TY - JOUR A1 - Zorzi, G. A1 - Baeßler, Matthias A1 - Gabrieli, Fabio T1 - Influence of structural stiffness on ratcheting convection cells of granular soil under cyclic lateral loading N2 - In granular soils, long-term cyclically loaded structures can lead to an accumulation of irreversible strain by forming closed convective cells in the upper layer of the bedding. The size of the convective cell, its formation and grain migration inside this closed volume have been studied with reference to different stiffness of the embedded structure and different maximum force amplitudes applied at the head of the structure. This relation was experimentally investigated by applying a cyclic lateral force to a scaled flexible vertical element embedded in a dry granular soil. The model was monitored with a camera in order to derive the displacement field by means of the PIV technique. Furthermore, the ratcheting convective cell was also simulated with DEM with the aim of extracting some micromechanical information. The main results regarded the different development, shape and size of the convection cell and the surface settlements. T2 - 1st International Conference on the Material Point Method, MPM 2017 CY - Deltares, Delft, The Netherlands DA - 10.01.2017 KW - Particle image velocimetry KW - Cyclic loading KW - Discrete element method KW - Ratcheting convective cell PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-395711 DO - https://doi.org/10.1016/j.proeng.2017.01.046 SN - 1877-7058 IS - 175 SP - 148 EP - 156 PB - Elsevier AN - OPUS4-39571 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - A perspective on research on OWEA substructures considering the authorities approval process N2 - Die BAM unterstützt das Bundesamt für Seeschifffahrt und Hydrografie bei der bautechnischen Bewertung von Tragstrukturen für Offshore-Windparks. Im Hinblick auf die vielfältigen nationalen Aktivitäten in Forschung und Entwicklung wird in der eingeladenen Präsentation auf Schwerpunkte behördlicher Erfahrungen und Bedenken Bezug genommen um eine Perspektive auf zukünftigen Forschungsbedarf zu eröffnen. T2 - 7. Gigawind Symposium CY - Leibniz Universität Hannover, Germany DA - 02.03.2017 KW - OWEA KW - Substructures KW - Authorities approval process PY - 2017 AN - OPUS4-39377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shamsuddoha, Md A1 - Hüsken, Götz A1 - Baeßler, Matthias A1 - Kühne, Hans-Carsten A1 - Thiele, Marc T1 - Critical factors affecting the capacity of cylindrical grouted connections in offshore energy structures N2 - Current trend suggests that global energy consumption will increase in the future. This growing energy demand and advancement of technology lead to explore all potential offshore fossil and non-fossil energy sources, necessitating erection of exploration and production structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with their maintenances. Cylindrical grouted joints provide suitable connections between steel substructure and foundation in these offshore platforms and wind structures especially monopiles for ease of installation. However, these are composite connections with exterior sleeve, interior pile and infill grout. The capacity of these connections is affected by number of factors. The literature over last four decades by numerous researchers has shown the development of these connections with increasingly higher capacities and influences on these capacities due to various factors. This paper provides a comprehensive review on the factors affecting the connection capacity along with technical challenges for the future. Critical aspects and shortcomings of the current connection systems and potential solutions may be sought after for these issues are also discussed. T2 - 36th International Conference on Ocean, Offshore and Arctic Engineering CY - Trondheim, Norway DA - 25.06.2017 KW - Offshore wind energy KW - Grouted connection KW - Joint capacity KW - Shear keys PY - 2017 SN - 978-0-7918-5766-3 DO - https://doi.org/10.1115/OMAE2017-62510 VL - 3B SP - UNSP V03BT02A037, 1 EP - 10 AN - OPUS4-42387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Aktuelle Entwicklungen und Herausforderungen bei Offshore-Gründungen mit Blick auf Forschung und Zulassung N2 - Der Seminarvortrag gibt einen Überblick über den Stand des Ausbaus Offshore Wind, der technischen Fragestellungen für die Tragstrukturen und Gründungen und die zu erwartenden Entwicklungen T2 - Geotechnische Seminarreihe des IBF/KIT CY - Karlsruhe, Germany DA - 23.11.2017 KW - Offshore-Gründungen KW - Windenergie PY - 2017 AN - OPUS4-43130 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kullolli, Borana A1 - Stutz, H. A1 - Bronsert, Jeffrey A1 - Dutto, Paola A1 - Baeßler, Matthias ED - Onate, E. ED - Owen, D. R. J. ED - Peric, D. ED - Chiumenti, M. T1 - A contact problem aplication for the local behaviour of soil pile interaction N2 - The purpose of the work presented in this paper is to analyze locally (at the element level) the contact behavior of a soil-pile contact problem. Therefore, a 2D shear test is modeled using the Finite Element Method. The formulation of a 4 nodded zero-thickness interface element of Beer is chosen with a linear interpolation function. Four constitutive contact models adapted for contact problems have been implemented. The Mohr-Coulomb and Clough and Duncan models were chosen initially, due to the ease of implementation and few number of parameters needed. After, more complicated models in the framework of elasto-plasticity such as: Lashkari and Mortara were implemented for the first time into the finite element code of the shear test problem. They include other phenomena such as: relative density of soil, the stress level and sand dilatancy. From the results the relation between shear displacement