Abstract:In recent years, events such as the attack on the World Trade Center as well as many other attacks around the world have shown that terrorism-related activity is dramatically increasing. Such a situation makes necessary to study the effects of blast loading on complex urban environments. In this paper, the phenomenon of channelling in congested urban environments is studied. Channelling is a phenomenon that can significantly increase the destructive potential of a shock wave of an explosion. Hence, channelling… Show more
“…Remennikov (2003), Remennikov and Rose (2005) used the Air3D program to investigate the shielding and enhancement factor of adjacent structures on blast loads. Their analysis of numerical results showed consistency with that of Smith et al Programs like LS-DYNA and AUTODYN were also widely utilized to investigate the blast wave propagation in several city configurations (Codina et al, 2013;Fedorova et al, 2016;Johansson et al, 2007;Shi et al, 2007;Sklavounos and Rigas, 2004). During the last two decades, the rapid development of high-performance computers and various commercial programs have boosted the numerical simulating analysis on this topic, but numerical studies had stayed on several relatively simple street layouts.…”
Section: Blast Wave Propagating In Complex Urban Areasmentioning
Extreme explosion events result in demands for emergency rescue service. From the civil engineering perspective, a quick safety assessment of building structures in the explosion’s vicinity will provide the emergency rescue committee with concrete support to make scientific decisions. In this paper, three primary issues, namely, inverse analysis of explosive characteristics, blast wave propagation in complex urban areas and blast-induced damage identification, are reviewed. These are often performed stepwise and form a multi-step whole to assist the emergency rescue service. The paper begins by introducing the inverse analysis of explosives based on craters, building damages and seismic or acoustic records. In this step, explosive characteristics, for example, charge type, original time, yield and location, could be produced and input into blast load calculation in the next step. Then, the existing literature on blast wave propagation and blast load determination is presented with close attention to complex urban environments. It shows that the current study remains in its infancy and relies on advancement in computational fluid dynamics (CFD). Besides, pressure–impulse (P-I) diagrams which predict the structural damage based on the calculated blast loads are illustrated. Onsite damage detection techniques, such as visual inspection, non-destructive testing (NDT) and vibration-based methods, are also discussed. The paper ends with a discussion of the shortcomings of previous work and the outlooks of further work.
“…Remennikov (2003), Remennikov and Rose (2005) used the Air3D program to investigate the shielding and enhancement factor of adjacent structures on blast loads. Their analysis of numerical results showed consistency with that of Smith et al Programs like LS-DYNA and AUTODYN were also widely utilized to investigate the blast wave propagation in several city configurations (Codina et al, 2013;Fedorova et al, 2016;Johansson et al, 2007;Shi et al, 2007;Sklavounos and Rigas, 2004). During the last two decades, the rapid development of high-performance computers and various commercial programs have boosted the numerical simulating analysis on this topic, but numerical studies had stayed on several relatively simple street layouts.…”
Section: Blast Wave Propagating In Complex Urban Areasmentioning
Extreme explosion events result in demands for emergency rescue service. From the civil engineering perspective, a quick safety assessment of building structures in the explosion’s vicinity will provide the emergency rescue committee with concrete support to make scientific decisions. In this paper, three primary issues, namely, inverse analysis of explosive characteristics, blast wave propagation in complex urban areas and blast-induced damage identification, are reviewed. These are often performed stepwise and form a multi-step whole to assist the emergency rescue service. The paper begins by introducing the inverse analysis of explosives based on craters, building damages and seismic or acoustic records. In this step, explosive characteristics, for example, charge type, original time, yield and location, could be produced and input into blast load calculation in the next step. Then, the existing literature on blast wave propagation and blast load determination is presented with close attention to complex urban environments. It shows that the current study remains in its infancy and relies on advancement in computational fluid dynamics (CFD). Besides, pressure–impulse (P-I) diagrams which predict the structural damage based on the calculated blast loads are illustrated. Onsite damage detection techniques, such as visual inspection, non-destructive testing (NDT) and vibration-based methods, are also discussed. The paper ends with a discussion of the shortcomings of previous work and the outlooks of further work.
“…CFD (computational fluid dynamics) numerical models gained particular traction for blast applications in the early 2000s [85,86]. Obtaining reliable and precise outputs from CFD simulations typically comes at a high computational cost [87]; however, CFD is becoming an increasingly attractive and cost-effective research tool [88][89][90][91].…”
Section: General Computational Fluid Dynamics Studiesmentioning
Urban blasts have become a significant concern in recent years. Whilst free-field blasts are well understood, the introduction of an urban setting (or any complex geometry) gives rise to multiple blast wave interactions and unique flow complexities, significantly increasing the difficulty of loading predictions. This review identifies commonly agreed-upon concepts or behaviours that are utilised to describe urban shock wave propagation, such as channelling and shielding, in conjunction with exploring urban characterisation metrics that aim to predict the effects on global blast loading for an urban blast. Likewise, discrepancies and contradictions are highlighted to promote key areas that require further work and clarification. Multiple numerical modelling programmes are acknowledged to showcase their ability to act as a means of validation and a preliminary testing tool. The findings contained within this review aim to inform future research decisions and topics better.
“…A similar identification of zones was also undertaken for the case of an asymmetric explosion (Figure 12(b)). While the classification of zones was unchanged, their locations were slightly different.Figure 12.A schematic representation of the propagation of waves resulting from an explosive detonated at time t 0 in a street layout for (left) a symmetrically located charge and (right) an asymmetrical one (Codina et al, 2013). …”
Blast–obstacle interaction is a complex, multi-faceted problem. Whilst engineering-level tools exist for predicting blast parameters (e.g. peak pressure, impulse and loading duration) in geometrically simple settings, a blast wave is fundamentally altered upon interaction with an object in its path, and hence, the loading parameters are themselves affected. This article presents a comprehensive review of key research in this area. The review is formed of five main parts, each describing: the direct loading of a blast wave on the surface of a finite-sized structure; the modified pressure of the blast wave in the wake region of three main obstacle types – blast walls, obstacles, wall/obstacle hybrids; and finally, a brief description of some methods for predicting loading parameters in such blast–obstacle interaction settings. Key findings relate to the mechanisms governing blast attenuation, for example, diffraction, reflection (diverting away from the target structure), expansion/volume increase, vortex creation/growth, as well as obstacle properties influencing these, such as porosity (blockage ratio), obstacle shape, number of obstacles/rows, arrangement and surface roughness.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
