scholarly journals Numerical and Experimental Analysis of Fire Resistance for Steel Structures of Ships and Offshore Platforms

Fire ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Marina Gravit ◽  
Daria Shabunina
Keyword(s):  
Fire Resistance ◽  
Oil And Gas ◽  
Fire Regime ◽  
Experimental Studies ◽  
Steel Structures ◽  
Fire Regimes ◽  
Mineral Wool ◽  
Offshore Platforms ◽  
Transfer Coefficients ◽  
Standard Fire

The requirements for the fire resistance of steel structures of oil and gas facilities for transportation and production of hydrocarbons are considered (structures of tankers and offshore platforms). It is found that the requirements for the values of fire resistance of structures under hydrocarbon rather than standard fire conditions are given only for offshore stationary platforms. Experimental studies on the loss of integrity (E) and thermal insulating capacity (I) of steel bulkheads and deck with mineral wool under standard and hydrocarbon fire regimes are presented. Simulation of structure heating was performed, which showed a good correlation with the experimental results (convective heat transfer coefficients for bulkheads of class H: 50 W/m2·K; for bulkheads of class A: 25 W/m2·K). The consumption of mineral slabs and endothermic mat for the H-0 bulkhead is predicted. It is calculated that under a standard fire regime, mineral wool with a density of 80–100 kg/m2 and a thickness of 40 to 85 mm should be used; under a hydrocarbon fire regime, mineral wool with a density above 100 kg/m2 and a thickness of 60–150 mm is required. It is shown that to protect the structures of decks and bulkheads in a hydrocarbon fire regime, it is necessary to use 30–40% more thermal insulation and apply the highest density of fire-retardant material compared to the standard fire regime. Parameters of thermal conductivity and heat capacity of the applied flame retardant in the temperature range from 0 to 1000 °C were clarified.

scholarly journals Fire Protective Glass Fiber Reinforced Concrete Plates for Steel Structures under Different Types of Fire Exposure

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 187
Author(s):  
Marina Gravit ◽  
Elena Golub ◽  
Boris Klementev ◽  
Ivan Dmitriev
Keyword(s):  
Fire Resistance ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Lightweight Concrete ◽  
Limit State ◽  
Single Layer ◽  
Steel Structures ◽  
Fiber Reinforced Concrete ◽  
Fire Tests ◽  
Standard Fire

In a situation where a fire occurs either in a tunnel with a burning vehicle carrying petroleum products, at an offshore platform, or at an oil and gas asset to be protected, such a case is commonly described using a hydrocarbon fire curve. Therefore, it is extremely important to design construction, which can maintain stability and bearing capacity both under the standard and hydrocarbon fire modes. The purpose in this work is to hold a behavior simulation of a steel structure with fireproofing ensured through lightweight concrete slabs reinforced with fiber glass as well as a validation of the outcomes by assessing the experimental findings obtained from the relevant fire tests. A fire resistance study was carried out here for steel structures with a profile ratio of 156 mm−1 for the cases of a standard fire and of a hydrocarbon fire. A constant static load of 687 kN (70 tf) was taken for standard fire and 294 kN (30 tf) for hydrocarbon fire; the column was under vertical compression with one end resting on a hinged support and the other end rigidly fixed. The specimen design incorporated single-layer box-section cladding made of Pyro-Safe Aestuver T slabs, 40 mm thick and of a 650 kg/m3 density, pre-cut to fit the column size. The column strength loss (R) ultimately occurred after 240 min in the standard fire case and after 180 min in the hydrocarbon fire case. As the breach in the fireproofing structural integrity (E) or the installation accuracy cannot be considered, the limit state indicators may show certain discrepancies. According to the simulation performed using SOFiSTiK software, the design fire resistance rating of the structure in a hydrocarbon fire case was 58% higher than the figure obtained by holding fire tests due to the slabs cracking during the experiment session; the discrepancy between the outcomes of the session and the simulation in a standard fire case was as much as 15%.

Simulation of charring depth of timber structures when exposed to non-standard fire curves

2018 ◽  
Vol 9 (1) ◽  
pp. 63-76 ◽  
Author(s):  
Jean-Christophe Mindeguia ◽  
Guillaume Cueff ◽  
Virginie Dréan ◽  
Gildas Auguin
Keyword(s):  
Fire Resistance ◽  
Experimental Studies ◽  
Thermal Exposure ◽  
Performance Based Design ◽  
Analytical Models ◽  
Content Type ◽  
Char Layer ◽  
Wooden Structure ◽  
Standard Fire ◽  
A Performance

Purpose The fire resistance of wooden structures is commonly based on the calculation or measurement of the char layer. Designers usually estimate the char layer at the surface of a structural element by using analytical models. Some of these charring models can be found in regulations, as Eurocode 5. These analytical models, quite simple to use, are only reliable for the standard fire curve. In that case, the design of the structure is qualified as “prescriptive-based design” and can lead to oversizing the structure. Optimization of a structure can be achieved by using a “Performance-based design”, where realistic fire scenarios are taken into account by means of more or less complex models [parametric fires, two-zones models, computational fluid dynamics (CFD)]. For these so-called “natural fires”, no model for charring is available. The purpose of this paper is to present a novel methodology for applying a performance-based design to a simple timber structure. Design/methodology/approach This paper presents the development of a numerical model aiming to simulate the thermal transfer and charring in wood, under any type of thermal exposure, including non-standard fire curves. After presenting the physical background, the model is calibrated and compared to existing experimental studies on wood samples exposed to different fire curves. The model is then used as a tool for assessing the fire resistance of a common wooden structure exposed to standard and non-standard fire curves. Findings The results show that the fire resistance is obviously dependent on the choice of the thermal exposure. The reliability of the model is also discussed and the importance of taking into account particular reactions in wood during heating is underlined. Originality/value One aim of this paper is to show the opportunity to apply a performance-based approach when designing a wooden structure. It shows that more knowledge of the material behaviour under non-standard fires is still needed, especially during the decay phase.

Evaluation of fire-retardant effectiveness of coatings for steel structures

2020 ◽  
pp. 43-54
Author(s):  
Владимир Ильич Голованов ◽  
Андрей Владимирович Пехотиков ◽  
Владимир Валерьевич Павлов
Keyword(s):  
Thermal Conductivity ◽  
Fire Resistance ◽  
Fire Protection ◽  
Oil And Gas ◽  
Fire Retardant ◽  
Steel Structures ◽  
Building Structures ◽  
Load Bearing ◽  
Passive Fire Protection ◽  
Actual Fire

Представлены результаты анализа экспериментальной и аналитической оценки огнезащитной эффективности покрытий для стальных конструкций. Обобщены данные многолетних исследований по определению зависимостей от температуры таких теплофизических характеристик, как теплопроводность и теплоемкость. Разработана структурно-методологическая схема выбора огнезащитных покрытий для стальных конструкций в целях обеспечения нормативных требований по огнестойкости. Проведены экспериментальные исследования по определению огнезащитной эффективности терморасширяющихся покрытий на эпоксидной основе при воздействии температурного режима горения углеводородов. Рассмотрен вопрос о гармонизации методики экспериментальной оценки огнезащитной эффективности средств огнезащиты для стальных конструкций с действующими европейскими нормами. Установлены критерии выбора пассивной огнезащиты, зависящие от области применения способов огнезащиты. Steel structures have high strength, relative lightness and durability, but when exposed to high temperatures in a fire, they deform, lose stability and load-bearing capacity. The collapse of load-bearing steel structures can occur in 10-15 minutes after the fire start. The actual fire resistance limit of structures can be increased by using the active and passive fire protection systems. The use of the active system for increasing the actual fire resistance limit is not provided in the regulatory documents. Passive fire protection is a complex of technical solutions including the use of non-flammable materials and bulging compounds. It is also an integral part of the building structure that ensures the required fire resistance limit. Assessment of fire resistance of building structures of residential, public, warehouse and industrial buildings is carried out taking into account the temperature regime (cellulose) of a standard fire. At oil and gas, petrochemical enterprises as well as at oil production platforms fires can occur at combustion of various hydrocarbon fuels which are characterized by a rapid temperature increase to 1100 °C. In this case, in accordance with GOST R EN 1363-2-2014, the temperature regime of hydrocarbon combustion is used to assess the fire resistance of building structures. The fire-retardant effectiveness of fire protection means for steel structures is determined by the heating time of the standard I-shaped column without applying a static load on the sample to the average “critical” temperature of the steel of 500 °C. Materials used for fire protection of steel structures must have a good thermal insulation ability, which is estimated by the coefficient of thermal conductivity. When heated to high temperatures, the thermal conductivity coefficient of fire-resistant materials varies depending on their composition and temperature. Based on the analysis of research to determine the fire-retardant effectiveness of fire protection means for steel structures there was developed a structural and methodological scheme that allows to make a choice of fire protection. Currently, as a fire protection there are widely used intumescent paints and thermo-expandable coatings. Taking into account the lack of knowledge of the influence of long-term operation and a large number of other technological factors on the fire-retardant effectiveness of coatings of steel structures covered with intumescent paints, it would be right to limit the use of such type of fire protection for load-bearing structures contributing to the overall sustainability of buildings with a required fire resistance of R 30. For fire protection of steel structures of oil and gas facilities located in the open air, in severe climatic conditions and exposed to aggressive environments there is successfully used a thermo-expandable two-component epoxy-based coating. The analysis of experimental data showed that the use of epoxy-based coatings is suitable for metal structures in the open air. In closed rooms the epoxy intumescent coating should not be used because at high temperature in a fire it ignites with toxic combustion products release.

scholarly journals Fire behavior of shallow prestressed hollow core slabs from computational modeling

2020 ◽  
Vol 13 (2) ◽  
pp. 398-432
Author(s):  
D. L. ARAÚJO ◽  
G. D. C. PINTO
Keyword(s):  
Fire Resistance ◽  
Numerical Models ◽  
Precast Concrete ◽  
Fire Behavior ◽  
Steel Structures ◽  
Analytical Models ◽  
Structural Systems ◽  
Hollow Core ◽  
Finite Element Software ◽  
Standard Fire

Abstract Prestressed hollow core slabs are one of the structural systems whose use has increased the most in recent years in Brazil due to its efficiency and versatility. They can be used in many types of structural systems, such as masonry, precast concrete, cast-in-place concrete and steel structures. However, there are few analytical models to evaluate the fire behavior of hollow core slabs. In a simplified way, the fire resistance is evaluated indirectly through the minimum distance of the surface in contact with fire to the reinforcement axis. In this paper, some numerical models in finite element software were developed to analyze the variation of temperature with fire exposure time of shallow hollow core slabs, focusing on the presence of voids in the transversal section of the slab. The 500 °C isotherm method applied to 20 cm high slabs confirmed the Standard Fire Resistance obtained from the tabular method. However, when applied to shallow prestressed hollow core slabs that are 16 cm high, the 500 °C isotherm method indicated that the Standard Fire Resistance of these slabs is lower than values obtained from tabular methods.

scholarly journals EVALUATION OF FIRE-PROTECTIVE ABILITY OF NEWLY CREATED FIRE-PROTECTIVE COATINGS OF STEEL STRUCTURES

2021 ◽  
pp. 79-88
Author(s):  
A. Kovalov ◽  
◽  
Y. Otrosh ◽  
V. Tomenko ◽  
O. Vasylyev ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Fire Resistance ◽  
Fire Protection ◽  
Experimental Studies ◽  
Fire Retardant ◽  
Steel Structures ◽  
Steel Plates ◽  
Thermal Calculation ◽  
Thermophysical Characteristics ◽  
Standard Temperature

Abstract. The results of the development of fire-retardant substances based on domestic materials to increase the fire resistance of fire-retardant steel structures are presented. New compositions of fire-retardant substances on the basis of domestic materials capable of swelling are developed. A series of experimental studies to determine the heating temperature of fire-resistant steel structures. For this purpose, samples of reduced size in the form of a steel plate with a flame retardant applied to the heating surface were used. Fire tests of fire-retardant steel plates coated with the developed fire-retardant substance forming a coating on the protected surface, in the conditions of their tests on the standard temperature of the fire using the installation to determine the fire-retardant ability of fire-retardant coatings. The results of experimental determination of temperature from an unheated surface of steel plates with a fire-retardant covering in the conditions of fire influence at a standard temperature mode of a fire are analyzed. Based on the obtained data (temperature in the furnace and from the unheated surface of steel plates with fire protection system) the solution of the inverse problems of thermal conductivity found thermophysical characteristics of fire protection coating (thermal conductivity and specific volume), which can be used for thermal calculation heating of fire-retardant steel structures at arbitrary fire temperatures. The thermophysical characteristics of the formed fire-retardant coating are substantiated to find the characteristics of the fire-retardant ability of the newly created fire-retardant coating and to ensure the fire resistance of fire-retardant steel structures. The efficiency of the developed fire-retardant coating for protection of steel structures is proved.

scholarly journals Refinement of the calculation model of vibrations for cylindrical supports of structures of oil and gas platforms during relocation

2021 ◽  
pp. 12-17
Author(s):  
О.Е. Сысоев ◽  
Е.О. Сысоев ◽  
А.Ю. Добрышкин
Keyword(s):  
Mathematical Model ◽  
Oil And Gas ◽  
Experimental Studies ◽  
Added Mass ◽  
Calculation Model ◽  
Offshore Platforms ◽  
Cylindrical Structures ◽  
External Forces ◽  
The Mathematical Model ◽  
Experimental And Theoretical Studies

В статье рассмотрена проблема предотвращения разрушения опор нефтегазовых морских платформ при передислокации. Цилиндрические конструкции опор нефтегазовых платформ очень чувствительны к динамическим воздействиям внешних сил, которые вызывают колебания конструкций и явление резонанса, особенно при передислокации. Цилиндрические опоры платформ также несут дополнительные массы (оборудование, антиледовый пояс и т.п.), которые оказывают значительное влияние на динамику работы оболочек. В статье уточнена математическая модель колебаний оболочек, несущих дополнительную массу, на основе теории Рейснера. Проведены экспериментальные исследования на уменьшенных моделях оболочек, проверки уточнённой математической модели, показано сравнение экспериментальных и теоретических исследований. Основное отличие скорректированной математической модели заключается в присутствии нового параметра, учитывающего влияния наличия малой дополнительной массы. Уточненнаяматематическая модель позволит более точно рассчитывать частоты колебаний конструкции в режиме online, и предотвращать возможные разрушения цилиндрических опор конструкций нефтегазовых платформ при передислокации. The article deals with the problem of preventing the destruction of the supports of oil and gas offshore platforms during relocation. Cylindrical structures of oil and gas platform supports are very sensitive to dynamic influences of external forces, which cause vibrations of structures and the phenomenon of resonance, especially during relocation. Cylindrical platform supports also carry attached masses (equipment, anti-ice belt, etc.), which have a significant impact on the dynamics of the shells operation. The article refines the mathematical model of vibrations of shells carrying the added mass on the basis of Reisner's theory. Experimental studies are carried out on reduced models of shells, verification of the refined mathematical model, a comparison of experimental and theoretical studies is shown. The main difference of the corrected mathematical model is the presence of a new parameter that takes into account the influence of the presence of a small added mass. The refined mathematical model will make it possible to more accurately calculate the vibration frequencies of the structure online, and prevent possible destruction of the cylindrical supports of the structures of oil and gas platforms during relocation.

Research heating of the steel i-beam rods with mineral wool coating under the conditions of standard temperature fire regime

2020 ◽  
pp. 116-126
Author(s):  
S.V. Pozdieiev ◽  
◽  
O.M. Nuianzin ◽  
S.O. Sidnei ◽  
A.Y. Novhorodchenko ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Fire Resistance ◽  
Fire Retardant ◽  
Steel Structure ◽  
Steel Structures ◽  
Mineral Wool ◽  
Fire Tests ◽  
Standard Temperature ◽  
Steel Columns ◽  
The Moment

In the article, experimental fire tests on establishing maximum fire resistance of the steel columns with fire-retardant mineral wool covering are analyzed. The scientific novelty of this study are the new method developed for manufacturing and shaping samples of the steel columns with fire-retardant mineral wool covering, and the method developed for conducting fire tests on establishing patterns of dependence of the moment when steel columns with the fire-retardant cladding lose their bearing capacity down to the limit. The subject of the study was an influence of design parameters of the fire-retardant cladding on the results of the estimated fire resistance of the steel columns under the influence of the standard fire temperature mode. The main task of the research described in this article was to determine a moment of the peak critical temperature of fire-retardant steel structure depending on the thickness of the mineral wool covering. The test results of samples of steel columns with different thickness of fire-retardant cladding based on mineral wool covering are also described in the article; the tests were carried out in accordance with the developed methodology of experimental studies. The repeatability of the time indicators of the bearing capacity loss by the tested samples of steel columns with fire-retardant cladding depending on the duration of the sample exposure to the action of the fire standard temperature is shown. The obtained research results will allow to create a mathematical model for predicting a dependence of the moment when a steel structure reaches its critical temperature depending on the thickness of the fire-retardant cladding. The constructed mathematical model can be considered as a scientific basis for the creation of new engineering methods of calculation for assessing fire resistance of the steel structures with fire-retardant mineral wool covering. These engineering and calculation methods allow improving the regulatory acts for designing of the fire-resistant steel structures.

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