and shear stress has been deduced. Finally, a discussion of the advantages and the drawbacks during computation of each model is given at the end. T2 - Conference CY - Barcelona, Spain DA - 05.09.2017 KW - Soil-pile interaction KW - Numerical modelling PY - 2017 SN - 978-84-946909-6-9 SP - 490 EP - 501 PB - CIMNE CY - Barcelona,Spain AN - OPUS4-42960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Untersuchungen zu Tragstrukturen für die Energiewende N2 - Die BAM ist vielfältig mit der Untersuchung von für die Energiewende relevanten Strukturen beschäftigt. Aus dem speziellen Blickwinkel des FB 7.2 werden im Vortrag die Aktivitäten FE, PAZ und BI umfassend für Studenten der BU Weimar dargestellt. T2 - Einblick (#53) CY - Bauhaus Universität Weimar, Germany DA - 19.01.2017 KW - Tragstrukturen KW - Energiewende PY - 2017 AN - OPUS4-39376 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Einführung zum Workshop Groutverbindungen in der Betriebsphase N2 - Mit der Fertigstellung von mehr und mehr Offshore-Windparks rückt die Betriebsphase in den Mittelpunkt des Interesses. Hierbei sind auch die Groutverbindungen, die häufig so konzeptioniert sind, dass wenige Möglichkeiten zur Prüfung und Instandhaltung bestehen, von Interesse. Naturgemäß können auch kaum Erfahrungen für diese Ziele vorliegen. Der geplante Workshop hat folgende Schwerpunkte im Fokus: – Wiederkehrende Prüfung – Instandhaltung und Reparaturkonzepte – Inspektionskonzepte – Zerstörungsfreie Prüfung und – Schadensszenarien – Condition Monitoring Systeme (CMS) Beiträge aus dem Bereich Betrieb, Begutachtung, Forschung, Produktherstellung, Zertifizierung, behördliche Aufsicht und Condition Monitoring sind vorgesehen. Diskutiert werden sollen die technischen Anforderungen an die Überwachung im Betrieb im Hinblick auf die tatsächlich vorhandenen Probleme und Möglichkeiten. Die Präsentation leitet in die Thematik ein. T2 - Workshop Groutverbindung in der Betriebsphase CY - BAM, Berlin, Germany DA - 22.03.2017 KW - Groutverbindung KW - Inspektion KW - WKP KW - Instandhaltung PY - 2017 AN - OPUS4-39495 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Perspektiven für die Forschung an Schienenfahrwegen N2 - Die BAM hat große Kompetenzen und Erfahrungen in der Forschung an Schienenfahrwegen. Aus dem Blick der Abteilung 7 werden Perspektiven aufgezeigt. T2 - 3. Beiratssitzung TF Infrastruktur CY - BAM, Berlin, Germany DA - 06.04.2017 KW - Schienenverkehr PY - 2017 AN - OPUS4-39736 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shamsuddoha, Md A1 - Baeßler, Matthias A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Kühne, Hans-Carsten A1 - Thiele, Marc ED - Banjad Pecur, Ivana ED - Baricevic, Ana ED - Stirmer, Nina ED - Bjegovic, Dubravka T1 - Identification of failure pattern in cylindrical grouted connection for wind structures - a pilot study N2 - At present, Wind Turbine Generators (WTGs) operating in onshore and offshore wind farms are primary sources of renewable energy around the world. Cylindrical grouted sleeve connections are usually adopted in these WTG structures to connect the upper structure and foundation for ease of installation. These structures including grouted connections experience considerable adverse loading during their lifetimes. Settlements were reported inside similar connections used in energy structures especially oil and gas platforms, which were installed in last three decades. Thus, repair and rehabilitation of such connections in existing wind structures should also be planned ahead to keep them operating in the future. The nature of failure and crack generation in grouted connections are crucial prior to adopt a strengthening strategy. This pilot study is carried out to actualize the failure mechanism in the grouted connection, when subjected to axial loading. A novel reusable scaled cylindrical grouted connection with shear keys was designed and tested for its load bearing behaviour. The mechanical test was accompanied by classical measuring techniques (e.g. displacement transducer) as well as non-destructive measuring techniques (e.g. digital image correlation (DIC), acoustic emission analysis (AE)). The failure mechanism incorporating slippage of the shear keys and cracking of the grout was investigated. The capacity and applicability of such test mould were also discussed. The knowledge is expected to pave way towards repair of deteriorated grouted connections with similar geometry and failure pattern. T2 - 1st International Conference on Construction Materials for Sustainable Future (CoMS_2017) CY - Zadar, Croatia DA - 19.04.2017 KW - Grouted connections KW - Cracks KW - Failure KW - Strengthening strategy KW - Digital image correlation KW - Acoustic emission analysis PY - 2017 SN - 978-953-8168-04-8 SP - 544 EP - 551 AN - OPUS4-39914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Structural Health Monitoring – How and to what extent a condition monitoring of the foundation may replace periodical subsea inspections? N2 - Der Betrieb von Offshore-Windenergieanlagen wird zunehmend zum wichtigen Thema im Bereich Windenergie. Anforderungen an Wiederkehrende Prüfungen und den Einsatz von ergänzenden Monitoringsystemen werden in der Präsentation dargestellt und durch Hinweise auf Perspektiven ergänzt. N2 - Operation of Offshore Windfarms has an increasing significance for Wind Energy. Content of the presentation are requirements for inspection and for complementary monitoring. Special focus is on future prospects. T2 - Windforce 2017 CY - Bremerhaven, Germany DA - 09.05.2017 KW - Inspektion KW - Wiederkehrende Prüfung KW - Offshore-Wind KW - Monitoring KW - Inspection KW - Regular inspection KW - Offshore-Wind KW - Monitoring PY - 2017 AN - OPUS4-40256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -