by diffusion. Due to the confinement of small pores ( 1 m), the Knudsen effect reduces the molecular diffusion. This reduction can become more significant in case of temporal changing pore systems because of physisorption of water vapor, carbonation, or chemisorption. In this study, unstabilised earth blocks and earth masonry are investigated. In a first step, the pore size distribution of the blocks is measured and sorption isotherms are recorded in experiments. Besides the ordinary physisorption, the involved clay minerals undergo swelling or shrinking due to chemisorption. The following two effects must be considered: first, the reduction of the available pore space by the adsorbed water layer. For this, the Hillerborg sorption theory is used, which is a combination of the well-known Brunauer-Emmett-Teller sorption theory and the Kelvin equation. This allows the computation of adsorbed water layers even in curved pore geometries. Second, the variation of the initial pore size distribution due to chemisorption needs to be modelled. Based on these two models, the effective diffusion coefficient can be predicted. For validation, arrays of relative humidity sensors were embedded into a free-standing earth masonry wall. This monitoring was carried out over more than a year to have a broad variety of environmental conditions and was located in Berlin, Germany. The prediction of the effective diffusion coefficient can also be transferred to other processes and allows the investigation of materials having temporarily changing pore systems. Examples are the carbonation of cementitious materials, alkali silica reaction, calcium leaching of long-lasting structures, etc. This effect becomes most prominent in the meso-pore range and might alter the effective diffusion coefficient by more than 100 %. T2 - 4th International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 08.03.2023 KW - Earth masonry KW - Material moisture KW - Molecular diffusion KW - Chemisoprtion KW - Knudsen effect KW - Physisorption PY - 2023 AN - OPUS4-57140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichner, Lukas T1 - Design of offshore jacket support structure for experimental fatigue life evaluation N2 - One crucial metric of interest to wind farm operators is the remaining useful life (RUL) of single components, wind turbines, or even entire wind farms. Occasionally, questions arise regarding how to operate a turbine, even in the presence of manufacturing or design errors, which from a computational design standpoint reduce the remaining lifetime below the intended service life. A typical measure involves adapting the monitoring and inspection plan. Using such a maintenance plan, the author intends to simulate the lifetime of jacket-type structure in a fatigue test. The objective of the experiment is to demostrate that systems like three-dimensional jackets possess redundancies that enable reliable continued operation, despite the reduced fatigue life of individual components due to technical flaws, if an appropriate maintenance concept is in place. This presentation discusses the steps leading to the procedure of the experiment including the design process and the maintenance planning. T2 - 19th eawe PhD Seminar CY - Hannover, Germany DA - 06.09.2023 KW - Offshore wind energy KW - Jacket support structure KW - Simulation and experiment KW - Structural integrity management KW - Risk-based maintenance planning PY - 2023 AN - OPUS4-58240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerards-Wünsche, Paul A1 - Ratkovac, Mirjana A1 - Schneider, Ronald A1 - Hille, Falk A1 - Baeßler, Matthias T1 - A framework for assessing the reliability of crack luminescence – an automated fatigue crack detection system N2 - The new crack luminescence method offers the possibility of making fatigue surface cracks in metallic materials more visible during inspections through a special coating system. This coating system consists of two layers, whereby the first layer has fluorescent properties and emits visible light as soon as it is irradiated by UV light. The top layer is black and is designed to prevent the fluorescent layer from emitting if no crack develops in the underlying material. The technique proved particularly useful in a wide variety of fatigue tests of steel components under laboratory conditions. Moreover, it has the potential to be used in various industrial applications. To enable industrial deployment and integration into maintenance strategies, a concept study is developed in this contribution, resulting in a qualification framework that can serve as a foundation for determining the reliability of the crack luminescence system in terms of a probability of detection curve. Within this study, factors causing