Prediction of Initial and Striking Velocity of Primary Fragments from Cased Spherical Explosive inside Steel Cubical Structure (original) (raw)
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International Journal of Impact Engineering, 2017
Detonations of nitromethane spherical charges have been carried out to study close-in blast loading of steel plates and the effectiveness of several protective solutions. Three types of bare steel plates, namely mild steel, high-strength steel, and stainless steel were subjected to explosive blast loading. Steel plates of the same type with polyurea coating and composite covers were also subjected to localized blast loading. During an explosive field trial, the blast pressures and displacements of steel plates were measured. Additionally, loading of steel plates by the impinging detonation products was captured by high-speed video recordings. This experimental program has produced results which can be used to calibrate numerical models and to refine the simplified models for predicting blast loads and response of structural elements due to close-in detonations. The effectiveness of polyurea coating for enhancing blast protection of steel plated structures is discussed. The engineering-level model for predicting the blast impact impulse of the detonation gases from the charges in close proximity from the target is introduced and validated using the experimental results obtained during the course of the explosive trials.
International Journal of Impact Engineering, 2017
Detonations of nitromethane spherical charges have been carried out to study close-in blast loading of steel plates and the effectiveness of several protective solutions. Three types of bare steel plates, namely mild steel, high-strength steel, and stainless steel were subjected to explosive blast loading. Steel plates of the same type with polyurea coating and composite covers were also subjected to localized blast loading. During an explosive field trial, the blast pressures and displacements of steel plates were measured. Additionally, loading of steel plates by the impinging detonation products was captured by high-speed video recordings. This experimental program has produced results which can be used to calibrate numerical models and to refine the simplified models for predicting blast loads and response of structural elements due to close-in detonations. The effectiveness of polyurea coating for enhancing blast protection of steel plated structures is discussed. The engineering-level model for predicting the blast impact impulse of the detonation gases from the charges in close proximity from the target is introduced and validated using the experimental results obtained during the course of the explosive trials.
International Journal of Mechanical Engineering and Robotics Research, 2019
The increasing threat of a blast explosion from high explosive devices, such as trinitro-toluene (TNT) encapsulated by a steel casing shell, makes the study of the blast phenomenon more important. In this paper, a study of the blast phenomenon due to TNT was studied. Both experimental and numerical analyses were done. The explosive system comprises 80 kg of TNT encapsulated by a steel casing shell, with the total weight of the device being 250 kg. Experimental results showed that the blast velocity was found to be 827 m/s, while the shrapnel velocity was 802 m/s. Numerical analysis using LS-DYNA simulated the explosion sequences in detail and predicted the maximum velocity of the shrapnel.
Detonations of nitromethane spherical charges have been carried out to study near-field blast loading of steel plates and the effectiveness of several protective solutions. Three types of bare steel plates, namely mild steel, high-strength steel, and stainless steel were subjected to explosive blast loading. Steel plates of the same type with polyurea coating and composite covers were also subjected to localised blast loading. During an explosive field trial, the blast pressures and displacements of steel plates were measured. Additionally, loading of steel plates by the impinging detonation products was captured by high-speed video recordings. This experimental program has produced results which can be used to calibrate numerical models and to refine the simplified models for predicting blast loads and response of structural elements due to close-in detonations. The effectiveness of polyurea coatings and other solutions for enhancing blast protection of vehicle and ship structures is discussed.
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2012
The Klotz Group (KG), an mtemational group of experts on explosion safety, investigates the debris throw hazard associated with the accidental detonation of ammunition in reinforced concrete (RC-) structures. Experiments are combined with engineering models but also with results of advanced computational modeling, which is the topie of this paper. EMI and TNO are establishing a three step approach to analyze the explosion phenomena of single and multiple bare and cased charges in a RC structure. In the first step the blast loading and gas pressure is computed including the venting process. A cubicle RC structure was modeled in 3D to capture the correct structural failure mode and venting process, from the coupled fluid-structure interaction simulations. The second step consists of internal trajectory predictions using fragmentation matrices based on arena test data together with hydrocodc simulations for deeper understanding the jetting effects of casing remainders within the concre...
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Procedia Engineering, 2017
With the increase in terrorist attacks in recent years, the effects of explosions on building become highly topical. In this regard, the paper deals with the analysis of blast loaded steel structures. When a blast loaded structure is analysed, as known, two major design issues and scientific challenges have to be approached and solved. The first issue derives from the analysis and description of the input dynamic load (time-pressure wave), being dependent on the type of explosion and explosive, while the second issue is related to the analysis of the actual dynamic response of the structure under impact. As such, real field blast tests using the so called ANFO explosives are first presented. The examined constructional system consists of steel rolled beams with two different type of cross sections (HEB100 and IPE120). The actual experimental observations are then assessed and compared with both SDOF and FE models carried out in ABAQUS. In doing so, the actual shape (i.e. decaying path for the pressure load) of the experimental blast wave is used, together with two further approximations for its description. The comparative calculations are then proposed for selected control points, in terms of mechanical and kinematic quantities (i.e. displacements, accelerations and strains). A critical discussion of the so collected comparative results is hence proposed.
Modelling and Testing of Blast Effect On the Structures
IOP Conference Series: Earth and Environmental Science
As a blasting agent in the blasting and mining engineering, has been using one of so called new generation of explosives which offer greater flexibility in their range and application, and such explosive is ANFO. It is type of explosive consists of an oxidiser and a fuel (ammonium nitrate and fuel oil). One of such ANFO explosives which are industrially made in Slovakia is POLONIT. The explosive is a mixture of ammonium nitrate, methyl esters of higher fatty acids, vegetable oil and red dye. The paper deals with the analysis of structure subjected to the blast load created by the explosion of POLONIT charge. First part of paper is describing behaviour and characteristic of blast wave generated from the blast (detonation characteristics, physical characteristics, time-history diagram etc.) and the second part presents the behaviour of such loaded structures, because of the analysis of such dynamical loaded structure is required knowing the parameters of blast wave, its effect on structure and the tools for the solution of dynamic analysis. The real field tests of three different weight of charges and two different structures were done. The explosive POLONIT was used together with 25 g of ignition explosive PLNp10. Analytical and numerical model of blast loaded structure is compared with the results obtained from the field tests (is compared with the corresponding experimental accelerations). For the modelling structures were approximated as a one-degree system of freedom (SDOF), where the blast wave was estimated with linear decay and exponential decay using positive and negative phase of blast wave. Numerical solution of the steel beam dynamic response was performed via FEM (Finite Element Method) using standard software Visual FEA.
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Proceedings of the 2nd Conference on European Computing Conference, 2008
This paper is based on non-linear finite element analysis of the effects of the blast wave on structures, caused by the detonation of explosive materials. Dynamic response of a pipeline subjected to the shock wave produced by the detonation of high explosive materials is presented in this paper. Coupled Euler and Lagrange formulation are used in the finite element analysis of such problems to accurately represent the detonation phenomenon. Preliminary results allow for detailed analysis of the blast wave propagation and its influence on the pipeline.