TY - GEN A1 - Andrés Arcones, Daniel A1 - Diercks, Philipp A1 - Robens-Radermacher, Annika A1 - Rosenbusch, Sjard Mathis A1 - Tamsen, Erik A1 - Tyagi, Divyansh A1 - Unger, Jörg F. T1 - FenicsXConcrete N2 - FenicsXConcrete is a Python package for the simulation of mechanical problems. The general PDE solving software FEniCSx is extended with classes describing experimental setups, mechanical problems, thermo-mechanical problems, additive manufacturing and sensors. KW - FEM KW - Fenics KW - Concrete modelling PY - 2023 UR - https://github.com/BAMresearch/FenicsXConcrete DO - https://doi.org/10.5281/zenodo.7780757 PB - Zenodo CY - Geneva AN - OPUS4-59121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosenbusch, Sjard Mathis T1 - Gradient-enhanced models in blast simulations of concrete structures N2 - Blast experiments on reinforced concrete structures are often limited to small structures and therefore simple shock waves. Such experiments are carried out at the Bundesanstalt für Materialforschung und -prüfung (BAM) and the structural response is investigated using several measuring methods. Complex load scenarios that occur as a result of reflection of the shock wave in larger structures are harder to realize in practice. Numerical simulations for the propagation of the shock wave and the structural response can therefore be an alternative method for the investigation of blast loads on complex structures. For the simulation of concrete under impact and blast loads, several local constitutive models exist that are formulated as plasticity models with softening taken into account by introducing a scalar damage field. Local damage models however often lead to mesh-dependent results which do not converge with mesh refinement. In order to achieve meaningful predictions from numerical experiments, independence from the mesh is needed. In this contribution, the Johnson-Holmquist model (JH2) for brittle damage [2] has been implemented for the free open source software FEniCSx and is investigated in a high strain rate benchmark simulation. Mesh-convergence analyses show that displacements as well as the dissipated plastic energy do not converge with mesh-refinement. Following the gradient-enhancement approach by [1], a gradient-enhanced JH2 model which can be efficiently solved with explicit solvers is introduced and its advantages over the local models are discussed. Since many damage models for concrete share the damage mechanism of the JH2 model, the application of the regularization methods to more complex material models, like the RHT model [3], is also discussed. Advantages of a gradient-enhanced formulation to simulate dynamic strength increase of concrete, as suggested in [1], is discussed as well. T2 - ECCOMAS CONGRESS 2024 CY - Lisbon, Portugal DA - 03.06.2024 KW - Concrete Modeling KW - Explicit Dynamics KW - Gradient-Damage KW - Mesh Convergence PY - 2024 AN - OPUS4-64613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -