scholarly journals Probabilistic models for blast parameters and fragility estimates of steel columns subject to blast loads

2020 ◽  
Vol 222 ◽  
pp. 110944
Author(s):  
Karandeep Singh ◽  
Paolo Gardoni ◽  
Flavio Stochino
Keyword(s):  
Probabilistic Models ◽  
Blast Loads ◽  
Steel Columns ◽  
Blast Parameters

Dynamic Response and Failure Mode Analysis on Light-Weight Steel Columns under Blast Loads

2012 ◽  
Vol 166-169 ◽  
pp. 1489-1497 ◽  
Author(s):  
Shi Yan ◽  
Lei Liu ◽  
Peng Li ◽  
Zhi Qiang Xin ◽  
Bao Xin Qi
Keyword(s):  
Dynamic Response ◽  
Failure Mode ◽  
Failure Modes ◽  
Shear Failure ◽  
Mode Analysis ◽  
Material Strength ◽  
Light Weight ◽  
Blast Loads ◽  
Element Analysis ◽  
Steel Columns

The dynamic response and failure mode of light-weight steel columns under blast loads were studied in this paper by using nonlinear finite element analysis (FEA) software ANSYS/ LS-DYNA, aiming to develop the degree and modes of the excessive plastic deformation during failures of the columns under diverse parameters. The damaged columns with initial blast-induced deformation may evidently influence vertical stability of light-weight steel frame structures. During the numerical simulation, the element of three dimensional solid SOLID164 was used, and the strain rate effect on material strength was included in the material model with Plastic-Kinematic (MAT-03). The main parameters included in the analysis were boundary conditions, scaled distances of explosions, and the vertical compressive load ratios applied on tops of the columns. The results showed that the column with both two fixed ends was the most beneficial to resist blast shock wave, the horizontal displacement at the middle span of the columns were obviously decreasing as increasing of the scaled distances of the explosion, and the axial compression ratio only significantly influenced the column with a sliding end. The failure modes of the developed columns may be summarized as bending failure, direct shear failure, and bending shear combination failure.

Damage evaluation of H-section steel columns under impulsive blast loads via gene expression programming

2020 ◽  
Vol 219 ◽  
pp. 110909 ◽  
Author(s):  
Mohammad Momeni ◽  
Mohammad Ali Hadianfard ◽  
Chiara Bedon ◽  
Abdolhossein Baghlani
Keyword(s):  
Gene Expression ◽  
Gene Expression Programming ◽  
Damage Evaluation ◽  
Blast Loads ◽  
Steel Columns

scholarly journals Behaviour and Failure of Steel Columns Subjected to Blast Loads: Numerical Study and Analytical Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Haitham Al-Thairy
Keyword(s):  
Parametric Study ◽  
Analytical Approach ◽  
Numerical Study ◽  
Slenderness Ratio ◽  
Compressive Force ◽  
Design Procedure ◽  
Blast Load ◽  
Blast Loads ◽  
Steel Columns ◽  
Failure Patterns

The main objective of this study is the numerical simulation of the behaviour and failure patterns of steel columns under blast loads using the dynamic finite element package ABAQUS/Explicit. A numerical model is suggested and validated against published experimental tests on full-scale wide-flange steel columns subjected to dynamic blast loads under constant axial compressive force. Afterwards, the validated model is used to investigate the effect of important parameters on the behaviour and failure patterns of steel columns under blast pressure through an extensive parametric study. The parameters include the blast impulse, the blast energy, the blast load, the blast duration, the column boundary condition, the column slenderness ratio, and the blast direction. The conclusions extracted from this parametric study may be used to develop a thorough understanding of the behaviour and failure of steel columns subjected to blast load which, in turn, could lead to a more accurate practical design procedure. The study also presents derivations and validations of a proposed analytical approach to calculate the critical blast impulse at which a steel column losses its global stability. Comparison between the critical impulse-axial force curves obtained from the proposed equation and that extracted from numerical simulations indicates the validity and feasibility of the proposed equation.

Research on Impact Response and Failure Modes of H Section Steel Frame Columns Subject to Blast Loads

2012 ◽  
Vol 204-208 ◽  
pp. 3094-3098
Author(s):  
Yun Fei Liu ◽  
Hong Gang Lei
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Plate Thickness ◽  
Steel Frame ◽  
Impact Response ◽  
Blast Loads ◽  
Steel Columns ◽  
Steel Column ◽  
Impulse Load ◽  
The Impact

Using finite software ANSYS LS/DYNA for simulating the impact response and failure modes of H section steel frame columns subject to blast loads，and loading different load conditions, changing column boundary conditions and web plate thickness. Conclusion: the failure model of steel columns changes with the change of load form,steel columns will be easy to occur shear failure in the end by the dynamic load, and the flange will be easy to occur bucking failure in local by impulse load; In the case of same size and web thickness, increase the web thickness can reduce the deformation of column effectively, improve the capability of H section steel column resist the blast load.

