CALCULATION METHODS OF HIGH TEMPERATURE DISTRIBUTION WITHIN STRUCTURAL COMPONENTS AND APPLICATION OF THESE METHODS TO FIRE RESISTANCE ASSESSMENT

Statyba ◽  
2001 ◽  
Vol 7 (5) ◽  
pp. 391-396 ◽  
Author(s):  
R. Mačiulaitis ◽  
K. Lukošius
2016 ◽  
Vol 820 ◽  
pp. 379-384
Author(s):  
Róbert Leško ◽  
Martin Lopušniak

Ability to resist of high temperature impacts during fire is not based exclusively on ignitability of building materials. At the present time, fire resistance is declared mainly through fire tests, but numerical procedures for the determination of fire resistance also represent an effective alternative in this field. Using calculation methods for the determination of ceiling structure fire resistance on the basis of timber is subject of the submitted paper. The main objective of this paper is to demonstrate the fact that timber, or products from it, are building materials capable to resist impacts of fully developed fire for the period of more than 60 minutes in spite of their flammability. Applicability of these results in selected countries of Europe can be seen from the list of requirements.


Author(s):  
Soo-yeon Seo ◽  
Jong-wook Lim ◽  
Su-hyun Jeong

AbstractTo figure out the change in the reinforcing effect of FRP system used for the retrofit of RC beam when it is exposed to high temperature, it is required to evaluate not only the behavior of the entire beam, but also the bond performance at anchorage zone through a bond test according to the increase of external temperature. Moreover, the study to find various fire-protection methods is necessary to prevent the epoxy from reaching the critical temperature during an exposure to high temperature. In this manner, the fire-resistance performances of externally bonded (EB) FRP and near-surface-mounted (NSM) FRP to concrete block were evaluated by high-temperature exposure tests after performing a fire-protection on the surface in this paper. Board-type insulation with mortar was considered for the fire-protection of FRP system. After the fire-protection of the FRPs bonded to concrete blocks, an increasing exposure temperature was applied to the specimens with keeping a constant shear bond stress between concrete and the FRP. Based on the result, the temperature when the bond strength of the FRP disappears was evaluated. In addition, a finite element analysis was performed to find a proper method for predicting the temperature variation of the epoxy which is fire-protected with board-type insulation during the increase of external temperature. As a result of the test, despite the same fire-protection, NSM specimens were able to resist 1.54–2.08 times higher temperature than EB specimens. In the design of fire-protection of FRP system with the board-type insulation, it is necessary to consider the transfer from sides as well as the face with FRP. If there is no insulation of FP boards on the sides, the epoxy easily reaches its critical temperature by the heat penetrated to the sides, and increasing the thickness of the FP board alone for the face with FRP does not increase the fire-resistance capacity. As a result of the FE analysis, the temperature variation at epoxy can be predicted using the analytical approach with the proper thermal properties of FP mortar and board.


Author(s):  
Si-Hwa Jeong ◽  
Min-Gu Won ◽  
Nam-Su Huh ◽  
Yun-Jae Kim ◽  
Young-Jin Oh ◽  
...  

In this paper, the thermal stress characteristics of the pipe-in-pipe (PIP) system under high temperature condition are analyzed. The PIP is a type of pipe applied in sodium-cooled faster reactor (SFR) and has a different geometry from a single pipe. In particular, under the high temperature condition of the SFR, the high thermal stress is generated due to the temperature gradient occurring between the inner pipe and outer pipe. To investigate the thermal stress characteristics, three cases are considered according to geometry of the support. The fully constrained support and intermediate support are considered for case 1 and 2, respectively. For case 3, both supports are applied to the actual curved pipe. The finite element (FE) analyses are performed in two steps for each case. Firstly, the heat transfer analysis is carried out considering the thermal conduction, convection and radiation conditions. From the heat transfer analysis, the temperature distribution results in the piping system are obtained. Secondly, the structural analysis is performed considering the temperature distribution results and boundary conditions. Finally, the effects of the geometric characteristics on the thermal stress in the PIP system are analyzed.


