Journal articles on the topic 'Air blast loads'
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Dobrociński, Stanisław, and Leszek Flis. "Numerical Simulations of Blast Loads from Near-Field Ground Explosions in Air." Studia Geotechnica et Mechanica 37, no. 4 (December 1, 2015): 11–18. http://dx.doi.org/10.1515/sgem-2015-0040.
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Abstract Numerical simulations of air blast loading in the near-field acting on the ground have been performed. A simplified blast model based on empirical blast loading data representing spherical and hemispherical explosive shapes has been simulated. Conwep is an implementation of the empirical blast models presented by Kingery and Bulmash, which is also implemented in the commercial code LS-DYNA based on work done by Rahnders-Pehrson and Bannister. This makes it possible to simulate blast loads acting on structures representing spherical and hemispherical explosive shapes of TNT with reasonable computational effort as an alternative to the SPH and Eulerian model. The CPU time for the simplified blast model is however considerably shorter and may still be useful in time consuming concept studies. Reasonable numerical results using reasonable model sizes can be achieved not only for modelling near-field explosions in air but most areas of geotechnical. Calculation was compared with blast SPH and Eulerian model.
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Ngo, Tuan, Priyan Mendis, A. Gupta, and J. Ramsay. "Blast Loading and Blast Effects on Structures – An Overview." Electronic Journal of Structural Engineering, no. 1 (January 1, 2007): 76–91. http://dx.doi.org/10.56748/ejse.671.
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The use of vehicle bombs to attack city centers has been a feature of campaigns by terrorist organizations around the world. A bomb explosion within or immediately nearby a building can cause catastrophic damage on the building's external and internal structural frames, collapsing of walls, blowing out of large expanses of windows, and shutting down of critical life-safety systems. Loss of life and injuries to occupants can result from many causes, including direct blast-effects, structural collapse, debris impact, fire, and smoke.The indirect effects can combine to inhibit or prevent timely evacuation, thereby contributing to additional casualties. In addition, major catastrophes resulting from gas-chemical explosions result in large dynamic loads, greater than the original design loads, of many structures. Due to the threat from such extreme loading conditions, efforts have been made during the past three decades to develop methods of structural analysis and design to resist blast loads. The analysis and design of structures subjected to blast loads require a detailed understanding of blast phenomena and the dynamic response of various structural elements. This paper presents a comprehensive overview of the effects of explosion on structures. An explanation of the nature of explosions and the mechanism of blast waves in free air is given. This paper also introduces different methods to estimate blast loads and structural response.
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Mohottige, Nimasha Weerasingha, Chengqing Wu, and Hong Hao. "Characteristics of Free Air Blast Loading Due to Simultaneously Detonated Multiple Charges." International Journal of Structural Stability and Dynamics 14, no. 04 (April 2, 2014): 1450002. http://dx.doi.org/10.1142/s0219455414500023.
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Extensive research has been conducted to investigate the characteristics of blast load due to single charge explosion, including numerical simulations and experimental blast tests in both unconfined and confined environments. Further, available guidelines for blast resistant design such as UFC-3-340-02 (2008) and ASCE 59-11 (2011) provide details to predict blast loads on a structure subjected to single charge explosion. However, blast load characteristics due to multiple charge explosions are poorly discussed in available literature. In this paper, commercially available Hydrocode, AUTODYN is calibrated for single charge explosions. Based on a comparison between numerical simulation and UFC prediction, correction factors for peak reflected pressure and positive reflected impulse as a function of charge weight, scaled distance and mesh size of the numerical model are proposed to minimize the errors in simulations. The calibrated AUTODYN model is then used to conduct parametric studies to investigate the effects of charge weight, scaled distance, number of charges and distance between the charges on the characteristics of free air blast load due to simultaneous detonated multiple charges. Numerical simulation results are used to derive analytical formulas for predictions of peak reflected pressure ratio and positive reflected impulse ratio between single and multiple explosions. The discussion is made on characteristics of free air blast load due to simultaneous detonated multiple charges.
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Hao, Yifei, Hong Hao, Yanchao Shi, Zhongqi Wang, and Ruiqing Zong. "Field Testing of Fence Type Blast Wall for Blast Load Mitigation." International Journal of Structural Stability and Dynamics 17, no. 09 (October 23, 2017): 1750099. http://dx.doi.org/10.1142/s0219455417500997.
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To protect structures from external explosions, solid protective barriers have been demonstrated by experimental and numerical studies to be able to effectively mitigate blast loads on structures behind them. However, to protect against blast loads, barriers normally need to be designed to have high structural resistance and ductility. This often requires bulky and heavy protective barriers which are not only highly costly but also often not appropriate for application in downtown areas as they are not friendly to city planning or appearance. Fence type blast wall consisting of structural columns was recently proposed and its effectiveness in mitigating blast loads was investigated through numerical simulations. It was found that the wave–fence interaction and interference of waves significantly reduced the wave energy when the blast wave passed through the fence blast wall. To further investigate the effectiveness and applicability of fence type blast wall as a highly potential technology for structural protection in an urban area, field tests have been conducted and results are reported in this paper. Columns with circular and triangular cross-sections were adopted to build fence blast walls. In addition, a masonry wall was also constructed as solid barrier for comparison. Hemispherical TNT explosive weighing 1.0 kg with different stand-off distances was detonated on the ground to generate the blast load. Blast overpressures in free air, behind the fence blast wall and behind the masonry wall were recorded by pressure sensors. The effectiveness of the fence blast wall in reducing blast wave and protecting structures was demonstrated by the test data.
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Anas, S. M., Mehtab Alam, and Mohammad Umair. "Air-blast and ground shockwave parameters, shallow underground blasting, on the ground and buried shallow underground blast-resistant shelters: A review." International Journal of Protective Structures 13, no. 1 (October 7, 2021): 99–139. http://dx.doi.org/10.1177/20414196211048910.
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Weak political systems and poor governance in certain developing countries are found to have a war-like environment where structures are being targeted by blasts and bombs. Industrial blasts due to frail know-how and mishandlings are also quite common. Recent accidental explosions like that occurred at the Beirut Port, Lebanon (August 2020); ammunition depot in the outskirt of the Ryazan City of Russia (November 2020) are of concern for the safety of adjacent building infrastructure and their users. Such intense loading events cause damage to certain elements of a structure which may result in disproportionate or progressive collapse. It necessitates a clear understanding of the phenomenon of the blast and extreme loads induced out of it, and response of the target structure under such loadings. In this study, the state of research on air-blast and ground shockwave parameters, shallow underground blasting, and on the ground and buried shallow blast-resistant shelters are presented. The phenomenon of the self-Mach-reflection of the explosion, loading parameters and empirical blast models available in the open literature followed by the damage criteria for the buildings subjected to the underground blasting and available peak particle velocity (PPV) prediction models have been discussed. To make the application of advanced materials such as fibrous concrete, ultra-high performance concrete, FRP composites, etc., it is important to comprehend the existing blast/shock-resistant shelters and their response under such loading. The shelters are primarily designed by incorporating features of the materials like high degree of deformability/ductility, use of the shock-isolation panels and the mechanism for controlling crack formations. Finally, conclusions and recommendations for future studies are summarised. This paper presents prospects to engineers, town planners, researchers, policymakers and members of the core drafting sectional committees to understand the phenomenon of the blast and extreme loads induced out of it.
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Akhlaghi, Ebrahim. "Numerical Simulation of Air Shock Wave Propagation Effects in Reinforced Concrete Columns." Journal of Modeling and Optimization 12, no. 1 (June 15, 2020): 12–22. http://dx.doi.org/10.32732/jmo.2020.12.1.12.
