• Computers and Concrete
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• v.25 no.6
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• pp.497-507
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• 2020

This paper presents a numerical method for evaluating fire performance of prestressed concrete (PC) T shaped bridge girders under combined effect of structural loading and hydrocarbon fire exposure conditions. A numerical model, developed using the computer program ANSYS, is employed to investigate fire response of PC T shaped bridge girders by taking into consideration structural inherent parameters, namely; arrangement of prestressing strands with in the girder section, thickness of concrete cover over prestressing strands, effective degree of prestress and content of prestressing strands. Then, a sequential thermo-mechanical analysis is performed to predict cross sectional temperature followed by mechanical response of T shaped bridge girders. The validity of the numerical model is established by comparing temperatures, deflections and failure time generated from fire tests. Through numerical studies, it is shown that thickness of concrete cover and arrangement of prestressing strands in girder section have significant influence on the fire resistance of PC T shaped bridge girders. Increase in effective degree of prestress in strands with triangular shaped layout and content in prestressing strands can slow down the progression of deflections in PC T shaped bridge girder towards the final stages of fire exposure, to thereby preventing sudden collapse of the girder. Rate of deflection based failure criterion governs failure in PC T shaped bridge girders under most hydrocarbon fire exposure conditions. Structural inherent parameters incorporated into sectional configuration can significantly enhance fire resistance of PC bridge girders; thus mitigating fire induced collapse of these bridge girders.

• Fire Science and Engineering
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• v.24 no.2
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• pp.89-96
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• 2010

In this research, exterior material combustion experiment was really tested to evaluate fire risks of aluminium complex panel which is used a lot for building exterior material. As a result, We saw fast fire spreading of aluminium complex panel. The reason is polyethylene in aluminum complex panel combust spreading fast fire flame vertically. In this test, the highest heat release rate of aluminum complex panel was 1,144 kW and surface temperature which is measured by thermocouple went up to more than $903.3^{\circ}C$, that temperature is quite a higher than $660^{\circ}C$ which is aluminum melting temperature. So, fire of aluminum complex panel can be evaluated to give us severe damage both by fast fire spreading vertically and by fire spreading through openings internally. These results from real experiment will be able to use to predict fire spreading of aluminum complex panel by comparing to modeling materialization of aluminum complex panel in the future.

• Fire Science and Engineering
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• v.25 no.6
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• pp.127-135
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• 2011

In this study, we assumed the kitchen fire raising the highest fire rate in apt. and analyzed the fire risk to use CFD in order to estimate the problem of evacuation equipment and the fire vulnerability of 16 or fewer storey apartment. Fire occurring in the kitchen is expended to the livingroom and other rooms. We analyzed that the temperature effected by heat was more than $60^{\circ}C$ after 90 sec in the entrance of apartment unit. If fire is early recognized by men and men don't escape in time, it have too huge demage to block the exit. When the evacuation equipment suggested in this study was installed in order to solve the problem of evacuation equipment, we analyzed that it was estimated more than safe in safety evaluation by heat and heat flux.

• Fire Science and Engineering
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• v.23 no.2
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• pp.41-48
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• 2009

In this paper, to overcome the limitation of the existing wired fire sensors and alert facilities, the real-time temperature data collected from the fire detectors applied USN is analyzed the time series and spacial features of temperature inside building using the GIS spatial modeling method. Resulting from the analysis of the distribution features by the spacial location and time series, the temperature sensors applied USN is installed by the consideration of the spacial structures features. This paper will suggest the objective and practical guideline of installation of fire sensors applied USN.

• Structural Engineering and Mechanics
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• v.48 no.5
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• pp.643-660
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• 2013

Reinforced concrete structures are vulnerable to high temperature conditions such as those during a fire. At elevated temperatures, the mechanical properties of concrete and reinforcing steel as well as the bond between steel rebar and concrete may significantly deteriorate. The changes in the bonding behavior may influence the flexibility or the moment capacity of the reinforced concrete structures. The bond strength degradation is required for structural design of fire safety and structural repair after fire. However, the investigation of bonding between rebar and concrete at elevated temperatures is quite difficult in practice. In this study, bond constitutive relationships are developed for normal and high-strength concrete (NSC and HSC) subjected to fire, with the intention of providing efficient modeling and to specify the fire-performance criteria for concrete structures exposed to fire. They are developed for the following purposes at high temperatures: normal and high compressive strength with different type of aggregates, bond strength with different types of embedment length and cooling regimes, bond strength versus to compressive strength with different types of embedment length, and bond stress-slip curve. The proposed relationships at elevated temperature are compared with experimental results.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.122-128
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• 2007

GIS is used much research for efficient forest fire management and forecasting and slope has been known as high-leverage thing in spread of forest fire specially. Various algorithms are used usually to calculate slope angle of topography from DEM(Digital elevation model). However, because spread speed of forest fire is different according to uphill slope and downhill slope, it need new slope calculation algorithm. Therefore, developed slope calculation algorithm can reflect uphill slope and forest fire spread speed of looking downhill slope.

• Steel and Composite Structures
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• v.44 no.6
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• pp.769-788
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• 2022

In this paper a mathematical model for the prediction of the fire resistance of slim-floor steel beams based on an Artificial Neural Network modeling procedure is presented. The artificial neural network models are trained and tested using an analytical database compiled for this purpose from analytical results based on FEM. The proposed model was selected as the optimum from a plethora of alternatives, employing different activation functions in the context of Artificial Neural Network technique. The performance of the developed model was compared against analytical results, employing several performance indices. It was found that the proposed model achieves remarkably improved predictions of the fire resistance of slim-floor steel beams. Moreover, based on the optimum developed AN model a closed-form equation for the estimation of fire resistance is derived, which can prove a useful tool for researchers and engineers, while at the same time can effectively support the teaching of this subject at an academic level.

• Fire Science and Engineering
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• v.18 no.4
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• pp.64-71
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• 2004

This paper describes the result of the pump room fire analysis of the nuclear power plant using CFAST fire modeling code developed by NIST. The sensitivity studies are performed over the input parameters of CFAST: the constrained or unconstrained fire, Lower Oxygen Limit (LOL), Radiative Fraction (RF), and the opening ratio of the fire doors. According to the results, a pump room fire is the ventilation-controlled fire, so it is adequate that the value of LOL is 10% which is also the default value. It is anlayzed that the Radiative Fraction does not affect the temperature of the upper gas layer. It is appeared that the integrity of the cable located at the upper layer is maintained except for the safety pump at the fire area and the Conditional Core Damage Probability (CCDP) is 9.25E-07. It seems that CCDP result is more realistic and less uncertain than that of Fire Hazard Analysis (FHA).

• The KIPS Transactions:PartB
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• v.15B no.2
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• pp.87-94
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• 2008

In this paper, we propose a new vision-based fire detection method for a real-life application. Most previous vision-based methods using color information and temporal variation of pixel produce frequent false alarms because they used a lot of heuristic features. Furthermore there is also computation delay for accurate fire detection. To overcome these problems, we first detected candidated fire regions by using background modeling and color model of fire. Then we made probabilistic models of fire by using a fact that fire pixel values of consecutive frames are changed constantly and applied them to a Bayesian Network. In this paper we used two level Bayesian network, which contains the intermediate nodes and uses four skewnesses for evidence at each node. Skewness of R normalized with intensity and skewnesses of three high frequency components obtained through wavelet transform. The proposed system has been successfully applied to many fire detection tasks in real world environment and distinguishes fire from moving objects having fire color.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.1
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• pp.116-122
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• 2001

In this paper, to make a base of the fire safety assessment about ship's fire protection design and Classification Society rule, statistical informations and modeling techniques for the fire safety engineering are investigated and probabilistic safety assessment methods in the structural reliability engineering are introduced. FSEM(Fire Safety Evaluation Module) developed in this paper calculates the probability of fatality, which can be used as an index of fire safety. FSEM is used to calculate the probability of fatality of the evacuees in a small room installed according to the rules for fire-proof. Sensitivity analysis is executed to investigate FSEM's applicability to ship. From results, the necessity of new criterion for ship's fire safety design, the need to study the human behavior in the evacuation from fire, and the development of new fire progress model considering special situations in ships are acknowledged.