2013 ◽  
Vol 212 ◽  
pp. 127-132 ◽  
Author(s):  
Henryk Kania

In the paper the author presents the results of tests defining the characteristics of behaviour of Sandelin steel in the high-temperature galvanizing process. The growth kinetics of hot-dip zinc coatings on the substrate of 0.05% Si steel in the temperature range of 540-580°C has been established. The structure of the coatings and their phase composition have been developed and the chemical composition of structural components of the coating has be defined. It has been determined that the coating is composed of a compact layer δ1 and an area of a two-phase mixture of δ1 and Zn. The conducted tests confirmed the presence of phase Γ1 , which does not form a continuous layer but it forms individual precipitates which are irregular in shape. The growth kinetics of the coating indicates that an increase in temperature causes a decrease in the coating thickness, which might prove that dissolving processes prevailed over the processes of diffuse coating growth.


2011 ◽  
Vol 311-313 ◽  
pp. 953-956
Author(s):  
Hao Chen ◽  
Gang Tao

In order to study dynamic response of metal, this paper makes use of theoretical formula to investigate changes of temperature and grain size on steel target after the penetration of copper jet based on data gathered from the experiments. Deformed target penetrated by copper jet could be divided into superplastic deformation zone and normal deformation zone according to the different microstructure. Temperature distribution of each deformation zones is in turn calculated by two constitutive equations. The results indicate that areas with high temperature concentrate on the narrow zone near the penetrated channel. Then, the calculation of grain size conforms to the observation. It is obviously proven that the method used in this paper is trustworthy for calculating the changes of temperature and grain size of target caused by penetration.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1818
Author(s):  
Andrea Mura ◽  
Alessando Ricci ◽  
Giancarlo Canavese

Plastics are widely used in structural components where cyclic loads may cause fatigue failure. In particular, in some applications such as in vehicles, the working temperature may change and therefore the strength of the polymeric materials. In this work, the fatigue behavior of two thermoplastic materials (ABS and PC-ABS) at different temperatures has been investigated. In particular, three temperatures have been considered representing the working condition at room temperature, at low temperature (winter conditions), and high temperature (summer conditions and/or components close to the engine). Results show that high temperature have big impact on fatigue performance, while low temperatures may also have a slight positive effect.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xiujuan Li ◽  
Ruisong Guo ◽  
Xiaodong Qian

Under high temperature, aqueous film forming foam extinguishing agent has poor flame retardancy and low fire efficiency. In order to solve this problem, talc was introduced into foam to form composite foam. The fire resistance and fire extinguishing properties of the composite foam were studied. The results showed that talc composite foam had good flame retardant resistance. when the concentration of talc reached 40 g/100 ml, the 50% liquid separation time of the composite foam was 21.1 min. The fuel burning in the anti burning tank did not ignite the gasoline in the oil pan, and burned out at 51.5 min. It was related to the structure of composite foam and the properties of talc. Due to the introduction of talc, the viscosity of the composite foam increased. The network structure of composite foam was important to the improved stability of foam. Talc powder formed a dense layer covering the oil surface, which effectively isolated the oil from the air.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1358-1362
Author(s):  
Jin Sheng Han ◽  
Hao Ran Liu ◽  
Shu Ping Cong

The fire resistance of concrete filled steel tubular column is usually obtained by the numerical analysis method, which is difficult to operate and not convenient in the actual civil engineering. So it is necessary to study the simplified calculation method. A large number of numerical simulation results of the temperature distribution of the section and the bearing capacity at high temperature of the concrete filled steel tubular columns are analyzed. The influences of secondary parameters are simplified. The simplified calculation method at 150 min and 180 min for the bearing capacity at high temperature of concrete filled steel tubular columns subjected to axial compression and fire is presented on the basis of comprehensive analysis of the numerical calculation results. The calculation results can be used as the basis to judge the fire resistance. It is shown by the comparison with the experimental results that the precision of the simplified calculation method can meet the requirements of engineering application.


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