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Reinforced concrete has been shown to be a desirable material of choice in blast resistant structures due to its availability, relatively low cost, and its inherent ability to absorb energy produced by explosions. Most research work investigating the behaviour of reinforced concrete columns to blast loading have concentrated on their response to planar loading from far-field explosions. Limited amount of work is available on the effects of near-field explosion on the behaviour of reinforced concrete columns. This study is aimed to investigate effects of explosive loads on RC column by using ALE method. Commercial finite element package, LS-DYNA is used to simulate the behavior of blast wave on RC columns. Numerical simulation is validated against experimental work done in literature. The experience gained from this research provides valuable information for the development of the finite element modeling of real blast load effects on RC columns.
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Chirica, Ionel, and Elena Felicia Beznea. "Structural Solutions for Ship Hull Plates Strengthening, under Blast Loads." Key Engineering Materials 601 (March 2014): 76–79. http://dx.doi.org/10.4028/www.scientific.net/kem.601.76.
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The paper presents selected results of a study concerning the protective capacity of ship hull plates, made out of layered composite plates. A scenario to evaluate the behaviour of the ship structure plate under blast loading is presented. The nonlinear analysis on a 3-D FEM model by using composite elements was performed. The methodology for the blast pressure charging and the mechanism of the blast wave in free air are given. The space pressure variation is determined by using Friedlander exponential decay equation. According to the methods used in this paper an individual pressure-time history to each element based on its distance from the blast is assigned. The dynamic response of the composite plate is shown.
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Clough, Laurence G., and Simon K. Clubley. "Steel column response to thermal and long duration blast loads inside an air blast tunnel." Structure and Infrastructure Engineering 15, no. 11 (July 11, 2019): 1510–28. http://dx.doi.org/10.1080/15732479.2019.1635627.
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DENG, RONG-BING, and XIAN-LONG JIN. "THREE-DIMENSIONAL SIMULATION OF CONDENSED EXPLOSIVE-INDUCED FLOW PROPAGATION AND INTERACTION WITH GLASS CURTAIN WALL." Modern Physics Letters B 24, no. 09 (April 10, 2010): 833–48. http://dx.doi.org/10.1142/s0217984910022895.
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In order to carry out blast response of curtain wall, the first step is to understand the complex flow of the air blasts around the structures and predict the blast loads acting on the structures. But in earlier studies related to blast resistant design of glass curtain wall, blast flow induced by condensed explosive is not taken into account due to expensively computational resources required. Based on high performance computing, this paper presents a new three-dimensional numerical simulation method of condensed explosive-induced flow propagation and impact on a complex glass curtain wall, where the fluid is represented by solving Navier–Stokes equations with a multimaterial arbitrary Lagrangian–Eulerian (ALE) formulation. In particular, the whole analytical model consists of condensed explosive, air, detailed curtain wall system, and ground, which comprehensively represents the real fluid–structure interaction environment. Final calculation has been performed on the Dawning 4000A supercomputer based on the domain decomposition method. The flow mechanisms of blast wave rounding curtain wall is visualized and the simulated pressure history of gauge is in good agreement with the experimental result which validates this method. The present method is shown to be a useful tool for blast resistance design of curtain wall in the future.
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Lee, Chang-Yull, Jin-Young Jung, and Se-Min Jeong. "Active Vibration Suppression of Stiffened Composite Panels with Piezoelectric Materials under Blast Loads." Applied Sciences 10, no. 1 (January 4, 2020): 387. http://dx.doi.org/10.3390/app10010387.
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Transient responses of stiffened panels with piezoelectric sensors and actuators are studied under normal blast loads. The air vehicles could be exposed to blast pulses generated by an explosion or shock-wave disturbances. Thus, active vibration suppression of the vehicles is important under blast loadings. The structural model is designed as a laminated composite panel with lead zirconate titanate (PZT) piezoceramic layers embedded on both top and bottom surfaces. A uniformly distributed blast load is assumed over the whole of the panel surface. The first-order shear deformation theory of plate is adopted, and the extended Hamilton’s principle is applied to derive the equations of motions. The numerical model is verified by the comparison with previous data. Using linear quadratic regulator (LQR) control algorithm, vibration characteristics and dynamic responses are compared. As piezoelectric patches are attached on the whole of the surface, the effect of the stiffener’s location is studied. Furthermore, the influences of the patch’s positions are also investigated through subjection to the blast wave. From various results, in order to get the best control performances, the research aims to find the optimum position of sensor and actuator pairs that is most effective under blast load environments.
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Larcher, Martin, Martien Teich, Norbert Gebbeken, George Solomos, Folco Casadei, Grecia A. Falcon, and Sonja L. Sarmiento. "Simulation of Laminated Glass Loaded by Air Blast Waves." Applied Mechanics and Materials 82 (July 2011): 69–74. http://dx.doi.org/10.4028/www.scientific.net/amm.82.69.
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In this paper, several material models are analyzed in order to represent and compare the behaviour of laminated glass subjected to blast loads. LS-DYNA and EUROPLEXUS are used for numerical simulation. These codes have different capabilities to describe the mechanical problem, especially the failure behaviour. The results of the simulations are compared to laboratory experimental results in order to validate the accuracy of the material models.
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Shuaib, Mujtaba M., Steeve Chung Kim Yuen, and Gerald N. Nurick. "Numerical Simulation of Blast Loaded CFRP Retrofitted Steel Plates." MATEC Web of Conferences 347 (2021): 00038. http://dx.doi.org/10.1051/matecconf/202134700038.
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This paper reports on the results of a numerical study to simulate the response of carbon fibre reinforced polymer (CFRP) retrofitted steel plates to applied blast loads using finite element software, LS-DYNA. The results of the simulation were validated against plate response and magnitude of deformation obtained from previous experiments. The uniform blast load was generated in the experiment by detonating a cylindrical charge down the end of a square tube. The finite element code LS-DYNA was used to simulate the structural response of the respective blast structures. For the numerical model, the blast load was simulated using the mapping feature available in LS-DYNA for the multi-material arbitrary Lagrangian-Eulerian (MM-ALE) elements which significantly reduced the size of the air domain in the model. The simulations showed a satisfactory correlation with the experiments for the blast results and post-failure deformations that occurred in CFRP retrofitted steel plates.
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Marín, Juan Andrés, Rafael Rodríguez, María B. Díaz, and Saray Antón. "Empirical Attenuation Law for Air Blast Waves Due to the Detonation of Explosives Outdoors." Applied Sciences 12, no. 18 (September 12, 2022): 9139. http://dx.doi.org/10.3390/app12189139.
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The detonation of explosives in the open air was studied, analyzing different amounts of explosives detonated at different distances, monitoring the overpressure or air blast wave generated with the aim of determining a model, which allows to establish safety zones. A series of tests measuring the air wave with different loads and sensors placed at various distances from the origin of the explosion were carried out. The work was focused on designing full-scale trials that allowed to develop a predictive empirical method based on the calculation model of the equivalent mass of TNT. A total of 18 different gelatinous dynamite charges, placing the sensor at six different distances from the origin of the explosion, produced a total of 90 tests measuring the air wave produced by the detonation of gelatinous dynamite. Later, the outdoor detonation of 10 TNT explosive charges was analyzed to extend the model and improve its scope. With all this, it has been possible to develop a predictive model that allows assessing the overpressure generated by the detonation of a TNT-equivalent explosive charge. The results are useful to predict the air blast wave in common open-air blasts, such as those carried out with shaped charges to demolish metallic structures. On the other hand, the results are also useful to determine the air blast wave overpressure in the case of large explosive charges detonated in the open air, such as accidental explosive detonation or terrorist bombs. It is important to point out the relevance of the results achieved after the detonation of large explosive charges (more than 80 kg) simulating a type of bomb frequently used by terrorists. Reproducing the explosion on a real scale, the results are fully representative of the overpressure produced by an explosion of these characteristics without the need of extrapolating the results of tests with small loads. In addition, the detonation was carried out with TNT, which can serve as a standard to compare with any other type of explosive.
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Kapoor, Hitesh, Sangeon Chun, Michael R. Motley, Rakesh K. Kapania, and Raymond H. Plaut. "Nonlinear Response of Highly Flexible Structures to Air Blast Loads: Application Shelters." AIAA Journal 44, no. 9 (September 2006): 2034–42. http://dx.doi.org/10.2514/1.18480.
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Houlston, Robin. "Finite strip analysis of plates and stiffened panels subjected to air-blast loads." Computers & Structures 32, no. 3-4 (January 1989): 647–59. http://dx.doi.org/10.1016/0045-7949(89)90353-2.
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Xiao, Li, Wen Zhong Qu, and Jian Gang Wang. "Experimental and Numerical Studies on the Reinforced Concrete Frames Subjected to Blast Loads." Applied Mechanics and Materials 157-158 (February 2012): 1173–77. http://dx.doi.org/10.4028/www.scientific.net/amm.157-158.1173.
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Terrorist bombing attacks will endanger and may even destroy the target building structures, resulting in economic loss and casualties. Typical columns and floor slab systems are not designed to resist the complex blast loading. So, in recent years, the effects of blast on conventional public buildings are focused on. In this paper,a two-bay,one-story reinforced concrete frame structure which is used to model a portion of a typical reinforced concrete frame structural system is used to investigate the blast response. The experiments are conducted on two models, allowing a variation in explosives standoff and explosives charge. In each experiment,the blast pressure values are recorded and the degree of damage of the frames are studied. According to the two kinds of experiments, two numerical models are established. ALE method which considers the interaction of the explosive, the air, and the structure is applied.Structure response analyses are performed using the large deformation finite-element computer code, LS-DYNA. The numerical results are compared with the experiment results, and a good agreement is obtained. The calculating results also demonstrate that some experimental value is unreasonable.
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Chen, Dapeng, Li Chen, Qin Fang, Yuzhou Zheng, and Teng Pan. "Uniform loading on the reinforced concrete beam produced by the specific cylinder-shaped rubber bags fully filled with air or water." Advances in Structural Engineering 23, no. 9 (February 6, 2020): 1934–47. http://dx.doi.org/10.1177/1369433220904006.
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The bending behavior of reinforced concrete beams under uniform pressure is critical for the research of the blast-resistance performance of structural components under explosive loads. In this study, a bending test of five reinforced concrete beams with the dimensions of 200 mm (width) × 200 mm (depth) × 2500 mm (length) under uniform load produced by a specific cylinder-shaped rubber bag filled with air or water was conducted to investigate their flexural performances. An air bag load was applied to three of the reinforced concrete beams, a water bag load was applied to one reinforced concrete beam, and the remainder beam was subjected to the 4-point bending load. The experimental results highlighted that the air bag and water bag loading methods can be used to effectively apply uniform loads to reinforced concrete beams. Moreover, the stiffness of the air bag was improved by 123% in accordance with the initial pressure increases from 0.15 to 0.45 MPa. In addition, a finite element model of the test loading system was established using ABAQUS/Standard software. Moreover, the critical factors of the air bag loading method were analyzed using the numerical model. The calculated results were found to be in good agreement with the test data. The established finite element model can therefore be used to accurately simulate the action performances of the uniform loading technique using rubber bags filled with air or water.
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Amadio, Claudio, and Chiara Bedon. "Dynamic Response of Cable-Supported Façades Subjected to High-Level Air Blast Loads: Numerical Simulations and Mitigation Techniques." Modelling and Simulation in Engineering 2012 (2012): 1–13. http://dx.doi.org/10.1155/2012/863235.
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A glazing façade subjected to blast loads has a structural behaviour that strongly differs from the typical response of a glazing system subjected to ordinary loads. Consequently, sophisticated modelling techniques are required to identify correctly its criticalities. The paper investigates the behaviour of a cable-supported façade subjected to high-level blast loading. Nonlinear dynamic analyses are performed in ABAQUS/Explicit using a sophisticated FE-model (M01), calibrated to dynamic experimental and numerical results. The structural effects of the total design blast impulse, as well as only its positive phase, are analyzed. At the same time, the possible cracking of glass panels is taken into account, since this phenomenon could modify the response of the entire façade. Finally, deep investigations are dedicated to the bearing cables, since subjecting them to elevated axial forces and their collapse could compromise the integrity of the cladding wall. Based on results of previous studies, frictional devices differently applied at their ends are presented to improve the response of the façade under the impact of a high-level explosion. Structural effects of various solutions are highlighted through dynamic simulations. Single vertical devices, if appropriately calibrated, allow reducing significantly the axial forces in cables, and lightly the tensile stresses in glass panes.
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Teich, Martien, Norbert Gebbeken, and Martin Larcher. "Aerodynamic Damping and Fluid-Structure Interaction of Blast Loaded Flexible Structures." Applied Mechanics and Materials 82 (July 2011): 491–96. http://dx.doi.org/10.4028/www.scientific.net/amm.82.491.
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This paper analyses the e ects of air-structure interaction of systems subjectedto weak blast loads. While these coupling e ects are negligible for typical steel or concretestructures, they may dominate the dynamic response of lighter and more exible (compliant)systems like membranes, blast curtains or cable facades. For these light and exible systems,a classical decoupled analysis, i.e., neglecting the inuence of the surrounding air, might sig-ni cantly overestimate the deections and strains. However, we show that the coupling e ectscan be accounted for by basically adding a viscous aerodynamic damping force. We discussand compare two approaches how to obtain the aerodynamic damping term. With decreasingstructural sti ness and mass, the damping contribution of air increases signi cantly. The resultsof Hydrocode simulations are presented, and an outlook into further areas of research is given.
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Zakrisson, Björn, Bengt Wikman, and Hans-Åke Häggblad. "Numerical simulations of blast loads and structural deformation from near-field explosions in air." International Journal of Impact Engineering 38, no. 7 (July 2011): 597–612. http://dx.doi.org/10.1016/j.ijimpeng.2011.02.005.
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Slavik, Todd P. "A coupling of empirical explosive blast loads to ALE air domains in LS-DYNA®." IOP Conference Series: Materials Science and Engineering 10 (June 1, 2010): 012146. http://dx.doi.org/10.1088/1757-899x/10/1/012146.
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Bedon, Chiara, and Claudio Amadio. "Exploratory numerical analysis of two-way straight cable-net façades subjected to air blast loads." Engineering Structures 79 (November 2014): 276–89. http://dx.doi.org/10.1016/j.engstruct.2014.08.023.
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Coffield, Amy, and Hojjat ADELI. "IRREGULAR STEEL BUILDING STRUCTURES SUBJECTED TO BLAST LOADING." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 22, no. 1 (December 18, 2015): 17–25. http://dx.doi.org/10.3846/13923730.2015.1073172.
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In seismic design, structural irregularity has been found to have a significant influence on structural response. The impact of structural irregularity on the global response of steel frame structures subjected to blast loading has not been examined. In the paper, six seismically designed steel framed structures are considered: moment resisting frames (MRF), concentrically braced frames (CBF) and eccentrically braced frames (EBF) each with geometric irregularity in the plan and with a geometric irregularity in the elevation. The blast loads are assumed to be unconfined, free air burst detonated 15 ft from one of the center columns. The structures are modeled and analyzed using the Applied Element Method, which allows the structure to be examined during and through structural failure. A plastic hinge analysis is performed as well as a comparative analysis observing roof deflection and acceleration to determine the effect of geometric irregularity under extreme blast loading conditions. Two different blast locations are examined. Conclusions of this research are a concentrically braced frame provides somewhat of a higher level of resistance to blast loading for irregular structures and geometric irregularity has an impact on the response of a structure subjected to blast loading.
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Schulz, Erich J., Richard C. Celotto, Morgan P. O'Connor, and John A. Malone. "Adapting Commercial Shipbuilding Practices to Warship Design – Evaluation of a Hybrid Navy-Commercial Collar Detail." Journal of Ship Production 16, no. 04 (November 1, 2000): 207–21. http://dx.doi.org/10.5957/jsp.2000.16.4.207.
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An investigation was carried out to determine the applicability of certain commercial construction techniques to naval ships with regard to their capability to withstand weapons effects loads. Typical commercial structural details require less welding and fitting, are less labor intensive, and are therefore less expensive to construct than naval structural details. However, structural details used on naval ships must adequately resist loads that are different from those a commercial ship would encounter, specifically shock and whipping loads due to underwater explosions, and blast from air explosions. This paper documents the limited-scope investigation performed that included design, analysis, and shock testing of a candidate commercial structural detail to replace the Navy standard detail, specifically the collar used in joint connections.
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Fouad, Marco, Mohamed N. Fayed, Gehan A. Hamdy, and Amr Abdelrahman. "Effect of Blast Loading on Seismically Detailed RC Columns and Buildings." Civil Engineering Journal 7, no. 8 (August 1, 2021): 1406–25. http://dx.doi.org/10.28991/cej-2021-03091733.
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Explosions caused by standoff charges near buildings have drastic effects on the internal and external structural elements which can cause loss of life and fatal injuries in case of failure or collapse of the structural element. Providing structural elements with blast resistance is therefore gaining increasing importance. This paper presents numerical investigation of RC columns with different reinforcement detailing subjected to near-field explosions. Detailed finite element models are made using LS-DYNA software package for several columns having seismic and conventional reinforcement detailing which were previously tested under blast loads. The numerical results show agreement with the published experimental results regarding displacements and damage pattern. Seismic detailing of columns enhances the failure shape of the column and decrease the displacement values compared to columns with conventional reinforcement detailing. Further, the effect of several modeling parameters are studied such as mesh sensitivity analysis, inclusion of air medium and erosion values on the displacements and damage pattern. The results show that decreasing the mesh size, increasing erosion value and inclusion of air region provide results that are very close to experimental results. Additionally, application is made on a slab-column multistory building provided with protective walls having different connection details subjected to blast loads. The results of this study are presented and discussed. Use of a top and bottom floor slab connection of protective RC walls are better than using the full connection at the four sides to the adjacent columns and slabs. This leads to minimizing the distortion and failure of column, and therefore it increases the chance of saving the building from collapse and saving human lives. Doi: 10.28991/cej-2021-03091733 Full Text: PDF
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Cerik, Burak Can. "Damage assessment of marine grade aluminium alloy-plated structures due to air blast and explosive loads." Thin-Walled Structures 110 (January 2017): 123–32. http://dx.doi.org/10.1016/j.tws.2016.10.021.
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Li, Yongqing, Changhai Chen, Hailiang Hou, Yuansheng Cheng, Haopeng Gao, Pan Zhang, and Ting Liu. "The Influence of Spraying Strategy on the Dynamic Response of Polyurea-Coated Metal Plates to Localized Air Blast Loading: Experimental Investigations." Polymers 11, no. 11 (November 15, 2019): 1888. http://dx.doi.org/10.3390/polym11111888.
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Polyurea has attracted considerable attention owing to its potential applications in protective fields to improve the resistant performance of structures subjected to damage loads resulting from intentional or accidental explosions. However, different spraying strategies of polyurea may lead to significant differences in overall resistance performance of polyurea-coated structures, and the underlying mechanisms have not been clear until now. This study aims to elucidate the influence of spraying strategy, i.e., spraying area, spraying thickness, and spraying interface condition, on the dynamic response of polyurea-coated steel plates under localized air blast loading. Three types of plates manufactured using different spraying strategies were adopted to evaluate their blast-resistant performance. The spraying strategies used were (i) whole-area spraying, (ii) partial-area spraying, and (iii) in-contact backing of polyurea on the rear surfaces of steel plates. In addition, the influence of spraying thickness of polyurea for whole-area sprayed plates was evaluated. The energy absorbing mechanisms of polyurea backing layers were highlighted. The energy absorption of plates was quantitatively analyzed. The results show that the air blast resistances of whole-area sprayed and in-contact backed plates are both superior to, whereas that of partial-area sprayed plates is inferior to, bare steel counterparts. A suitable spraying thickness of polyurea can significantly reduce the damage of the front steel layer, whereas excessive spraying thickness decreases the overall air blast resistance of plates. The polyurea backing layer exhibits favorable performance in absorbing energy under a whole-area spraying condition. This study provides useful guidance for the design of polyurea-coated metal plates in engineering applications.
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Alogla, Ageel, Mahmoud Helal, Mohamed Mokbel ElShafey, and Elsayed Fathallah. "Numerical Analysis for Critical Structures Protection against Blast Loading Using Metallic Panels." Applied Sciences 10, no. 6 (March 20, 2020): 2121. http://dx.doi.org/10.3390/app10062121.
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The need for building protection against blast loads is a crucial issue nowadays due to the escalating threat of terrorist attacks, which affect people’s lives and critical structures. Consequently, design of protective panels to segregate building façades from the effect of a nearby explosion is required. Such design mainly depends on the ability of protective panels to mitigate and diffract the blast wave before reaching building façades. Five protective panel models with different designs, referred to as the Combined Protection System (CPS), are introduced in this paper. The main objective of this research was to achieve a design that could sustain a blast load with minimum plastic deformations. The introduced CPS designs included two steel plates linked by connector plates. The CPS dimensions were 3 m × 3 m × 0.35 m, representing length, width, and height, respectively. After that, the successful panel design was supported by placing these panels onto a masonry wall in different configurations. The protective panels were tested against 50 kg of trinitrotoluene (TNT) with a standoff distance of one meter. The final run of the optimum model was carried out using a blast load equivalent to 500 kg of TNT. The air–structure interactions were simulated using finite element analysis software called “ANSYS AUTODYN”, where the deformation of the panel was the governing parameter to evaluate the behavior of different designs. The analysis showed minimum deformation of the CPS design with vertical and horizontal connecting plates in a masonry wall distanced at 500 mm from the panel. However, the other designs showed promising results, which could make them suitable for critical structural protection on different scales.
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Coffield, Amy, and Hojjat Adeli. "AN INVESTIGATION OF THE EFFECTIVENESS OF THE FRAMING SYSTEMS IN STEEL STRUCTURES SUBJECTED TO BLAST LOADING." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 20, no. 6 (December 20, 2014): 767–77. http://dx.doi.org/10.3846/13923730.2014.986667.
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The effectiveness of different framing systems for three seismically designed steel frame structures subjected to blast loading is investigated. The three faming systems considered are: a moment resisting frame (MRF), a concentrically braced frame (CBF) and an eccentrically braced frame (EBF). The blast loads are assumed to be unconfined, free air burst detonated 15 ft (4.572 m) from one of the center columns. The structures are modeled and analyzed using the Applied Element Method, which allows the structure to be evaluated during and through failure. Failure modes are investigated through a plastic hinge analysis and member failure comparison. Also, a global response analysis is observed through comparison of roof deflections and accelerations. A conclusion of this research is that braced frames provide a higher level of resistance to the blast loading scenario investigated in this research. Both the CBF and EBF had a smaller number of failed members and plastic hinges compared to the MRF. They also had smaller roof deflection and acceleration. The CBF yielded the fewest number of plastic hinges but the EBF had a slightly fewer number of failed members.
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Liplenko, M. A., A. N. Borodenko, and G. V. Mosolov. "The calculation of loads on buildings and structures caused by outdoor explosions of the fuel-air mixture." Pozharovzryvobezopasnost/Fire and Explosion Safety 31, no. 1 (March 17, 2022): 88–98. http://dx.doi.org/10.22227/0869-7493.2022.31.01.88-98.
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Introduction. An important engineering task, to be solved in the process of designing buildings and structures for hazardous industrial facilities, is to determine values of loads caused by outdoor explosions of the fuel-air mixture. Nowadays software packages, that use the computational fluid dynamics (CFD) approach, are widely applied in the design practice to assess various effects on building structures. In this regard, it is necessary to develop a load calculation method, that employs numerical simulation, and verify it in comparison with the experimental data.Goals and objectives. The purpose of this work is to use the method of computational fluid dynamics to analyze external sympathetic detonation loads on various types of buildings and structures.The body of the article. The article addresses the “compressed balloon” method used to analyze loads, caused by outdoor explosions of gas. Dependencies, proposed in the article, are needed to set the input data and make numerical calculations using the computational fluid dynamics (CFD) technique. The numerical modeling of various experiments in the ANSYS Fluent software package was conducted. The authors compared the results of numerical modeling and standard engineering methods with various experiments to assess the accuracy of the “compressed balloon” method used to analyze an outdoor detonation explosion.Conclusions. The authors have proven the qualitative and quantitative convergence of the numerical model of blast wave propagation and the experimental data. This calculation method allows to accurately apply the pressure profile to any surface of a building or structure in the course of an outdoor detonation explosion and estimate the bearing capacity of building structures. The proposed method can be used in the design of buildings or structures that feature various configurations.
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Mubarok, Muhammad Arif Husni, Aditya Rio Prabowo, Teguh Muttaqie, and Nurul Muhayat. "Dynamic Structural Assessment of Blast Wall Designs on Military-Based Vehicle Using Explicit Finite Element Approach." Mathematical Problems in Engineering 2022 (September 13, 2022): 1–22. http://dx.doi.org/10.1155/2022/5883404.
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Explosion load studies are an essential part of shield engineering design. This is especially true for explosion-proof plates, which are used in order to reduce the impact of explosions, which have the potential to cause substantial damage to structural elements. The purpose of this study is to detail the explosion phenomenon and the response of sandwich panel structures under explosive loading. The finite element method (FEM) is used to model the dynamic structural response to explosions. Explicit finite element modeling and analysis are performed using ABAQUS CAE software. An air explosion simulation code is used to determine the blast load on the lower skin plate of a test panel on a typical armored personnel vehicle. Structural analysis is carried out with respect to displacement, von-Mises stress, and internal kinetic energy. Three variations of explosive loads are considered in the simulation in order to better compare the responses of the structures. Three different design variants and materials are considered, including honeycomb, stiffener, and corrugated geometric models and mild steel, medium carbon steel, and alloy steel materials. The results provided by this study pave the way toward the development of guidelines for the design of lightweight structural reinforcement elements.
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Bedon, Chiara, and Claudio Amadio. "Passive Control Systems for the Blast Enhancement of Glazing Curtain Walls Under Explosive Loads." Open Civil Engineering Journal 11, no. 1 (June 30, 2017): 396–419. http://dx.doi.org/10.2174/1874149501711010396.
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Glass curtain walls are used in modern buildings as envelopes for wide surfaces due to a multitude of aspects. In glass curtain walls, tensile brittle panels are connected - through mechanical or adhesive joints - with steel frameworks or aluminum bracing systems, and due to the interaction of several structural components, the behaviour of the so assembled system is complex to predict, especially under exceptional loading conditions such as explosive events. In the paper, glazing curtain walls are investigated by means of Finite-Element (FE) numerical simulations, under the effect of air blast pressures of variable intensity. Their typical dynamic behaviour and criticalities under high-strain impact loads are first analyzed. By means of extended nonlinear dynamic FE parametric studies, innovative devices are applied to traditional curtain walls, at their support points, in order to improve their expected dynamic response. Two possible solutions, namely consisting of viscoelastic (VE) or elasto-plastic (PL) dampers, are proposed as passive control systems for the mitigation of maximum effects in the façade components deriving from the incoming blast pressures. As shown, although characterized by specific intrinsic mechanical behaviours, either VE or PL dampers can offer beneficial structural effects. In the first case, major advantages for the façade components derive from the additional flexibility and damping capacities of VE devices. In the latter case, PL dampers introduce additional plastic energy dissipation in the traditional curtain wall assembly, hence allowing preventing severe damage in the glazing components. It is thus expected that the current outcomes could represent a valid background for further experimental validation as well as detailed assessment and optimization of the proposed design concept.
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Temelli, Uğur Emre, Cüneyt Öngören, and Baris Sayin. "Damage assessment of a cement plant partially collapsed depending on various causes." Journal of Structural Engineering & Applied Mechanics 5, no. 2 (June 30, 2022): 62–76. http://dx.doi.org/10.31462/jseam.2022.02062076.
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This study aims at examining the possible causes of the brittle collapse of a tertiary air duct system under vertical loads. Problems related to the design and construction stages were examined. The entire process was illustrated using a tertiary air duct case study in a cement plant. In the plant, the tertiary air duct collapsed without any earthquake, blast, or impact effects. The current study includes a field study, examination of an original/revised design project, and numerical simulation. In the first stage of the study, the existing state of the collapsed system and its compliance with static and mechanical projects were examined. Secondly, a two-dimensional finite element analysis was performed to determine project eligibility. The causes of the system were determined based on the data obtained in the former stages. The results showed that the causes of partial collapse included project errors, construction faults, and project incompatibilities.
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Wei, Ming Shan, Jin Ji Feng, Hai Cao, and Ya Qi Ye. "Test Study on Support Span of Sheet Sandwich Structure of Steel Fiber Concrete." Applied Mechanics and Materials 94-96 (September 2011): 1386–90. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1386.
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The layer structure is a common structural form in the civil air defence. According to the shortage of the structure, a new type of structural form called steel fiber sheet sandwich structure is setup. For studying the influence caused by the support span of this structural form on structural blast-resistant ability, this paper has carried out a group of explosion model tests, which studies the optimal support span of this structure form and the influence on the failure characteristics of structure induced by the change of the support span. The test results show that: the support span of the steel fiber sheet is a very important factor for improving the whole structural blast-resistant ability; the thickness and support span of Steel fiber sheet shall make the steel fiber sheet not to reach the roof surface under the loads of explosion; the whole resistance of sheet sandwich structure in the tests is obviously higher than that of ordinary layer structure.
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Ritchie, Cameron B., Matthew I. Gow, Jeffrey A. Packer, and Amin Heidarpour. "Influence of elevated strain rate on the mechanical properties of hollow structural sections." International Journal of Protective Structures 8, no. 3 (August 7, 2017): 325–51. http://dx.doi.org/10.1177/2041419617721530.
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As protective design engineering becomes more prevalent, cold-formed steel hollow structural sections are often desired design components. As such, it is necessary to understand the behavior of hollow structural sections subject to air-blast loading, including the material response under elevated strain rates. Dynamic tensile tests have hence been performed on subsize tensile coupons taken from the flats and corners of cold-formed rectangular hollow section members. Dynamic yield stresses were obtained at strain rates from 0.1 to 18 s−1, which encompasses and exceeds the range recorded during far-field blast arena testing. The dynamic increase factor was calculated for each data point and synthesized with previous cold-formed rectangular hollow section tests at even higher strain rates (100–1000 s−1). The data set was used to determine Cowper–Symonds and Johnson–Cook parameters. The resulting material models can now be used to determine the strength increase of cold-formed rectangular hollow sections subject to a wide range of impulsive, elevated strain rate loads.
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Semenov, Yu S., E. I. Shumelchik, V. V. Horupakha, S. V. Vashchenko, O. Yu Khudyakov, K. P. Ermolina, I. Yu Semion, and I. V. Chychov. "INTRODUCTION OF DECISION SUPPORT SYSTEMS FOR BLAST SMELTING CONTROL IN THE CONDITIONS OF METALLURGICAL PRODUCTION OF PRJSC "DNIPROVSKYI COKE PLANT"." Fundamental and applied problems of ferrous metallurgy, no. 35 (2021): 78–94. http://dx.doi.org/10.52150/2522-9117-2021-35-78-94.
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The aim of the work is to increase the level of automation of blast furnace production through the development and implementation of new systems to support decision-making on the management of blast furnace smelting in changing technological and fuel conditions. The article presents a description of three decision support systems (DSS) in the mode of an adviser to the technological personnel of blast furnaces, which were implemented by the Iron and Steel Institute or underwent pilot testing as part of the automated control system of the blast furnace shop of the metallurgical production of PrJSC "Dniprovskyi Coke Plant" (Kamianske). The first DSS for managing the thermal state was implemented in 2021, it includes the entire list of information necessary for personnel in a convenient and compact form, generates recommendations in case of technology deviations and, in case of incorrect actions of the personnel, signals the need for correct actions. The main recommendations of the system are to correct the raceway adiabatic flame temperature, coke consumption when its characteristics and ore load change. Using the system allows both reducing the specific coke consumption and preventing unplanned downtime. The second DSS for controlling the distribution of fuel additives over air tuyeres is based on information on thermal loads determined on water-cooled elements of tuyere tools. The main recommendations of the system are to adjust the amount of injected pulverized coal fuel on individual tuyeres in order to ensure a uniform distribution of the raceway adiabatic flame temperature around the circumference of the blast furnace and, as a result, the energy efficiency of blast furnace smelting. The third DSS for adjusting the parameters of the charging mode is based on information from the means of controlling the temperatures of the gas flow above the surface of the charge in the blast furnace. The functioning of this system is based on determining the reference curves for the distribution of the gas flow along the furnace radii, corresponding to the minimum consumption of coke and maximum productivity, and on the search for solutions by direct and iterative optimization methods, which allow, by adjusting the loading parameters, to ensure a rational distribution of charge materials and gas flow in the furnace.
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Anas, S. M., Mehtab Alam, and Mohammad Umair. "Experimental Studies on Blast Performance of Unreinforced Masonry Walls: A state-of-the-art review." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (December 19, 2022): 1791–802. http://dx.doi.org/10.38208/acp.v1.720.
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A large proportion of India’s residential buildings is of unreinforced masonry (URM) and falls under the category of non-engineered structures. URM walls in the residential buildings, customarily constructed from clay bricks or concrete blocks and cut stones, are found to be braced and therefore able to carry some out-of-plane loads produced by wind and earthquake, and survive. However, they are found to be more vulnerable to high air-pressure generated by explosive-induced detonations. Sufficient amount of investigations has been made by engineers to study the effect of brick strength, mortar strength, boundary conditions, wall thickness, and Young’s modulus of masonry on the blast performance of the URM walls. In this paper, available experimental studies on clay-brick and concrete block URM walls subjected to explosive-induced blast loading are briefly reviewed and summarized in tabular form. Studies conducted to improve the blast resistance of the walls using GFRP strips, GFRP rods, and Polyurea coating, and their effect on mid-span deflection, damage, and cracks have also been reviewed. It has been observed that the effect of brick strength and mortar strength on maximum mid-span deflection and damage resistance of the walls is insignificant under higher peak reflected blast pressures (> 2 MPa). Besides, the walls strengthened with the GFRP strips or Polyurea coating performed better with regards to mid-span deflection, damage, and cracking. The influence of Young’s modulus of masonry on the blast response of the walls is found to be more effective in reducing the maximum mid-span deflection. Also, the failure mechanism of the walls is found to be highly dependent upon the peak overpressure, duration of the blast, and support conditions.
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Amadio, Claudio, and Chiara Bedon. "Multiple Dissipative Devices for Blast-Resisting Cable-Supported Glazing Façades." Modelling and Simulation in Engineering 2013 (2013): 1–13. http://dx.doi.org/10.1155/2013/964910.
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The paper analyzes the structural response of a high-level air blast loaded cable-supported façade. Since the glass panels and the cables present a typical brittle behavior and are subjected to elevated tensile stresses when a high-level explosion occurs, multiple dissipative devices are simultaneously introduced in the conventional glazing system to mitigate the maximum effects of the design blast wave. Dynamic analyses are performed using a sophisticated FE-model to describe accurately the response of the façade equipped by dissipative devices. Based on numerical results of previous contributions, viscoelastic spider connectors (VESCs) are introduced in the points of connection between glass panels and pretensioned cables, to replace “rigid” spider connectors commonly used in practice. At the same time, rigid-plastic frictional devices (RPDs) are installed at the top of the bearing cables to mitigate furthermore the bracing system. As a result, due to the combined use of VESCs and RPDs opportunely calibrated, the maximum tensile stresses in the glass panels and in the cables appear strongly reduced. In addition, the proposed devices do not trouble the aesthetics of such transparent structural systems. At last, simple design rules are presented to predict the response of cable-supported façades subjected to high-level dynamic loads and to preliminary estimate the mechanical parameters of combined VESCs and RPDs.
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Ehrgott Jr., John Q., Stephen A. Akers, Jon E. Windham, Denis D. Rickman, and Kent T. Danielson. "The Influence of Soil Parameters on the Impulse and Airblast Overpressure Loading above Surface-Laid and Shallow-Buried Explosives." Shock and Vibration 18, no. 6 (2011): 857–74. http://dx.doi.org/10.1155/2011/672850.
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The dynamic airblast, fragmentation, and soil ejecta loading environments produced by the detonation of surface-laid and shallow-buried mines are major threats to lightweight military vehicles. During the past several years, the US Army has focused considerable attention on developing improved methods for predicting the below-vehicle environment from these threats for use by vehicle/armor analysts; thereby, improving the survivability of these platforms. The US Army Engineer Research and Development Center recently completed the first year of a three-year effort to experimentally and numerically quantify the blast and fragment loading environments on vehicles due to surface and subsurface mine and IED detonations. As part of this research effort, a series of experiments was conducted to quantify the effects of soil parameters on the aboveground blast environments produced by the detonation of aboveground bottom-surface-tangent, buried top-surface-tangent, and shallow-buried 2.3-kg (5-lb) Composition C4 charges. The experiments were conducted using three different well characterized soils; 10.8% air-filled-voids (AFV) silty sand, 5.4% AFV clay, and 29.8% AFV poorly graded sand. The combined aboveground loads due to airblast and soil debris were measured by an impulse measurement device. The near-surface airblast overpressure was quantified by a series of side-on measurements above the charges at one elevation and three radial distances. This paper summarizes and compares the results of the experimental program with emphasis on defining the effect of soil parameters on the aboveground blast environment.
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Librescu, Liviu, Sang-Yong Oh, and Jorg Hohe. "Implication of Nonclassical Effects on Dynamic Response of Sandwich Structures Exposed to Underwater and In-Air Explosions." Journal of Ship Research 51, no. 02 (June 1, 2007): 83–93. http://dx.doi.org/10.5957/jsr.2007.51.2.83.
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A study devoted to the dynamic response of sandwich panels to underwater and in-air explosions is presented. The study is carried out in the context of a geometrically nonlinear model of sandwich structures featuring anisotropic laminated face sheets and a transversely compressible orthotropic core. The unsteady pressure generated by the explosion and acting on the face of the sandwich panel includes the effect of the pressure wave transmission through the core. Its implications on the structural time-histories as corresponding to the underwater and in-air explosions are put into evidence. The effects of the transverse core compressibility on dynamic response are highlighted. In this sense, one of its major implications is the possibility to capture interactively the global and local (wrinkling) dynamic response of the panel. It is shown that implementation of the structural tailoring technique in the face sheets can constitute an important mechanism for enhancing the dynamic load-carrying capacity of sandwich panels when exposed to blast pulses. Effects of the core, the composite architecture of face sheets, orthotropy of the material of the core, geometrical non-linearities, initial geometric imperfection, and the damping ratio are investigated, and their implications for the dynamic response are highlighted. The comprehensive structural model considered in conjunction with the time-dependent loads generated by the underwater and in-air explosions, and the results obtained in this context, are expected to contribute to a better understanding of the response behavior and to be instrumental toward a better design of these structures.
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Grujicic, M., R. Yavari, J. S. Snipes, and S. Ramaswami. "Design optimization of a mine-blast-venting solution for protection of light-tactical-vehicle subjected to shallow-buried underbody mine detonation." Multidiscipline Modeling in Materials and Structures 12, no. 1 (June 13, 2016): 2–32. http://dx.doi.org/10.1108/mmms-11-2014-0058.
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Purpose – The purpose of this paper is computer-aided engineering analysis of the recently proposed side-vent-channel concept for mitigation of the blast-loads resulting from a shallow-buried mine detonated underneath a light tactical vehicle. The concept involves the use of side-vent-channels attached to the V-shaped vehicle underbody, and was motivated by the concepts and principles of operation of the so-called “pulse detonation” rocket engines. By proper shaping of the V-hull and side-vent-channels, venting of supersonically expanding gaseous detonation products is promoted in order to generate a downward thrust on the targeted vehicle. Design/methodology/approach – The utility and the blast-mitigation capacity of this concept were examined in the prior work using computational methods and tools which suffered from some deficiencies related to the proper representation of the mine, soil, and vehicle materials, as well as air/gaseous detonation products. In the present work, an attempt is made to remove some of these deficiencies, and to carry out a bi-objective engineering-optimization analysis of the V-hull and side-vent-channel shape and size for maximum reduction of the momentum transferred to and the maximum acceleration acquired by the targeted vehicle. Findings – Due to the conflicting nature of the two objectives, a set of the Pareto designs was identified, which provide the optimal levels of the trade-off between the two objectives. Originality/value – To the authors’ knowledge, the present work is the first public-domain report of the side-vent-channel blast-mitigation concept.
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Semenov, Yurii S., Yevhen I. Shumelchyk, Viktor V. Horupakha, Igor Y. Semion, Sergii V. Vashchenko, Oleksandr Y. Khudyakov, Igor V. Chychov, Iryna H. Hulina, and Rostyslav H. Zakharov. "Development and Implementation of Decision Support Systems for Blast Smelting Control in the Conditions of PrJSC “Kamet-Steel”." Metals 12, no. 6 (June 8, 2022): 985. http://dx.doi.org/10.3390/met12060985.
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This article presents a description of three decision support systems (DSS) in the mode of an adviser to the technological personnel of blast furnaces (BF), which were implemented by the Iron and Steel Institute of Z.I. Nekrasov (Dnipro, Ukraine) or underwent pilot testing as part of the automated control system of the BF shop of PrJSC “Kamet-steel” (Kamianske, Ukraine). The first DSS for managing the thermal state was implemented in 2021; it includes the entire list of information necessary for personnel in a convenient and compact form, generates recommendations in case of technology deviations, and, in the case of incorrect actions by the personnel, signals the need for correct actions. The main recommendations from the DSS are to correct the raceway adiabatic flame temperature, coke consumption when its characteristics are specified in (indicators of strength and abrasion, fractional composition, humidity, ash and sulfur), and ore load change. Using the system allows both reducing the specific coke consumption and preventing unplanned downtime. The second DSS for controlling the distribution of fuel additives over air tuyeres is based on information on thermal loads determined on water-cooled elements of tuyere tools. The main recommendations from the DSS are to adjust the amount of injected pulverized coal fuel on individual tuyeres in order to ensure a uniform distribution of the raceway adiabatic flame temperature around the circumference of the BF and, as a result, the energy efficiency of BF smelting. The third DSS for adjusting the parameters of the charging mode is based on information from the means of controlling the temperatures of the gas flow above the surface of the charge in the BF. The functioning of this DSS is based on determining the reference curves for the distribution of the gas flow along the BF radii, corresponding to the minimum consumption of coke and maximum productivity, and on the search for solutions by direct and iterative optimization methods, which allow one, by adjusting the charging parameters, to ensure a rational distribution of charge materials and gas flow in the BF.
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Augusto, A. S., F. B. Mendonça, G. S. Urgessa, and K. Iha. "Finite Element Analysis of Experimentally Tested Concrete Slabs Subjected to Airblast." Defence Science Journal 71, no. 5 (September 2, 2021): 630–38. http://dx.doi.org/10.14429/dsj.71.15576.
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Since the last century, concrete has been used to protect structures against intentional or accidental detonation of explosives. Recently, as concerns about terrorist activities and accidents in plants using explosives increase worldwide, the study of the behaviour of this type of material and any civil or military structure under the influence of explosions has increased. Among the lethal effects of explosive devices, which cause greater loads in structural elements is the airblast effect. For this reason, this paper presents a series of airblast finite element (FEM) simulations developed in Abaqus/Explicit®. To validate the computational method, such simulations are geometrically and structurally kept similar to full-scale tests conducted in a blast test area of the Science and Technology Aerospace Department (Brazilian Air Force). Both simulations and tests consisted of seven reinforced concrete slabs with compressive strengths of about 40 to 60 MPa, variable steel reinforcement areas, slab dimensions measuring 1×1 m, and subjected to 2.7 kg of non-confined plastic bonded explosive. The results demonstrated that FEM simulations can predict the rupture of the tested slabs and how the effect occurs, showing a valid method to investigating the response of RC slabs when compared to expensive field tests. Differences in displacements were observed between the results of FEM simulations and blast field tests, mainly caused by the sensitivity of the case studied, limits of computational capacity, and intrinsic variations in the materials and sensors used in the field tests. However, these differences showed an order of magnitude compatible with the safety coefficients used with RC, demonstrating that the method can be used for the design of RC slabs under the effect of airblast.
