Conference Agenda

Flat slab punching of reinforced concrete structures is still a field of ongoing research. A huge amount of experimental data is available. Accompanying numerical 3D-simulations applying sophisticated concrete
models are computationally expensive and generally calibrated from the few respective experimental results. This prevents a generalization. An alternative approach is followed with this contribution. The computational costs are substantially reduced with a parametrized axisymmetric finite element modeling and a simplified material model for concrete. Only uniaxial compressive strength is required as input. Nevertheless, triaxial behavior and decisive nonlinear effects are considered. The application of the parametrized model is demonstrated with a representative example with detail results described. Furthermore, the model simplifications allow to perform simulations for 227 quite heterogeneous data sets collected from a wide range of experimental investigations. With respect to ultimate failure loads the simulation results in the mean show a good agreement with the experiments although with number of outliers. The model sets a base for gradual improvements by introducing further parameters step by step.

Understanding the phenomena that play a crucial role in the support of (precast) elements is crucial for the production and application of concrete elements. A lively debate is still ongoing about how it should work and how it seems to work in practice, where neither supports the other. Numerous examples of well-performing elements exist where the 10Ø or 100 mm criterion is not fulfilled, and exceptions are intro-duced by product standards, illustrating our lack of understanding. In the context of the introduction of a new national annex to EN 1992-1-1 (2023) in Belgium, a research project was launched to provide complementary information. A new analytical model and a new test setup have been developed, leading to a better understand-ing. Results of the tests support the proposed model based on a slip modulus. Based on the outcomes, signifi-cantly reduced anchoring lengths can be used.

This paper presents a thermodynamically-based lattice discrete particle model (LDPM) for simulating concrete fatigue from material to structural scale. The constitutive model is rigorously derived from thermodynamic potentials with explicit damage evolution driven by cumulative plastic strain at inter-aggregate level. The model is calibrated through comprehensive uniaxial compression simulations on prisms, accurately reproducing S-N curves, Sparks-Menzies relations, and realistic hysteretic behavior. At the structural level, the model predicts progressive damage evolution and stress redistribution in prestressed beams under subcritical cyclic loading. Key findings include: (i) the perfect alignment of material-to-structural fatigue results with the Sparks-Menzies relation provides theoretical justification for extrapolating laboratory fatigue relationships to engineering applications; (ii) damage dissipation emerges as a scale-invariant fundamental material property, offering a physically grounded alternative to empirical design approaches. The presented thermodynamic framework enables structural fatigue prediction based on material-level calibration, reducing reliance on costly full-scale testing while providing insights into concrete fatigue mechanisms.

The reliable validation and verification of simulation models is a key challenge in computational engineering, especially for complex materials and multi-physics problems. Existing approaches are often computationally intensive and tailored to specific setups, making generalization and objective comparison across models and codes difficult. This paper presents a concept for a reproducible and extensible benchmarking platform designed for any FEM or CFD-based simulation setup, with concrete modeling as a motivating example.
The platform aims to facilitate data exchange between experimentalists and simulation researchers, enable transparent comparison of models and implementations, and support referencing models with quality criteria in engineering standards. Key components include a machine-readable database structure for experimental metadata, standardized calibration procedures, and quality metrics that account for uncertainties. The platform supports integration of open-source constitutive model libraries into commercial codes, promoting interoperability and community-driven benchmarking. A federated database infrastructure enables sharing and publication of experimental and simulation results, with full provenance tracking to ensure reproducibility. Interactive visualization tools allow users to query, explore, and compare models and results. While the conceptual framework is well developed, a complete implementation is still in progress. Community contributions are needed to realize a broad set of benchmarks and develop tool-agnostic, machine-readable model definitions. The proposed platform aims to advance reproducibility, transparency, and robustness in computational modeling and simulation practice across engineering domains.