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.

scholarly journals PARAMETRIC STUDY ON THE FIRE RESISTANCE OF STEEL COLUMNS WITH COLD-FORMED LIPPED CHANNEL SECTIONS

2016 ◽  
Author(s):  
Flávio Arrais ◽  
Nuno Lopes ◽  
Paulo Vila Real
Keyword(s):  
Cross Sections ◽  
Parametric Study ◽  
Failure Modes ◽  
Numerical Study ◽  
Simple Calculation ◽  
Constitutive Law ◽  
Structural Elements ◽  
Steel Columns ◽  
Safe Side ◽  
Steel Grades

Steel structural elements with cold-formed thin-walled sections are becoming increasingly common in buildings due to their lightness and ability to support large spans. In these members, local, distortional and global instabilities are important common failure modes. At high temperatures, these instability phenomena are intensified. This paper presents a numerical study on the behaviour of columns with cold-formed C-sections in case of fire when subjected to compression. A parametric study, considering different steel grades, temperatures and different cross-sections with different slendernesses, is presented. Comparisons are also made between the numerical results and analytical design rules, such as the EN1993-1-2, using its Annex E or its French National Annex, where a different constitutive law is recommended for cold-formed profiles. It is possible to conclude that the simple calculation rules are on the safe side but sometimes too conservative.

Parametric study and design procedure for planar silos and hoppers

2021 ◽  
Author(s):  
Evgeny Rabinovich ◽  
Haim Kalman ◽  
Per F. Peterson
Keyword(s):  
Parametric Study ◽  
Design Procedure

10.23: Parametric study on the fire resistance of steel columns with thermal gradients

ce/papers ◽  
2017 ◽  
Vol 1 (2-3) ◽  
pp. 2716-2725
Author(s):  
António Moura Correia ◽  
João Paulo Rodrigues ◽  
Venkatesh Kodur ◽  
José Pedro Correia
Keyword(s):  
Fire Resistance ◽  
Parametric Study ◽  
Thermal Gradients ◽  
Steel Columns

A Parametric Numerical Study of Radiative Transfer in Thermotropic Materials

2013 ◽  
Author(s):  
Adam C. Gladen ◽  
Susan C. Mantell ◽  
Jane H. Davidson
Keyword(s):  
Particle Size ◽  
Radiative Transfer ◽  
Optical Thickness ◽  
Parametric Study ◽  
Volume Fraction ◽  
Numerical Study ◽  
Anisotropic Scattering ◽  
Index Of Refraction ◽  
Spherical Particles ◽  
Size Parameter

A thermotropic material is modeled as an absorbing, thin slab containing anisotropic scattering, monodisperse, spherical particles. Monte Carlo ray tracing is used to solve the governing equation of radiative transfer. Predicted results are validated by comparison to the measured normal-hemispherical reflectance and transmittance of samples with various volume fraction and relative index of refraction. A parametric study elucidates the effects of particle size parameter, scattering albedo, and optical thickness on the normal-hemispherical transmittance, reflectance, and absorptance. The results are interpreted for a thermotropic material used for overheat protection of a polymer solar absorber. For the preferred particle size parameter of 2, the optical thickness should be less than 0.3 to ensure high transmittance in the clear state. To significantly reduce the transmittance and increase the reflectance in the translucent state, the optical thickness should be greater than 2.5 and the scattering albedo should be greater than 0.995. For optical thickness greater than 5, the reflectance is asymptotic and any further reduction in transmittance is through increased absorptance. A case study is used to illustrate how the parametric study can be used to guide the design of thermotropic materials. Low molecular weighted polyethylene in poly(methyl methacrylate) is identified as a potential thermotropic material. For this material and a particle radius of 200 nm, it is determined that the volume fraction and thickness should equal 10% and 1 mm, respectively.

Performance of parking steel column damaged by fire

2019 ◽  
Vol 10 (2) ◽  
pp. 138-154
Author(s):  
Farshid Masoumi ◽  
Ebrahim Farajpourbonab
Keyword(s):  
Cyclic Loading ◽  
Seismic Performance ◽  
Numerical Study ◽  
Mechanical Analysis ◽  
Content Type ◽  
Steel Columns ◽  
Fire Engineering ◽  
Steel Column ◽  
Concrete Coating ◽  
Fire Loading

Purpose The primary purpose of this research was to expand the knowledge base regarding the behavior of steel columns during exposure to fire. This paper presents the numerical study of the effect of heat on the performance of parking steel column in a seven-story steel building under cyclic loading. Design/methodology/approach In this research, the forces and deformations developed during a fire are estimated by using detailed 3D finite-element models. The analyses are in the form of a coupled thermo-mechanical analysis in two types of loading: concurrent loading (fire and cyclic loading) and non-concurrent loading (first fire and then cyclically), and the analyses have been conducted in both states of the fire loading with cooling and without cooling using the ABAQUS software. Further, it was investigated whether, during the fire loading, the specimen was protected by a 3-cm-thick concrete coating and how much it changes the seismic performance. After verification of the specimen with the experimental test results, the column model was investigated under different loading conditions. Findings The result of analyses indicates that the effect of thermal damage on the performance of steel columns, when cooling is happening late, is more than the state in which cooling occurs immediately after the fire. In this paper, thermal–seismic performance of parking steel columns has been specified and the effect of the fire damage has been investigated for the protected steel by concrete coating and to the non-protected steel, under both cooling and non-cooling states. Originality/value This study led to recommendations based on the findings and suggestions for additional work to support performance-based fire engineering. It is clear that predicting force and deformation on steel column during fire is complex and it is affected by many variables. Here in this paper, those variables are examined and proper results have been achieved.

scholarly journals ARMOUR UNIT STRUCTURAL RESPONSE - A PARAMETRIC STUDY

1988 ◽  
Vol 1 (21) ◽  
pp. 176
Author(s):  
C. David Anglin ◽  
William F. Baird ◽  
Etienne P.D. Mansard ◽  
R. Douglas Scott ◽  
David J. Turcke
Keyword(s):  
Wave Height ◽  
Parametric Study ◽  
Structural Integrity ◽  
Design Procedure ◽  
Structural Response ◽  
Design Parameters ◽  
Coastal Structures ◽  
Log Normal ◽  
Wave Induced ◽  
Hydraulic Stability

There is a general lack of knowledge regarding the nature and magnitude of loads acting on armour units used for the protection of rubblemound coastal structures. Thus, a comprehensive design procedure incorporating both the hydraulic stability and the structural integrity of the armour units does not exist. This paper presents the results of a detailed parametric study of the structural response of armour units to wave-induced loading in a physical breakwater model. The effect of the following design parameters is investigated: breakwater slope, armour unit location, wave period and wave height. This research has made a number of significant contributions towards the development of a comprehensive design procedure for concrete armour units. It has identified a linear relationship between the wave-induced stress in the armour units and the incident wave height. In addition, it has shown that the conditional probability of waveinduced stress given wave height can be estimated by a log-normal distribution. Finally, a preliminary design chart has been developed which incorporates both the structural integrity and the hydraulic stability of the armour units.

scholarly journals Gaussian Circular 2D FIR Filters Designed Using Analytical Approach

2020 ◽  
Vol 16 ◽  
Keyword(s):  
Analytical Approach ◽  
Design Procedure ◽  
Peak Frequency ◽  
Fir Filters ◽  
Chebyshev Series ◽  
Analytical Design ◽  
Frequency Transformation ◽  
Low Pass ◽  
Band Pass ◽  
2D Fir Filters

This paper proposes an analytical design procedure for a particular class of 2D filters, namelyGaussian-shaped, circularly-symmetric FIR filters. We approach both low-pass and band-pass circular filters,which are adjustable in selectivity and peak frequency. The design starts from a given 1D Gaussian prototypefilter, approximated using the Chebyshev series. A frequency transformation is applied to derive the circularfilter. Several design examples are provided for both types of filters. The filters designed through this methodare efficient, their frequency response results in a factored or nested form, convenient for implementation.

Investigation of Structural and Material Effects on Crashworthiness of Advanced High Strength Steel Columns

2003 ◽  
Author(s):  
Faycal Ben-Yahia ◽  
James A. Nemes ◽  
Farid Hassani
Keyword(s):  
Numerical Study ◽  
Hsla Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Column Height ◽  
Steel Columns ◽  
Advanced High Strength Steels ◽  
Element Simulation ◽  
Formed Channel ◽  
Good Agreement

An experimental and numerical study was performed to evaluate the crashworthiness of several advanced high strength steels. The behavior of two Dual Phase (DP) steels and an HSLA steel are compared by examining the crush response of longeron column specimens, experimentally and computationally. The closed section columns, fabricated by spot welding formed channel sections, in both single hat and double hat configurations were exposed to 182 kg and 454 kg axial impacts at different velocities. Final column height and impact force history were recorded and compared with results of finite element simulation of the columns. Good agreement was found between experiments and computations.

Inelastic seismic shear amplification due to higher mode effects in reinforced concrete coupled walls

2021 ◽  
pp. 875529302110533
Author(s):  
Gabriel Rivard ◽  
Steeve Ambroise ◽  
Patrick Paultre
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Numerical Study ◽  
Plastic Hinge ◽  
Experimental Studies ◽  
Physical Parameters ◽  
Intensity Level ◽  
Shear Forces ◽  
Coupled Walls ◽  
Seismic Shear

Recent numerical and experimental studies on reinforced concrete shear walls and coupled walls have shown shear forces greater than expected when the walls are subjected to earthquakes at an intensity level that does not exceed the design values. This amplification of shear forces is attributable to the effects of higher modes after the walls develop a plastic hinge at the base. These effects have been recently recognized in North American design codes for cantilever walls and is currently neglected in the design of ductile coupled walls. As part of the research program described in this article, a parametric study was carried out on coupled wall systems to identify the geometric and physical parameters having the greatest influence on the seismic shear amplification. Using the results of this parametric study, an extensive numerical study was conducted on classes of ductile coupled walls subjected to seismic excitation representative of Western and Eastern Canada. This extensive study led to the establishment of shear amplification prediction equations for use in building codes.

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