TY - CONF A1 - Benseghier, Z. A1 - Cuéllar, Pablo A1 - Luu, L.-H. A1 - Bonelli, S. A1 - Philippe, P. T1 - Parallel LBM-DEM simulation of fluid flow erosion using GPU N2 - Surface erosion of a cohesive granular soil by a fluid flow is investigated numerically by coupling the Lattice Boltzmann Method (LBM) for the fluid phase and the Discrete Element Method (DEM) for describing the motion of the solid particles. In addition, inter-particles cohesion is insured by a contact model featuring a paraboloidal yield surface. The use of a fully resolved LBM-DEM coupling technique is currently limited due to the computational cost when simulating a large number of particles. This issue can be overcome using the graphics processing unit (GPU) thanks to ist massively parallel hardware architecture. Here, we first present a 2D GPU implementation of LBM-DEM coupling for a granular assembly. The GPU implementations are approximatively 30 times faster than a single core CPU version. Then, we apply the parallelization technique to practical erosional cases, namely the jet erosion test (JET) and the shear-driven erosion by a Couette flow. These numerical tests aim to relate micro parameters of a cohesive material (eg. cohesion) to macro parameters (eg. soil erodibility, mechanical strengths). Preliminary results show that micromechanical features indeed provide a novel insight of soil erosion phenomena. T2 - CILAMCE 2018 CONGRESS CY - Paris/Compiègne, France DA - 11.11.2018 KW - Micromechanical LBM-DEM simulation KW - GPU parallelisation KW - Soil erosion PY - 2018 AN - OPUS4-46594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Benseghier, Z. A1 - Cuéllar, Pablo A1 - Luu, L.-H. A1 - Delenne, J.-Y. A1 - Bonelli, S. A1 - Philippe, P. T1 - Use of DEM-LBM modeling to prove the relevance of free jet model for soil erosion by impinging jet N2 - The aim of this study is to provide a micromechanical insight into the mechanisms taking place during the erosion of a cohesive granular material driven by a fluid flow, the objectives are summarized as follows: Perform numerical erosion tests. Parallelization of the code (Gpu). Extensive parametric analysis => rely micro parameters (eg. Cohesion) to macro parameters (eg. Soil erodibility, mechanical strengths). T2 - 2nd YADE Workshop, IRSTEA, Aix-en-Provence CY - Aix-en-Provence, France DA - 26.04.2018 KW - DEM-LBM simulation KW - Erosion of cohesive soils KW - Jet erosion test PY - 2018 AN - OPUS4-46315 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Costard, René A1 - Agasty, Amit A1 - Hering, Marcus A1 - Hüsken, Götz A1 - Hicke, Konstantin T1 - Auswirkungsbetrachtungen auf Strukturen T1 - Scaling of Blast Effects on Reinforced Concrete Structures N2 - Protection against terroristic or accidental scenarios in industrial settings requires suitable designs of structures to resist blast loads. Field testing as well as finite element simulations are among the techniques available to engineers in the understanding of the structural behavior against blast loading. As blast testing of complex scenarios can be very resource intensive, tests are generally performed for simplified scenarios. Numerical tools can be used to model these scenarios to get better insight into blast loading, structural response, and the resulting damage to the structure. During the next steps, the simplified scenario is successively modified in numerical simulations to incorporate complexities that cannot be covered in blast testing experiments. One of the conditions for this approach to work is that the original simplified numerical simulation is valid. The scopes and challenges encountered in such a validation are the focus of this presentation/article. A relatively ‘simple’ field test of a horizontal reinforced concrete (RC) slab subjected to blast loading is taken as an example for validation of the performance of numerical tools. The blast test incorporated various measurement techniques to quantify the blast load as well as the behavior of the RC slab. Blast load was measured using flush mounted piezoelectric pressure gauges, whereas acceleration sensors and fiber-optic sensor cables were used to characterize the dynamic behavior of the slab under blast loading. Additionally, damage characteristics were ascertained also using fiber optic sensing. The application of such measurement techniques, along with different numerical software available for the analysis of the scenario in question, demonstrate the scope of our contribution. When it comes to the challenges, it begins with proper instrumentation of the test specimen followed by the data processing. For numerical modelling, geometric conditions with appropriate boundary constraints, physical conditions such as the configuration of the rebars, as well as material parameters add to this challenge. The issues of choosing appropriate material models and comparison of results with multiple software tools will be discussed. This discussion forms the basis for a coherent approach to technical-safety assessment of blast effects on structures in its broader sense. T2 - Beiratssitzung Infrastruktur CY - Berlin, Germany DA - 11.04.2024 KW - Blast KW - Scaling KW - Fiber optic sensing KW - CFD KW - FEM PY - 2024 AN - OPUS4-59849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Deep foundations for offshore wind turbines - 1st part: axial behavior T1 - Cimentaciones profundas para aerogeneradores marinos. 1a parte: Comportamiento axial N2 - This presentation deals with the phenomenology and design of pile foundations for offshore wind turbines, and is divided into two lectures. The first lecture presents a brief introduction to the context and peculiarities of such foundations, and then focuses on the particular case of axially loaded piles. This part is most relevant for the relatively slender piles of the multi-pile substructures (i.e. jackets and tripods). A clear distinction between physical phenomenology and practical design is drawn here. 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 - OPUS4-57176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo A1 - Baeßler, Matthias T1 - Design challenges for offshore wind-farms. From foundation mechanics to wind-farm aerodynamics N2 - This talk provides a brief introduction on general engineering aspects of offshore wind energy production. Then some geomechanical issues for the foundation of OWTs into the seabed are introduced, while the results from experimental investigations and coupled computational analysis are discussed. In the second part of the seminar, the hydromechanical Wave–Tower interaction is firstly discussed. Then, some general aspects of the windfarm aerodynamics are introduced. On the one hand, some modelling possibilities for the wake analysis of single turbines and turbine groups are discussed. And on the other hand the relevance of such analyses for a proper windfarm layout optimization is pointed out. Concerning the geomechanical issues the talk shows that: i) The pile’s bearing capacity can degrade under cyclic loading (waves, wind, …). ii) The time effects can be relevant: Capacity improvement can be substantial, but also fragile. iii) There are cyclic PWP effects: Cyclic interaction with pore water may lead to soil softening and an uncoupled analysis (current design practice) is potentially unsafe. And concerning the hydromechanical and aerodynamical design considerations, this seminar shows that: i) Numerical analysis of turbine’s interaction with wind/waves is useful and affordable. ii) Simplified models can provide insight into windfarm aerodynamics. iii) Turbulent wake analysis is very relevant for the windfarm layout. T2 - Energy Science Kolloquium CY - Fakultät für Physik, Universität Duisburg-Essen, Germany DA - 25.01.2018 KW - Offshore wind farms KW - Geomechanics KW - Design PY - 2018 AN - OPUS4-43958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Deep foundations for offshore wind turbines T1 - Cimentaciones profundas para aerogeneradores marinos N2 - This presentation deals with the phenomenology and design of pile foundations for offshore wind turbines, and is divided in two lectures. The first lecture presents a brief introduction to the context and peculiarities of such foundations, and then focuses on the particular case of axially loaded piles. This part is most relevant for the relatively slender piles of the multi-pile substructures (i.e. jackets and tripods). A clear distinction between physical phenomenology and practical design is drawn here. The second lecture continues with the case of lateraly 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 cyclic pile fatigue and the so-called pile setup (i.e. the time effects on the axial pile capacity). The relevance of these 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 2018, Geotechnical Laboratory of CEDEX CY - Madrid, Spain DA - 13.04.2018 KW - Pile foundations KW - Offshore wind energy KW - Physical phenomenology KW - Design practice PY - 2018 AN - OPUS4-44764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Deep foundations for offshore wind turbines. Lecture 1: Axial behaviour T1 - Cimentaciones profundas para aerogeneradores marinos - Parte 1: Comportamiento axial N2 - This presentation deals with the phenomenology and design of pile foundations for offshore wind turbines, and is divided into two lectures. The first lecture presents a brief introduction to the context and peculiarities of such foundations, and then focuses on the particular case of axially loaded piles. This part is most relevant for the relatively slender piles of the multi-pile substructures (i.e. jackets and tripods). A clear distinction between physical phenomenology and practical design is drawn here. T2 - Masters course on Soil Mechanics and Geotechnical Engineering. Geotechnical Laboratory of CEDEX CY - Online meeting DA - 21.04.2020 KW - Pile foundations KW - Offshore wind turbines KW - Physical phenomenology KW - Design methods PY - 2020 AN - OPUS4-51057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Deep foundations for offshore wind turbines. Lecture 2: lateral behaviour and advanced topics T1 - Cimentaciones profundas para aerogeneradores marinos - Parte 2: Comportamiento lateral y tematica 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 lateraly 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 - 21.04.2020 KW - Pile foundations KW - Offshore wind turbines KW - Physical phenomenology KW - Design methods PY - 2020 AN - OPUS4-51059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Erosion and soil mechanics for civil constructions. Applications and opportunities of micromechanical modelling N2 - This presentation provides an overview on general issues related to erosive failures in civil constructions like hydraulic infrastructures and offshore foundations. A brief introduction to the related research activities of BAM in the field of offshore wind energy is first provided, and the general possibilities for micromechanical modelling approaches are outlined. Finally, the ongoing DFG-ANR research project COMET is introduced. T2 - Vortrag am Lehrstuhl "System simulation" an der FAU CY - Friedrich–Alexander University, Erlangen, Germany DA - 16.10.2019 KW - Micromechanical analysis KW - Offshore wind energy foundations KW - Erosion KW - Earthen hydraulic infrastructures PY - 2019 AN - OPUS4-49311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Wind energy challenges. An offshore perspective and some possible solutions N2 - This talk provides a brief introduction on general engineering challenges for the offshore (marine) wind energy production, focusing on material, structural and hydromechanical aspects. The talk begins with a broad overview on general trends for offshore wind-farms, with insights on some characteristic structural features and their associated loads. Then, some particular open issues for the foundation of the offshore wind turbines into the seabed are introduced. Here, different research approaches are discussed, from experimental investigations to coupled computational analysis at micro- and macroscopic scales. In the second part of the seminar, both the hydromechanical Wave–Tower interaction and some general aspects of the windfarm aerodynamics (wake analysis) are discussed. Some modelling possibilities in the frame of CFD (computational fluid dynamics) are introduced and the relevance of such analyses for a proper windfarm layout optimization is pointed out. Summing up, this seminar aims to show that: i) Numerical analysis of the turbine’s interaction with wind/waves and with the seabed is both useful and affordable. ii) Simplified models can provide an insight into windfarm aerodynamics. iii) Turbulent wake analysis is very relevant for the windfarm layout. T2 - Bad Honnef Physics School „Energy Science – an interdisciplinary challenge“ CY - Physikzentrum Bad Honnef, Bad Honnef, Germany DA - 01.09.2019 KW - Offshore wind energy KW - Mechanical challenges KW - Offshore foundations KW - Soil-water-structure interaction PY - 2019 AN - OPUS4-48873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -