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Reinforced concrete (RC) columns, being axial-bearing components in buildings, are susceptible to damage and failure when subjected to blast loading. The failure of these columns can trigger a progressive collapse in targeted buildings. The primary objective of this study is to investigate the failure characteristics of laboratory-scale RC columns subjected to localized blast loading. The columns, with a length of 1500 mm and an outer diameter of 100 mm, are reinforced with 6 mm diameter longitudinal bars and 2 mm diameter steel ties. The blast loading is generated using an explosive-driven shock tube (EDST) positioned in front of the mid-span of the RC columns with a 30 g and 50 g charge. To capture the global response of the RC columns, high-speed stereoscopic DIC is used in addition to LVDTs. Furthermore, an FE model is developed using LS-DYNA R10.0 and validated against the experimental data. The results show that the proposed FE approach is able to reproduce the applied blast loading and the failure characteristics of the columns. The relative difference in column mid-span out-of-plane displacement between the FE model and the average measured data lies below 5%. Finally, the gray correlation method is conducted to assess the influence of various parameters on the blast resistance of the RC columns. [ABSTRACT FROM AUTHOR]

Reinforced concrete (RC) columns, being axial-bearing components in buildings, are susceptible to damage and failure when subjected to blast loading. The failure of these columns can trigger a progressive collapse in targeted buildings. The primary objective of this study is to investigate the failure characteristics of laboratory-scale RC columns subjected to localized blast loading. The columns, with a length of 1500 mm and an outer diameter of 100 mm, are reinforced with 6 mm diameter longitudinal bars and 2 mm diameter steel ties. The blast loading is generated using an explosive-driven shock tube (EDST) positioned in front of the mid-span of the RC columns with a 30 g and 50 g charge. To capture the global response of the RC columns, high-speed stereoscopic DIC is used in addition to LVDTs. Furthermore, an FE model is developed using LS-DYNA R10.0 and validated against the experimental data. The results show that the proposed FE approach is able to reproduce the applied blast loading and the failure characteristics of the columns. The relative difference in column mid-span out-of-plane displacement between the FE model and the average measured data lies below 5%. Finally, the gray correlation method is conducted to assess the influence of various parameters on the blast resistance of the RC columns.

• Design of an adequate experimental set-up to study the dynamic crush of a thin-walled tube, in particular, an empty metallic beverage can axially loaded. • Comparison between the effect of a low impact velocity and a dynamic load, on the deformation pattern, the mean crush load and the absorption capacity. • Study of the effect of the entrapped gases inside the MBC structure on the prediction of the mean crush load. The aim of this work is to study the response of a sacrificial cladding using metallic beverage can (MBC) as crushable core. A single MBC axially crushed is considered. An adequate experimental set-up is developed to examine the collapse pattern, the mean crush load and the absorption capacity of a single MBC under a blast load. A comparison with low velocity impact is discussed. The effect of both the entrapped gases inside the MBC and the crush velocity are investigated through analytical and numerical studies. A clear loading rate dependency of the mean crush load is observed. It varies from 0.94 kN to 1.35 kN by increasing the front plate velocity from 17 m/s (FP3) to 44 m/s (FP1). The effect of the entrapped gases inside the MBC structure increases the mean crush load, and, then, the transmitted load to the main structure. In addition to the dynamic material properties, the entrapped gases are considered for an accurate prediction of the mean crush load. Good correlation with the experimental results is observed. [ABSTRACT FROM AUTHOR]

The presented discussion concerns the behavior of a thin-walled hexagonal aluminum honeycomb structure subjected to blast loading. The shock wave affecting the structure is generated by detonation of the C4 charge in an explosive-driven shock tube (EDST). The EDST set-up is an instrumented device that makes it possible to study blast effects in more stable and repeatable conditions than those obtained in a free-air detonation. The formation of folds characteristic of a honeycomb deformation in the axial compression distributes the initial loading over a time period, which is considered as an efficient method of energy dissipation. The test configuration is modeled in the Ls-Dyna explicit code, which enables analysis of the mechanisms of energy absorption that accompanies structural deformation under a blast loading. The conclusions reached in the performed experimental and numerical investigation can be applied to the modeling and optimization of cellular structures used to mitigate blast loadings. [ABSTRACT FROM AUTHOR]

The need for efficient blast loading tools is increasing with the development of new protective techniques. Among these tools, one can cite the use of an explosive‐driven shock tube (EDST). The purpose of the present study is to define analytical equations to predict incident and reflected pressure and impulse generated at a laboratory scale EDST end in terms of the tube length, the tube diameter, the explosive mass, and the stand‐off distance. The formulae are obtained based on a dimensional analysis and a numerical parametric study. The analytical study is supported by a set of experiments, in order to validate the obtained analytical models. The EDSTs discussed in this study are open on both sides with diameters ranging from 0.15 to 0.50 m and a length ranging from 0.75 to 3 m. Two different tube sections, circular, and square, are examined. Explosive charges from 5 to 50 g of C4 are used. Within these conditions reflected pressures ranging from 0.15 to 11 MPa and reflected impulses ranging from 100 to 3000 Pa·s are obtained at the tube end. The obtained analytical equations are compared to several available results and formulae from the literature. In addition to that, a graphic representation is developed in order to estimate the tube geometry and the explosive mass necessary to generate a given couple of pressure–impulse at the tube end. [ABSTRACT FROM AUTHOR]