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Bazhenova, Olga, Sophia Bazhenova, Marat Bazhenov, Saak Ambaryan, and Mikhail Gleyzer. "Flow properties of finely dispersed binder." MATEC Web of Conferences 265 (2019): 01015. http://dx.doi.org/10.1051/matecconf/201926501015.
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This article contains information about strengthening the under-ground parts of buildings and restoration of their bearing capacity, along with solutions of urea-formaldehyde resin and solutions based on sodium silicate (which have a number of significant drawbacks, such as short-lived strengthening, low strength of reinforced soil (0.1-0.5 MPa), brittle destruction under dynamic loads, environmental pollution), using impregnation compositions based on fine mineral binders. This compositions, with the name «Mikrodur», are obtained on the basis of air separation of Portland cement CEM I 52.5 (PC D0 M600) and fine-divided blast furnace slag. The method of preparation of suspension on the basis of finely dispersed binder is considered. The main characteristics determining the finely dispersed binder suspension, such as viscosity and stability of the injectable suspension (sedimentation), are established. It is proved that the indexes of viscosity and stability of solutions depend on the method of their preparation, water/binding ratio and chemical admixtures. A variety of finely dispersed binders grades on mineral composition allows providing ground, stone and concrete structures of underground constructions stabilization taking into account various requirements: strength enhancement and anti-filtration properties of the strengthened masses, their resistance to various aggressive influences, the possibility of hardening in conditions of negative temperature, acceleration of a strength enhancement.
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Stewart, Mark G., Michael D. Netherton, and Hayden Baldacchino. "Observed airblast variability and model error from repeatable explosive field trials." International Journal of Protective Structures 11, no. 2 (August 26, 2019): 235–57. http://dx.doi.org/10.1177/2041419619871305.
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Explosive field trials have been conducted to measure the peak incident pressure, impulse and time of positive phase duration following the detonation of 15 different masses of the Plastic Explosive No #4. A novel aspect of these field trials was the repeatability of tests. Eight pressure gauges collected data during each blast, and at each scaled distance. In all, 4 blasts were conducted for each scaled distance (i.e. up to 32 measurements recorded for each scaled distance) – 60 blasts were fired in total. Consequently, this repeatability of testing allowed the mean and variance of blast pressure–time histories to be quantified, with a view to better characterise the variability of a blast itself and model error variability. This article describes the explosive field trials, and the statistical analysis of blast load variability and model error for peak incident pressure, impulse and time of positive phase duration. It was found that the mean model error is close to unity with a coefficient of variation of up to 0.15 for pressure and 0.21 for impulse. The lognormal probability distribution best fits the model error data. The probabilistic models derived from these tests can be used for a variety of structural engineering applications, such as calculating reliability-based design load or partial safety factors for explosive blast loading, and estimating the probability of damage and casualties for infrastructure subject to explosive blast loading. This is illustrated for a terrorist explosive scenario involving a spherical free-air burst, where the damage modes of interest are breaching and spalling of a concrete slab. It was found that the variability of charge mass, range and model error have a significant effect on reliability-based design.
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Hu, Zhi Jian, and Chao Liu. "Blast Loads on Concrete Bridges." Advanced Materials Research 217-218 (March 2011): 445–50. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.445.
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Nowadays few current studies on blast effects are executed with real bridge structures for economic and social reasons. This paper analyzes the blast loadings on concrete bridges and offers five characteristics: uncertainty, significant structural response, mechanic differences, rapid overpressure decay, and confinement effects. Then with the further study for blast loads fundamentals and real bridge inspection, the damage forms for concrete bridges under blast loadings have been obtained, i.e. localized damage are the main structural damages and fragmentation loads can be neglected when explosions detonated above deck. Furthermore, due to the collapse or fallen of the structural components or segments secondary damages, like collisions and restraining blocks destruction, must be kept an eye on.
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Xiao, Li, and Wen Zhong Qu. "Damage Analysis for Steel Frames under Explosive Loads." Advanced Materials Research 243-249 (May 2011): 5177–81. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.5177.
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In this paper, a series of inelastic transient analysis of steel frame structures under blast loads are numerically performed. Considering the coupling actions of detonator, gases and structure, Arbitrary Lagrangian Eulerian ALE method which is suitable for large deformation systems is applied. In order to capture the effect of explosion load on members, a rate-dependent stress–strain model is used to model the material response of the affected members. The dynamic response and the structural damage of steel frame under blast loading are investigated. The damage pattern of steel frame to blast loads is studied. The results show that the permanent deformation, local buckling, and plastification reduce the resistance of the frame. The affected members may trigger the overall stability of the frame. The damage degree is related to the amount and position of explosives, shape and resistance of the building etc. The damage of the low-story columns and beams may make the structure unstable. The load might not be large enough, the damage to the entire frame may be severe, and it may cause structure collapse.
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Wang, Hai Jun, Yong Yao, Zhao Qiang Zhang, Xiao Pan Yang, and Yu Ping Zhu. "Numerical Simulation on Embedded Steel Frame Concrete Blast Wall Resisting Air Shock Wave." Applied Mechanics and Materials 548-549 (April 2014): 1763–67. http://dx.doi.org/10.4028/www.scientific.net/amm.548-549.1763.
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Embedded steel frame concrete blast walls can effectively counteract and dissipation the air-blast wave of the explosion. By contrast widely recognized air-blast wave empirical formula to verify the feasibility of the method of explosion load simplify model numerical simulation calculate the shock wave problems by using the explicit finite element software ANSYS/LS-DYNA and keywords *LOAD_BLAST. Obtained, The results of simplified explosion shock wave load by *load_blast have small difference with the actual explosion model; The destruction of the wall are mainly shear and brittle failure; The ability of Embedded steel frame blast wall resist air-blast wave significantly greater than other wall.
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Mynarzová, Lucie, and Miroslav Mynarz. "Study of the Effects of Transient Load on Envelope Structure." Applied Mechanics and Materials 470 (December 2013): 335–39. http://dx.doi.org/10.4028/www.scientific.net/amm.470.335.
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The contribution compares the response of envelope of chosen structure to the effects of transient load. The load was caused by air blast wave due to deflagration of methane-air mixture. The paper deals with interaction of incident blast wave and envelope structure. Considering blast courses obtained from experiments, two simplified models of load were developed. Load, defined by both load functions, was applied to 3D numerical model of the structure. Calculated result values of deflections of wall elements were compared to experimentally obtained deflections.
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Yuan, Xiao Jun, Li Chen, Jian Hua Wu, and Jing Xin Tang. "Numerical Simulation of Masonry Walls Subjected to Blast Loads." Advanced Materials Research 461 (February 2012): 93–96. http://dx.doi.org/10.4028/www.scientific.net/amr.461.93.
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Much effort has been devoted to studying the blast properties of masonry infilled panels due to recent increasing accidental blast events. In this paper, the blast properties of the masonry infilled walls were analyzed with the finite element program LS-DYNA by the way of distinctive consideration of the bricks and mortar material in contrast to the experimental data. The numerical results have a good agreement with experimental data. The reliability and efficiency of this method in predicting the dynamic responses of masonry walls to blast loads was proven.