measurement variability and uncertainty are being determined and their influences assessed. Due to the extension of the system by a moving computer vision system for automated crack detection using artificial intelligence, additional long-term effects associated with structural health monitoring systems need to be incorporated into an extended probability of detection study as part of the technical justification. Finally, important aspects and findings related to design of experiments are discussed, and a framework for reliability assessment of a new optical crack monitoring method is presented, emphasizing the influence of various uncertainty parameters, including long-term effects such as system ageing. T2 - SPIE Conference Smart Structures + Nondestructive Evaluation 2023 CY - Long Beach, CA, USA DA - 24.03.2023 KW - Structural Health Monitoring KW - Non-Destructive Evaluation KW - Probability of Detection KW - Reliability KW - Artificial Intelligence KW - Computer Vision KW - Crack Luminescence PY - 2023 AN - OPUS4-57245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Schneider, Ronald T1 - OWEC repowering from a structural engineering and research perspective N2 - A significant number of new wind farms has to be installed and, at the same time, existing wind farms reaching the end of their planned life need to be reused efficiently to ensure that the ambitous goals for deploying offshore wind are met. Some relevant reuse alternatives for offshore wind farms are lifetime extension, repowering utilizing existing substructures and full replacement. In this presentation - starting from experience gained from extending the lifetime of the of the U1 metro viaduct in Berlin - we discuss end-of-life decision making in offshore wind. We focus particularly on issues concerning substructures and highlight existing challenges and opprtunities in research and development. T2 - RWE RePowering Event CY - Wilhelmshaven, Germany DA - 10.10.2023 KW - Offshore wind KW - End-of-life decision making KW - Repowering KW - Substructures PY - 2023 AN - OPUS4-58632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Structural integrity management research at BAM N2 - This presentation provides an overview on the structural integrity management research at BAM. In addition, a framework for monitoring and risk-informed inspection and maintenance planning for offshore steel structures is presented. T2 - Structural Health Monitoring Using Statistical Pattern Recognition CY - Berlin, Germany DA - 20.03.2023 KW - Structural integrity KW - Monitoring KW - Maintenance KW - Inspeciton KW - Bridges KW - Offshore wind PY - 2023 AN - OPUS4-57864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lesny, K. A1 - Arnold, P. A1 - Sorgatz, J. A1 - Schneider, Ronald T1 - Wie sicher sind unsere Bauwerke? - Strukturpapier des Arbeitskreises 2.15 der DGGT „Zuverlässigkeitsbasierte Methoden in der Geotechnik“ N2 - Der zukünftige Eurocode 7 wird ausdrücklich die Nutzung zuverlässigkeitsbasierter Methoden in der geotechnischen Planung und Bemessung erlauben. In Deutschland gibt es bisher kaum Erfahrung in der praktischen Anwendung derartiger Verfahren und entsprechend sind die Vorbehalte gegenüber diesen Methoden oft groß. Der neue DGGT-Arbeitskreis (AK) 2.15 „Zuverlässigkeitsbasierte Methoden in der Geotechnik“ hat sich zum Ziel gesetzt, durch praxisorientierte Anleitungen und Empfehlungen sowie begleitende Aus- und Weiterbildungsangebote den praktischen Zugang zu diesen Verfahren zu unterstützen. Ziel ist es, Möglichkeiten und Grenzen zu verdeutlichen sowie vor allem ihre Potenziale zu erschließen. In dem vorliegenden Beitrag werden allgemeine Grundlagen und die zukünftigen Arbeitsfelder des AK 2.15 vorgestellt. Ausgehend von der Einführung relevanter Fachbegriffe wird zunächst die Einbettung zuverlässigkeitsbasierter Verfahren in den aktuellen Normungs- und Regelungskontext aufgezeigt. Anschließend werden anhand des Lebenszyklus eines geotechnischen Bauwerks die Unsicherheiten in den geotechnischen Prognosen und Bewertungen beschrieben. Daran anknüpfend wird aufgezeigt, an welchen Stellen zuverlässigkeitsbasierte Methoden als mögliches Werkzeug sinnvoll genutzt werden können, um Ingenieur:innen, Bauherr:innen und Prüfer:innen in Nachweis- und Entscheidungsprozessen zu unterstützen. Zu den sich daraus ableitenden Arbeitsthemen werden durch den AK 2.15 zukünftig Empfehlungen erarbeitet und sukzessive veröffentlicht KW - Brückensicherheit KW - Sicherheit KW - Wahrscheinlichkeit KW - Zuverlässigkeit KW - Bemessung KW - Bewertung KW - Offshore Wind PY - 2023 DO - https://doi.org/10.1002/gete.202300014 VL - 46 IS - 3 SP - 153 EP - 164 PB - Ernst & Sohn GmbH CY - Berlin AN - OPUS4-58208 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -