scholarly journals Research on Damage Assessment of Concrete-Filled Steel Tubular Column Subjected to Near-Field Blast Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Ying Cui ◽  
Meimei Song ◽  
Zhan Qu ◽  
Shanshan Sun ◽  
Junhai Zhao
Keyword(s):  
Cross Section ◽  
Damage Assessment ◽  
Near Field ◽  
Blast Loading ◽  
Positive Pressure ◽  
Damage Evaluation ◽  
Pressure Impulse ◽  
Double Skin ◽  
Cfst Columns ◽  
Peak Pressures

Concrete-filled steel tubular (CFST) columns are widely used in engineering structures, and they have many different cross section types. Among these, normal solid sections and concrete-filled double-skin steel tubular sections are often used. Although many studies have been conducted on CFST columns with these two section types, no studies have been conducted on their damage assessment under blast loading. In this study, experimental analysis and a numerical simulation method were integrated to evaluate the responses and assess the damage of two concrete-filled steel tubular (CFST) columns with different cross sections subjected to near-field blast loading. The results showed that for a scaled distance of 0.14 m/kg1/3, plastic bending deformation occurred on the surfaces of the two CFST columns facing the explosive. The antiexplosion performance of the normal solid-section (NSS) CFST column was better than that of the concrete-filled double-skin steel tubular (CFDST) column. The explosion centre was set at the same height as the middle of column, and the distributions of the peak pressure values of the two columns were similar: the peak pressures at the middle points of the columns were the greatest, and the peak pressures at the bottom were higher than those at the top. With the analysis of the duration of the positive pressure, the damage at the middle was the most severe when subjected to blast loading. Using pressure-impulse damage theory and the validated numerical simulations, two pressure-impulse damage evaluation curves for NSS and CFDST columns were established separately by analysing the experimental and simulation data. Finally, based on the two pressure-impulse damage evaluation curves, the two pressure-impulse damage criteria for these two different fixed-end CFST columns were defined based on the deflection of the surfaces facing the explosives. Furthermore, the mathematical formulae for the two different column types were established to generate pressure-impulse diagrams. With the established formulae, the damage of the CFST columns with these two cross section types can be evaluated. Damage to other similar CFST columns with different cross section types due to near-field blast loading can also be evaluated by this method.

scholarly journals Research on Damage Assessment of Buried Standard and Carbon-Fibre-Reinforced Polymer Petroleum Pipeline Subjected to Shallow Buried Blast Loading in Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Ying Cui ◽  
Jun Fang ◽  
Zhan Qu ◽  
Meimei Song ◽  
Junhai Zhao
Keyword(s):  
Carbon Fibre ◽  
Damage Assessment ◽  
Blast Loading ◽  
Critical Ratio ◽  
Damage Evaluation ◽  
Pressure Impulse ◽  
Reinforced Polymer ◽  
Petroleum Pipelines ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Buried petroleum pipelines may encounter threats from blast loading due to terrorist attacks, accidental explosions, and artificial blasting during in-progress construction. Carbon-fibre-reinforced polymer (CFRP) is often used for the repair and reinforcement of buried petroleum pipelines. It is meaningful and necessary to distinguish the different responses and establish an effective damage assessment method for standard petroleum pipelines and CFRP-supported petroleum pipelines buried in soil under blast loading. In this study, under fixed end constraints, experimental analysis and numerical simulations were combined to assess the damage of a standard petroleum pipeline and a CFRP petroleum pipeline buried in soil under blast loading. The results showed that, for a scaled distance of 0.19 m/kg1/3, plastic deformation occurred on the surfaces of the two pipelines facing the explosive. The antiexplosion performance of the CFRP pipeline was better than that of the standard pipeline, and the CFRP sheets had a positive effect on the protection of the buried petroleum pipeline during the buried blast loading. Furthermore, based on pressure-impulse damage theory and with consideration of the feasibility under real circumstances, two pressure-impulse damage evaluation curves for standard and CFRP pipelines facing explosive loads were established separately based on a new critical ratio of the dent depth and length. Finally, based on the two pressure-impulse damage evaluation curves and the new critical ratio, two pressure-impulse damage criteria for these two buried petroleum pipelines were defined. Moreover, with the two pressure-impulse damage evaluation curves, mathematical formulae for the two different buried petroleum pipelines were established to generate pressure-impulse diagrams. With the established formulae, the damage to the standard buried pipeline and the CFRP pipeline could be evaluated effectively. Damage to other similar standard pipelines or CFRP pipelines buried in soil with different design parameters due to shallow buried blast loading could also be evaluated using this method.

