scholarly journals PERFORMANCE BASED DESIGN OF UNBRACED STEEL FRAMES EXPOSED TO NATURAL FIRE SCENARIOS

2016 ◽  
Author(s):  
Carlos Couto ◽  
Thiago Silva ◽  
Martina Carić ◽  
Paulo Vila Real ◽  
Davor Skejić
Keyword(s):  
Fire Resistance ◽  
Steel Frames ◽  
Design Methods ◽  
The Other ◽  
Performance Based Design ◽  
The Finite Element Method ◽  
Natural Fire ◽  
Fire Scenarios ◽  
Buckling Coefficient ◽  
Structural Engineers

<p>According to the Eurocode 3 Part 1-2 (EN1993-1-2) (CEN 2005b), it is possible for structural engineers to consider physical based thermal actions and to do performance based design instead of using prescriptive rules based on nominal fire curves. However, some uncertainties remain in the use of such approaches. This study focus on the clarification of the use of the simplified design methods to assess the fire resistance of unbraced steel frames exposed to fire. On the other hand, a recent study (Couto et al. 2013) suggests the use of a buckling coefficient of 1.0 for all the columns except those belonging to the first storey of a pinned framed where 2.0 should be taken instead and it is unclear if the consideration of such values for the buckling lengths is adequate when using performance based designs.</p>In this study, a comparison is made between simple and advanced calculation models and it is demonstrated that the simple design methods, using the suggested buckling coefficients to calculate the fire resistance of the frames are safe sided when compared to the use of advanced calculations using the finite element method (FEM).

Modeling the Fire Resistance of Wood-Frame Office Buildings

1997 ◽  
Vol 15 (4) ◽  
pp. 308-338 ◽  
Author(s):  
Edmond C.Y. Lin ◽  
J.R. Mehaffey
Keyword(s):  
Fire Resistance ◽  
Computer Models ◽  
Performance Based Design ◽  
Safety Engineering ◽  
Frame Buildings ◽  
Fire Scenarios ◽  
Flow Through ◽  
Wood Frame ◽  
The Times ◽  
Fire Origin

A fire safety engineering analysis has been undertaken to deter mine the fire resistance of gypsum protected wood stud walls in six simulated of fice fire scenarios. Each scenario consists of an office-furnishing fire in an unsprinklered compartment with windows shut and doors closed at the initiation of fire. Employing three computer models, CFAST 2.0, BREAK 1, and WALL 2D, temperature throughout the compartment of fire origin, heat transfer from the fire to the walls, and the structural degradation of the walls are calculated. The times to failure of the windows and the doors are also calculated. The fire growth caused by the increased air flow through the windows and doors is determined. It is demonstrated that the three computer models could be employed to deliver performance-based design for fire resistance of wood-frame buildings.

scholarly journals Performance-based design of RC beams using an equivalent standard fire

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Robert Kuehnen ◽  
Maged Youssef ◽  
Salah El-Fitiany
Keyword(s):  
Performance Based Design ◽  
Rc Beams ◽  
Fire Event ◽  
Content Type ◽  
Natural Fire ◽  
Standard Fire ◽  
Fire Scenarios ◽  
The Moment ◽  
Equivalent Method ◽  
Fire Design

Purpose The design of buildings for fire events is essential to ensure occupant safety. Supplementary to simple prescriptive methods, performance-based fire design can be applied to achieve a greater level of safety and flexibility in design. To make performance-based fire design more accessible, a time-equivalent method can be used to approximate a given natural fire event using a single standard fire with a specific duration. Doing so allows for natural fire events to be linked to the wealth of existing data from the standard fire scenario. The purpose of this paper is to review and assess the application of an existing time-equivalent method in the performance-based design of reinforced concrete (RC) beams. Design/methodology/approach The assessment is established by computationally developing the moment-curvature response of RC beam sections during fire exposure. The sectional response due to natural fire and time equivalent fire are compared. Findings It is shown that the examined time equivalent method is able to predict the sectional response with suitable accuracy for performance-based design purposes. Originality/value The research is the first to provide a comprehensive evaluation of the moment-curvature diagram of RC beams using time-equivalent standard fire scenarios that model realistic fire scenarios.

