Samenvatting
Explosions in or near buildings can cause severe structural damage. Casualties may result not only from the blast itself but also from partial collapse and projected debris. The analysis and design of structures exposed to blast loads demand a thorough understanding of the behavior of structural elements, especially columns, as they are vital to maintaining overall stability. It is essential to understand how structural elements respond to blast loading in order to be able to protect both military and civilian infrastructure. Analytical models simplify predictions, yet they underestimate complex failure modes. Numerical simulations enable in-depth analysis, but they require calibration and validation. Small-scale tests offer a controlled and economical alternative to full-scale experiments, which are expensive and challenging to conduct.This dissertation investigates the dynamic response and failure mechanisms of circular RC columns subjected to blast loading under controlled laboratory conditions. The study is structured into four parts.
In the first part, the localized blast loading on the circular column is generated by an Explosive-Driven Shock Tube (EDST). The loading is studied using pressure sensors and Digital Image Correlation (DIC)-based background-oriented schlieren (BOS) technique. Different finite element modelling approaches in LS-DYNA are tested and validated against the experimental data to reproduce the applied loading. In the second part, an experimental setup is developed. The setup provides controllable boundary conditions for the columns while reducing light from the fireball and smoke from the detonation to limit interference with measurements. Small-scale RC columns are subjected to localized blast loading. Damage accumulation, including the initiation, propagation and timing of cracks as well as concrete ejection, is recorded. Stereoscopic high-speed DIC is used to track displacement fields on the surface of the columns. Based on the DIC measurements, the crack width opening is correlated with the column’s lateral out-of-plane displacement. The numerical model of RC columns is then validated to simulate their dynamic response. It is also used in a parametric study to assess the influence of column characteristics and loading parameters.
While the second part focuses on blast loading alone, it does not account for the axial load typically present in RC columns in service. The third part addresses this gap by testing circular RC columns under combined axial loading and localized blast loading. To assess the relevance of localized blast loading and identify potential differences in structural response, a modular blast load generator (MBLG), able to generate a distributed loading, is designed and developed in the final part. Tests are carried out on small-scale RC columns to compare their behavior under localized and distributed blast loading. It is shown that the EDST can be used to yield column behavior close to that obtained in the case of a distributed loading. Now that the response of columns to blast loading is well characterized, the developed setup can be used in future work to evaluate the effectiveness of protective measures, such as foams and wrapping, applied to RC columns.
| Datum prijs | 10 dec. 2025 |
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| Originele taal | Engels |
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| Begeleider | David Lecompte (Promotor) & Tine Tysmans (Promotor) |