Single-Degree-of-Freedom Based Pressure-Impulse Diagrams for Blast Damage Assessment

2014 ◽  
Vol 567 ◽  
pp. 499-504 ◽  
Author(s):  
Zubair Imam Syed ◽  
Mohd Shahir Liew ◽  
Muhammad Hasibul Hasan ◽  
Srikanth Venkatesan
Keyword(s):  
Damage Assessment ◽  
Structural Response ◽  
Blast Loading ◽  
Computational Effort ◽  
Degree Of Freedom ◽  
Negative Phase ◽  
Single Degree Of Freedom ◽  
Pressure Impulse ◽  
Single Degree ◽  
Structural Resistance

Pressure-impulse (P-I) diagrams, which relates damage with both impulse and pressure, are widely used in the design and damage assessment of structural elements under blast loading. Among many methods of deriving P-I diagrams, single degree of freedom (SDOF) models are widely used to develop P-I diagrams for damage assessment of structural members exposed to blast loading. The popularity of the SDOF method in structural response calculation in its simplicity and cost-effective approach that requires limited input data and less computational effort. The SDOF model gives reasonably good results if the response mode shape is representative of the real behaviour. Pressure-impulse diagrams based on SDOF models are derived based on idealised structural resistance functions and the effect of few of the parameters related to structural response and blast loading are ignored. Effects of idealisation of resistance function, inclusion of damping and load rise time on P-I diagrams constructed from SDOF models have been investigated in this study. In idealisation of load, the negative phase of the blast pressure pulse is ignored in SDOF analysis. The effect of this simplification has also been explored. Matrix Laboratory (MATLAB) codes were developed for response calculation of the SDOF system and for repeated analyses of the SDOF models to construct the P-I diagrams. Resistance functions were found to have significant effect on the P-I diagrams were observed. Inclusion of negative phase was found to have notable impact of the shape of P-I diagrams in the dynamic zone.

Performance of Simplified Damage Assessment Tools for Reinforced Concrete Panels under Blast Loading

2013 ◽  
Vol 594-595 ◽  
pp. 492-497
Author(s):  
Zubair Imam Syed ◽  
Mohd Shahir Liew ◽  
Priyan Mendis
Keyword(s):  
Reinforced Concrete ◽  
Damage Assessment ◽  
Near Field ◽  
Blast Loading ◽  
Assessment Methods ◽  
Assessment Tools ◽  
Charge Weight ◽  
Far Field ◽  
Concrete Panels ◽  
Blast Effects

Pressure-impulse (P-I) and charge weight-distance (CW-D) diagrams are widely used as quick damage assessment tools for reinforced concrete (RC) elements exposed to blast loading. Depending on the loading and element properties, the blast loading can induce different patterns of response and damage. Appropriate application of different simplified damage assessment tools for both far-field and near-field blast effects can be significantly challenging. This paper presents the comparison of the performances of two commonly used simplified damage assessment methods for RC elements exposed to explosive loading. Different aspects of the simplified damage assessment methods related to their construction and application for damage assessment are investigated. Some specific limitations of construction and use of P-I and CW-D diagrams are explored. Suitability of P-I diagrams for far-field and near-field blast effects is also explored. P-I diagrams are found to provide misleading damage assessment when applied for near-field blast effects.

scholarly journals Numerical damage evaluation of perforated steel columns subjected to blast loading

2021 ◽  
Author(s):  
Mahmoud T. Nawar ◽  
Ibrahim T. Arafa ◽  
Osama M. Elhosseiny
Keyword(s):  
Blast Loading ◽  
Damage Evaluation ◽  
Steel Columns

Heat Transfer in a Supersonic Parallel Diffuser

1965 ◽  
Vol 7 (1) ◽  
pp. 1-7 ◽  
Author(s):  
P. J. Baker
Keyword(s):  
Heat Transfer ◽  
Pressure Gradient ◽  
Cross Section ◽  
Static Pressure ◽  
Positive Pressure ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Pipe Flows ◽  
Pressure Distributions ◽  
The Mean

This paper presents the results of heat transfer measurements taken on a two-dimensional supersonic parallel diffuser. The wall static pressure distributions and the corresponding heat transfer coefficients and fluxes have been measured for a range of initial total pressures. The effects of varying the area of the diffuser cross-section for the same upstream generating nozzle have also been studied. Mach number profiles measured at sections along the diffuser show that in the presence of shock waves and a positive pressure gradient the flow is very much underdeveloped. In general, the mean level of heat transfer is found to be much greater than that predicted by conventional empirical equations for subsonic pipe flows with zero pressure gradient. Further, on comparison between normal and oblique shock diffusion the former is found to give the higher level of heat transfer.

scholarly journals EFFICIENT SIMULATION TOOL TO CHARACTERIZE THE RADAR CROSS SECTION OF A PEDESTRIAN IN NEAR FIELD

2020 ◽  
Vol 100 ◽  
pp. 145-159
Author(s):  
Giovanni Manfredi ◽  
Paola Russo ◽  
Alfredo De Leo ◽  
Graziano Cerri
Keyword(s):  
Cross Section ◽  
Near Field ◽  
Radar Cross Section ◽  
Simulation Tool ◽  
Efficient Simulation

scholarly journals Brief communication: simple-INSYDE, development of a new tool for flood damage evaluation from an existing synthetic model

2020 ◽  
Author(s):  
Marta Galliani ◽  
Daniela Molinari ◽  
Francesco Ballio
Keyword(s):  
Damage Assessment ◽  
Direct Analysis ◽  
Flood Damage ◽  
Damage Evaluation ◽  
Explanatory Variables ◽  
Synthetic Model ◽  
Flood Damage Assessment ◽  
Correct Implementation

Abstract. INSYDE is a multi-variable, synthetic model for flood damage assessment to dwellings. The analysis and use of this model highlighted some weaknesses, linked to its complexity, that can undermine its usability and correct implementation. This study proposes a simplified version of INSYDE which maintains its multi-variable and synthetic nature, but has simpler mathematical formulations permitting an easier use and a direct analysis of the relation between damage and its explanatory variables.

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