Assessment of a coupled approach to determine the stress caused by gun blast loads

2019 ◽  
pp. 154851291989233
Author(s):  
Emiliano Costa
Keyword(s):  
Free Field ◽  
Numerical Procedure ◽  
Structural Response ◽  
General Purpose ◽  
Blast Loads ◽  
Design Procedures ◽  
Blast Design ◽  
Field Peak ◽  
Blast Parameters ◽  
Asymmetric Shape

This paper aims at assessing a custom numerical procedure built to predict the level of stress in the structural components and equipment in proximity of a cannon-like weapon system when firing. In such a blast scenario, the structures adjacent to a gun may undergo sudden and unwanted damages, since they are commonly subjected to the blast load due to the impingement and propagation of the shock waves expanding from the weapon muzzle. The proposed procedure pertains the coupled use of an in-house developed tool (GUNWave3D) based on the power-law scaling technique and a general-purpose commercial fast dynamic solver to compute the structural response of the loaded components. The in-house tool, in particular, allows one to rapidly calculate the blast parameters over the surfaces of the items of interest in the function of the weapon characteristics and launch conditions, also accounting for the asymmetric shape characterizing the gun blast wave. Taking as reference the numerical free field peak overpressure profiles of a 30 mm gun, whose blast quantities were already validated in a previously published work, the final stage of the assessment was accomplished. Such an estimation consists of the comparison between the structural stresses calculated using the blast loads predicted through the in-house tool and those computed adopting the free spherical air blast of the tri-nitro-toluene model. This operation has the objective to quantify the discrepancy between the computational results of two Lagrangian techniques that can be alternatively adopted in industrial gun blast design procedures and methodologies.

Enhancement of blast wave parameters due to shock focusing from multiple simultaneously detonated charges

2021 ◽  
pp. 204141962110333
Author(s):  
Amir Zaghloul ◽  
Alex Remennikov ◽  
Brian Uy
Keyword(s):  
Blast Wave ◽  
Blast Waves ◽  
Terrorist Attacks ◽  
Blast Loads ◽  
Single Charge ◽  
Shock Focusing ◽  
Approximate Methods ◽  
The Past ◽  
Wave Parameters ◽  
Blast Parameters

With the increase of terrorist attacks over the past decades, many engineering societies have started issuing design guides to calculate blast loads on structures. While such guides can be successfully used to assess blast loads due to single detonations, the effects of multiple detonations are often overlooked. In this research, the enhancement in blast parameters resulting from simultaneously detonating multiple charges is investigated, emphasising the interaction of blast waves with narrow targets. A parametric CFD study using the finite volume code Viper::Blast was performed where the number of charges, their arrangement, and the scaled stand-off distances were changed. It is found that, when detonated simultaneously, multiple charges return much higher pressure and impulse values compared to an equivalent single charge. Moreover, an arced arrangement of multiple charges is more efficient than a flat arrangement in enhancing blast wave parameters. Such enhancement is beneficial in scenarios involving demolition. Approximate methods to compute blast wave parameters from multiple simultaneously detonated spherical charges are presented in this study, where pressure and impulse from multiple charges can be computed by only knowing the parameters resulting from an equivalent single charge.

scholarly journals An Efficient Reliability-Based Approach for Evaluating Safe Scaled Distance of Steel Columns under Dynamic Blast Loads

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 606
Author(s):  
Mohammad Momeni ◽  
Chiara Bedon ◽  
Mohammad Ali Hadianfard ◽  
Abdolhossein Baghlani
Keyword(s):  
Structural Reliability ◽  
Progressive Collapse ◽  
Structural Members ◽  
Blast Loads ◽  
Explicit Finite Element ◽  
Scaled Distance ◽  
Steel Columns ◽  
Damage Probability ◽  
Critical Issues ◽  
Building Load

Damage to building load-bearing members (especially columns) under explosions and impact are critical issues for structures, given that they may cause a progressive collapse and remarkably increase the number of potential victims. One of the best ways to deal with this issue is to provide values of safe protective distance (SPD) for the structural members to verify, so that the amount of damage (probability of exceedance low damage) cannot exceed a specified target. Such an approach takes the form of the so-called safe scaled distance (SSD), which can be calculated for general structural members but requires dedicated and expensive studies. This paper presents an improved calculation method, based on structural reliability analysis, to evaluate the minimum SSD for steel columns under dynamic blast loads. An explicit finite element (FE) approach is used with the Monte Carlo simulation (MCS) method to obtain the SSD, as a result of damage probability. The uncertainties associated with blast and material properties are considered using statistical distributions. A parametric study is thus carried out to obtain curves of probability of low damage for a range of H-shaped steel columns with different size and boundaries. Finally, SSD values are detected and used as an extensive databank to propose a practical empirical formulation for evaluating the SSD of blast loaded steel columns with good level of accuracy and high calculation efficiency.

Management of Economics and State "Bottom"

2020 ◽  
Vol 17 (6) ◽  
pp. 76-91
Author(s):  
E. D. Solozhentsev
Keyword(s):  
Quality Of Life ◽  
Artificial Intelligence ◽  
Probabilistic Models ◽  
Human Life ◽  
Special Software ◽  
Human Quality ◽  
Relationship Of ◽  
The Relationship

The scientific problem of economics “Managing the quality of human life” is formulated on the basis of artificial intelligence, algebra of logic and logical-probabilistic calculus. Managing the quality of human life is represented by managing the processes of his treatment, training and decision making. Events in these processes and the corresponding logical variables relate to the behavior of a person, other persons and infrastructure. The processes of the quality of human life are modeled, analyzed and managed with the participation of the person himself. Scenarios and structural, logical and probabilistic models of managing the quality of human life are given. Special software for quality management is described. The relationship of human quality of life and the digital economy is examined. We consider the role of public opinion in the management of the “bottom” based on the synthesis of many studies on the management of the economics and the state. The bottom management is also feedback from the top management.

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