• Title/Summary/Keyword: Fire Behavior

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Boundary Conditions and Fire Behavior of Concrete Filled Tubular Composite Columns

  • Rodrigues, Joao Paulo C.;Correia, Antonio J.M.;Kodur, Venkatesh
    • International Journal of High-Rise Buildings
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    • v.7 no.4
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    • pp.313-325
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    • 2018
  • Concrete-filled steel tubular (CFST) members are commonly used as composite columns in modern construction. However, the current guidelines for members' fire design (EN1994-1-2) have been proved to be unsafe in case the relative slenderness is higher than 0.5. In addition, the simplified design methods of Eurocode 4 are limited to circular and square CFST columns, while in practice columns with rectangular and elliptical hollow sections are being increasingly used because of their architectural aesthetics. In the last years a large experimental research has been carried out at Coimbra University on the topic. They have been tested concrete filled circular, square, rectangular and elliptical hollow columns with restrained thermal elongation. Some parameters such as the slenderness, the type of cross-section geometry as well as the axial and rotational restraint of the surrounding structure to the column have been tested in order to evaluate their influence on the fire resistance of such columns. In this paper it is evaluated the influence of the boundary conditions (pin-ended and semi-rigid end-support conditions) on the behavior of the columns in case of fire. In these tests it could not be seen a marked effect of the tested boundary conditions but it is believed that the increasing of rotational stiffness increases the fire resistance of the columns.

Application of Deep Learning: A Review for Firefighting

  • Shaikh, Muhammad Khalid
    • International Journal of Computer Science & Network Security
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    • v.22 no.5
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    • pp.73-78
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    • 2022
  • The aim of this paper is to investigate the prevalence of Deep Learning in the literature on Fire & Rescue Service. It is found that deep learning techniques are only beginning to benefit the firefighters. The popular areas where deep learning techniques are making an impact are situational awareness, decision making, mental stress, injuries, well-being of the firefighter such as his sudden fall, inability to move and breathlessness, path planning by the firefighters while getting to an fire scene, wayfinding, tracking firefighters, firefighter physical fitness, employment, prediction of firefighter intervention, firefighter operations such as object recognition in smoky areas, firefighter efficacy, smart firefighting using edge computing, firefighting in teams, and firefighter clothing and safety. The techniques that were found applied in firefighting were Deep learning, Traditional K-Means clustering with engineered time and frequency domain features, Convolutional autoencoders, Long Short-Term Memory (LSTM), Deep Neural Networks, Simulation, VR, ANN, Deep Q Learning, Deep learning based on conditional generative adversarial networks, Decision Trees, Kalman Filters, Computational models, Partial Least Squares, Logistic Regression, Random Forest, Edge computing, C5 Decision Tree, Restricted Boltzmann Machine, Reinforcement Learning, and Recurrent LSTM. The literature review is centered on Firefighters/firemen not involved in wildland fires. The focus was also not on the fire itself. It must also be noted that several deep learning techniques such as CNN were mostly used in fire behavior, fire imaging and identification as well. Those papers that deal with fire behavior were also not part of this literature review.

Burning Characteristics of Wood-based Materials using Cone Calorimeter and Inclined Panel Tests

  • Park, Joo-Saeng;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.18-25
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    • 2002
  • Research to discuss the fire performance of materials requires tools for measuring their burning characteristics and validated fire growth models to predict fire behavior of the materials under specific tire scenarios using the measured properties as input for the models. In this study, burning characteristics such as time to ignition, weight loss rate, flame spread, heat release rate, total heat evolved, and effective heat of combustion for four types of wood-based materials were evaluated using the cone calorimeter and inclined panel tests. Time to ignition was affected by not only surface condition and specific gravity of the tested materials but also the type and magnitude of heat source. Results of weight loss rate, measured by inclined panel tests, indicated that heat transfer from the contacted flame used as the heat source into the inner part of the specimen was inversely proportional to specific gravity of material. Flame spread was closely related with ignition time at the near part of burning zone. Under constant and severe external heat flux, there was little difference in weight loss rate and total heat evolved between four types of wood-based panels. More applied heat flux caused by longer ignition time induced a higher first peak value of heat release rate. Burning characteristics data measured in this study can be used effectively as input for fire growth models to predict the fire behavior of materials under specific fire scenarios.

Numerical Study of Fire Behavior Induced by Gas Leakage in Combined Cycle Power Plant (복합발전플랜트 내의 가스 화재 거동에 관한 수치해석)

  • Park, Jaeyong;Sung, Kunhyuk;Li, Longnan;Choi, Jinwook;Kim, Daejoong;Lee, Seong Hyuk;Ryou, Hong Sun
    • Journal of ILASS-Korea
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    • v.20 no.2
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    • pp.107-113
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    • 2015
  • To date, the demand for Combined Cycle Power Plant (CCPP) has been continuously increased to overcome the problem of air pollution and lack of energy. In particular, the underground CCPP is exposed to substantial fire and explosion risks induced by gas leakage. The present study conducted numerical simulations to examine the fire behavior and gas leakage characteristics for a restricted region including gas turbine and other components used in a typical CCPP system. The commercial code of FLUENT V.14 was used for simulation. From the results, it was found that flammable limit distribution of leakage gas affects fire behavior. Especially, the flame is propagated in an instant in restricted region with LNG gas. In addition, consequence analysis factors such as critical temperature and radiation heat flux are introduced. These results would be useful in making the safety guidelines for the underground CCPP.

Effective Use Of The Evacuation Behavior Of The Crowd In A Fire At The Small Theater (소극장에서 화재시 군중의 피난행동을 이용한 효율적인 대피방법)

  • Shin, Hongkyung;Jeong, Myeongjin;Park, Sojin;Heo, Subin
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.1
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    • pp.249-255
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    • 2019
  • Currently, most small theaters in Korea are not equipped with fire escape prevention laws unlike large theaters. The small theater is a place where many people stay in a small space, which can lead to a great deal of damage in the event of a fire. Therefore, we propose an efficient evacuation method using the evacuation behavior of the crowd as a way to minimize the casualties in case of a fire in a small theater.

Study on building room fire development stages (건축물 실내화재의 단계에 대한 연구)

  • Cha, Jong-Ho
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.169-172
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    • 2008
  • The purpose of this paper is to summarize characteristics of fire growth stages, combustion proceeding, human behavior factors against fire, fire active protections, fire alarms in order to perform public safety and protection, personnel property protection, with identification of economic analysis aspects based on respective stages classified as fire generation- fire growth- flashover- fire extinction, which is differ from previous studies that based on distinct concepts such as fire stages, escapes, building construction, fire sensing.

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Behavior of Fire Resistance Engineered Cementitious Composites(FR-ECC) under Fire Temperature (화재 온도를 받는 고인성.고내화성 시멘트 복합체의 거동)

  • Han, Byung-Chan;Kwon, Young-Jin;Kim, Jae-Hwan
    • Journal of the Korea Concrete Institute
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    • v.19 no.2
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    • pp.189-197
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    • 2007
  • Concrete tunnel lining must be designed to having the fireproof performance because the lining are sometimes exposed to very high temperature due to traffic accident. Such fire temperature may cause explosion of concrete, or collapse of tunnel structure. The purpose of this study is to obtain the fundamental fireproof behavior of fire resistance-engineered cementitious composites(FR-ECC) under fire temperature in order to use the fire protection material in tunnel lining system. The present study conducted the experiment to simulate fire temperature by employing 2 types of FR-ECC and investigated experimentally the explosion and cracks in heated surface of these FR-ECC. Employed temperature curve were hydro carbon(HC, ECl) criterion, which are severe in various criterion of fire temperature. The numerical analysis is carried out the nonlinear transient heat flow analysis and verified against the experimental data. The complex features of behavior in fire conditions, such as thermal expansion, plasticity, cracking or crushing, and material properties changing with temperature are considered. By the use of analytical model, the concrete tunnel subjected to fire loads were analyzed and discussed. With comparison of current concrete materials and FR-ECC, the experimental and analytical results of FR-ECC shows the better fire resistance performance than the other.

Establishment of Fire Reliability Assessment Method for Structural Strength (화재시 구조강도에 대한 신뢰성 평가방법의 정립)

  • Park, Chang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.54-62
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    • 2017
  • This paper describes the behavior and failure probability of the basic structural members in a fire for the fire safety assessment of offshore structures. A fire safety assessment can be accomplished by comparing the fire resistance of the members with the fire severity of the heat load due to fire. The fire severity is represented as the maximum temperature of the members using the Eurocode 1 standard fire curve and heat transfer equation. On the other hand, the fire resistance is the limiting temperature calculated by a simplified formula in the case of simple structural members. Considering the complexity of FPSOs and offshore structures, a general-purpose structural analysis program should be used and the limiting temperature obtained by analyzing the structural strength of the members through an elasto-plastic analysis with a large deflection, and compared with the maximum temperature. Also, the equality of these two methods of evaluating the fire resistance was confirmed by comparing them. Following three criteria, the strength, serviceability and stability, three failure modes, namely the first failure of a hinge, large deflection and buckling, were chosen. The failure temperature was verified for each failure mode. using the AFOSM method in the equation of the fire severity and fire resistance, thereby giving the failure probability of the member. By applying these processes to the example of a beam and plate, the behavior of the structure and failure (temperature?) of each failure mode can be determined.