Buckling Analysis of Steel Frames Exposed to Natural Fire Scenarios

Structures ◽  
2017 ◽  
Vol 10 ◽  
pp. 76-88 ◽  
Author(s):  
Thiago Silva ◽  
Martina Carić ◽  
Carlos Couto ◽  
Paulo Vila Real ◽  
Nuno Lopes ◽  
...  
Keyword(s):  
Steel Frames ◽  
Buckling Analysis ◽  
Natural Fire ◽  
Fire Scenarios

Anthropogenic Landscapes

2017 ◽  
Author(s):  
Christopher I. Roos
Keyword(s):  
Large Scale ◽  
Fire Regimes ◽  
Religious Practice ◽  
The Other ◽  
Wild Plant ◽  
Lower Intensity ◽  
Anthropogenic Landscapes ◽  
Natural Fire ◽  
Fire Use ◽  
Plant Foraging

It has been suggested that anthropogenic burning may have altered Southwest landscapes at a large scale. Southwestern biomes vary in their propensity for and their susceptibility to anthropogenic burning practices. Anthropogenic burning to enhance the productivity of wild plant foraging or agriculture was probably limited in scale; on the other hand, fire use in hunting, religious practice, and warfare may have impacted larger scales, though at lower intensity. Middle-elevation forests, woodlands, and grasslands were the biotic zones most likely to be impacted by anthropogenic burning, but sophisticated mimicry of natural fire regimes means that the evidence of such impact is ambiguous.

scholarly journals Practical method to predict the axial capacity of RC columns exposed to standard fire

2018 ◽  
Vol 9 (4) ◽  
pp. 266-286 ◽  
Author(s):  
Salah F. El-Fitiany ◽  
Maged A. Youssef
Keyword(s):  
Concrete Strength ◽  
Practical Method ◽  
Simple Method ◽  
Rc Columns ◽  
Content Type ◽  
Natural Fire ◽  
Rc Structures ◽  
Axial Capacity ◽  
Standard Fire ◽  
Structural Engineers

Purpose Existing analytical methods for the evaluation of fire safety of reinforced concrete (RC) structures require extensive knowledge of heat transfer calculations and the finite element method. This paper aims to propose a rational method to predict the axial capacity of RC columns exposed to standard fire. Design/methodology/approach The average temperature distribution along the section height is first predicted for a specific fire scenario. The corresponding distribution of the reduced concrete strength is then integrated to develop expressions to calculate the axial capacity of RC columns exposed to fire from four faces. Findings These expressions provide structural engineers with a rational tool to satisfy the objective-based design clauses specified in the National Code of Canada in lieu of the traditional prescriptive methods. Research limitations/implications The research is limited to standard fire curves and needs to be extended to cover natural fire curves. Originality/value This paper is the first to propose an accurate yet simple method to calculate the axial capacity of columns exposed to standard fire curves. The method can be applied using a simple Excel sheet. It can be further developed to apply to natural fire curves.

Fire of steel and composite beam bridges

2019 ◽  
Author(s):  
Henryk Zobel ◽  
Wojciech Karwowski ◽  
Agnieszka Golubińska ◽  
Thakaa Al-Khafaji
Keyword(s):  
Fire Resistance ◽  
Composite Beam ◽  
Structural Integrity ◽  
Bridge Structure ◽  
Long Span ◽  
Long Span Bridge ◽  
Bridge Structures ◽  
Fire Scenarios ◽  
Design Construction ◽  
Cable Stayed Bridges

<p>The problem of bridge fires is growing. Because of a bad experience in Poland, it was decided to improve fire resistance of long span bridge structures, and of cable-stayed bridges in particular. Statistics shows that fire is a real threat to this kind of structure. They also confirm that the worst results of fire are for those with an orthotropic deck rather than with a concrete one. The basic problems to solve are how to predict fire resistance of a particular bridge and how to ensure safety and structural integrity of the bridge structure. Taking into account the fact that bridge standards do not include information relating to fire protection, and fire standards do not determine rules for design, construction and maintenance of such structures, there are no regulations for this problem. Fire scenarios are devoted to buildings, but the thermo-structural behavior of bridges is different.</p>

scholarly journals Influence of the Mechanical Properties of Elastoplastic Materials on the Nanoindentation Loading Response

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4842
Author(s):  
Huanping Yang ◽  
Wei Zhuang ◽  
Wenbin Yan ◽  
Yaomian Wang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
The Other ◽  
Equivalent Model ◽  
Strain Hardening Exponent ◽  
Mechanical Parameters ◽  
The Finite Element Method ◽  
Fem Simulations ◽  
Elastoplastic Materials

The nanoindentation loading response of elastoplastic materials was simulated by the finite element method (FEM). The influence of the Young’s modulus E, yield stress σy, strain hardening exponent n and Poisson’s ratio ν on the loading response was investigated. Based on an equivalent model, an equation with physical meaning was proposed to quantitatively describe the influence. The calculations agree well with the FEM simulations and experimental results in literature. Comparisons with the predictions using equations in the literature also show the reliability of the proposed equation. The investigations show that the loading curvature C increases with increasing E, σy, n and ν. The increase rates of C with E, σy, n and ν are different for their different influences on the flow stress after yielding. It is also found that the influence of one of the four mechanical parameters on C can be affected by the other mechanical parameters.

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