Numerical Assessment of a Sustainable Blast Protection Wall

Terrorist attacks have increased in the past few years in different countries. Explosions are problem that has significant impact on human life, as well as the social and economic situations. Engineers have designed targeted structures to mitigate blast effects. However, design blast-resistant systems is pricey and not suitable choice in most cases. Therefore, install blast barriers to protect occupants and instructed can reduce casualties and losses. Most current studies have investigated the performance of multi-layer composite blast barriers composed of advanced materials, which is not only costly, but require skilled labour to construct. The present study conducts numerical analysis of eco-friendly composite blast protection wall to mitigate blast. The wall structure consists of two face-sheet of adobe brick and core layer of crushed recycled aggregate. The analysis framework includes three different blast wall models using ABAQUS®. The explosive charge of 1-kilogram TNT is placed at different standoff distances from 0.25 to 4.0 meter in front of the wall. The authors conclude sustainable materials to design blast barriers could be effective in reducing the intensity of explosions in certain blast scenarios. The thickness of the core layer and standoff distance have the main contribution to identify the blast response of the blast wall. For instance, the calculated out-of-plane displacement results showed when 1- kg TNT place at 0.5-m from the wall, and thickness of the core increases from 30-cm to 60-cm, the displacement decreases by 38.74%. While the acceleration decreases by 75% for the same range of increase of thickness of the core layer. The present study calls researchers to investigate the performance of low-cost, and environment-friendly materials to attenuate abnormal loads wether are man-made or natural hazards.

Towards an Understanding of the Effect of Adding a Foam Core on the Blast Performance of Glass Fibre Reinforced Epoxy Laminate Panels

This paper presents insights into the blast response of sandwich panels with lightweight foam cores and asymmetric (different thicknesses) glass fibre epoxy face sheets. Viscously damped elastic vibrations were observed in the laminates (no core), while the transient response of the sandwich panels was more complex, especially after the peak displacement was observed. The post-peak residual oscillations in the sandwich panels were larger and did not decay as significantly with time when compared to the equivalent mass laminate panel test. Delamination was the predominant mode of failure on the thinner facesheet side of the sandwich panel, whereas cracking and matrix failure were more prominent on the thicker side (which was exposed to the blast). The type of constituent materials used and testing conditions, including the clamping method, influenced the resulting failure modes observed. A probable sequence of damage in the sandwich panels was proposed, based on the transient displacement measurements, a post-test failure analysis, and consideration of the stress wave propagation through the multilayered, multimaterial structure. This work demonstrates the need for detailed understanding of the transient behaviour of multilayered structures with significant elastic energy capacity and a wide range of possible damage mechanisms. The work should prove valuable to structural engineers and designers considering the deployment of foam-core sandwich panels or fibre reinforced polymer laminates in applications when air-blast loading may pose a credible threat.

Blast mitigation using polymeric 3D printed auxetic re-entrant honeycomb structures: A preliminary study

Protection of critical infrastructure in an urban environment is a challenging task, specifically against the vehicle bourne improvised explosive device threat. To design infrastructure to withstand this evolving threat, novel solutions and advanced materials need to be developed. One such material of interest are auxetics. This study experimentally analysed the mitigation of blast response of auxetic re-entrant honeycomb structures, with geometries varying between −ve 30° and +ve 30° using additive manufacturing (3D printing) techniques and non-explosive loading via shock tube. Re-entrant auxetic structures (−ve 15°) exhibited repeatable blast mitigation of 23% and reduced the transmitted pressure and impulse of the blast wave. Further highlighting their potential application as a protective measure to enhance a structures blast survivability.

An RHT-Model-Based Equivalent Parameter Scheme for Blast Response Simulation of RC Frames

In this paper, a novel equivalent parameter scheme based on the Riedel–Hiermaier–Thoma (RHT) model is proposed for blast response simulations of reinforced concrete (RC) frames. Considering the strengthening effect of longitudinal and stirrup reinforcements on concretes, constitutive parameters in the RHT model are modified to homogenize RC components based on reasonable simplifications and numerical tests. Numerical results of RC beams illustrate that this scheme significantly improves the computational efficiency and effectively predicts real explosion response behaviors with high accuracy. The scheme is then employed for the blast simulation of an RC frame with multiple components with results compared with those of real frame experiments to further demonstrate its reliability. Owing to its efficiency and accuracy, the present RHT-model-based equivalent parameter scheme can serve as a feasible tool to conduct blast response analysis of the RC frame and guide the corresponding anti-explosion designs.