DSpaceCRIS@UNITENhttp://dspace.uniten.edu.my/jspuiThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Thu, 15 Nov 2018 04:06:12 GMT2018-11-15T04:06:12Z5071Safety of nuclear reactors part A: Unsteady state temperature history mathematical modelhttp://dspace.uniten.edu.my/jspui/handle/123456789/8587Title: Safety of nuclear reactors part A: Unsteady state temperature history mathematical model
Authors: El-Shayeb, M.; Yusoff, M.Z.; Boosroh, M.H.; Bondok, A.; Ideris, F.; Hassan, S.H.A.
Abstract: A nuclear reactor structure under abnormal operations of near meltdown will be exposed to a tremendous amount of heat flux in addition to the stress field applied under normal operation. Temperature encountered in such case is assumed to be beyond 1000°C. A mathematical model has been developed for the fire resistance calculation of a concrete-filled square steel column with respect to its temperature history. Effects due to nuclear radiation and mechanical vibrations will be explored in a later future model. The temperature rise in each element can be derived from its heat balance by applying the parabolic unsteady state, partial differential equation and numerical solution into the steel region. Calculation of the temperature of the elementary regions needs to satisfy the symmetry conditions and the relevant material properties. The developed mathematical model is capable to predict the temperature history in the column and on the surface with respect to time.
Thu, 01 Jan 2004 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/85872004-01-01T00:00:00ZSafety of nuclear reactors part B: Unsteady-state strength mathematical modelhttp://dspace.uniten.edu.my/jspui/handle/123456789/8586Title: Safety of nuclear reactors part B: Unsteady-state strength mathematical model
Authors: El-Shayeb, M.; Yusoff, M.Z.; Bondok, A.; Roseli, A.; Ideris, F.; Hassan, S.H.A.
Abstract: The significant mechanical properties that determine the strength of concrete-filled square steel columns are compressive strength, modulus of elasticity, ultimate strain of the concrete, yield strength and modulus of elasticity of the steel. A survey of the literature shows that the variation of these properties with temperature is influenced by many factors. The compressive strength of concrete at elevated temperature is affected by the rate and duration of heating, the size and shape of the test specimen and the loading during the heating. During exposure to fire the strength of the column decreases with the duration of exposure. The strength of the column can be calculated by a method based on load-deflection analysis which in turn is based on a stress-strain analysis of cross-sections. A mathematical model describing the behavior of concrete-filled square steel column structures under load and heat has been thoroughly examined in this paper. The main goals of this model are to study the structure member characteristics (temperature, deformation and strength) under excessive heat conditions and to study the possibility of increasing the endurance time by changing the column composite structure.
Thu, 01 Jan 2004 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/85862004-01-01T00:00:00ZSafety of nuclear reactors part A: Unsteady state temperature history mathematical modelhttp://dspace.uniten.edu.my/jspui/handle/123456789/8685Title: Safety of nuclear reactors part A: Unsteady state temperature history mathematical model
Authors: El-Shayeb, M.; Yusoff, M.Z.; Boosroh, M.H.; Bondok, A.; Ideris, F.; Hassan, S.H.A.
Abstract: A nuclear reactor structure under abnormal operations of near meltdown will be exposed to a tremendous amount of heat flux in addition to the stress field applied under normal operation. Temperature encountered in such case is assumed to be beyond 1000°C. A mathematical model has been developed for the fire resistance calculation of a concrete-filled square steel column with respect to its temperature history. Effects due to nuclear radiation and mechanical vibrations will be explored in a later future model. The temperature rise in each element can be derived from its heat balance by applying the parabolic unsteady state, partial differential equation and numerical solution into the steel region. Calculation of the temperature of the elementary regions needs to satisfy the symmetry conditions and the relevant material properties. The developed mathematical model is capable to predict the temperature history in the column and on the surface with respect to time.
Thu, 01 Jan 2004 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/86852004-01-01T00:00:00ZSafety of nuclear reactors part B: Unsteady-state strength mathematical modelhttp://dspace.uniten.edu.my/jspui/handle/123456789/8684Title: Safety of nuclear reactors part B: Unsteady-state strength mathematical model
Authors: El-Shayeb, M.; Yusoff, M.Z.; Bondok, A.; Roseli, A.; Ideris, F.; Hassan, S.H.A.
Abstract: The significant mechanical properties that determine the strength of concrete-filled square steel columns are compressive strength, modulus of elasticity, ultimate strain of the concrete, yield strength and modulus of elasticity of the steel. A survey of the literature shows that the variation of these properties with temperature is influenced by many factors. The compressive strength of concrete at elevated temperature is affected by the rate and duration of heating, the size and shape of the test specimen and the loading during the heating. During exposure to fire the strength of the column decreases with the duration of exposure. The strength of the column can be calculated by a method based on load-deflection analysis which in turn is based on a stress-strain analysis of cross-sections. A mathematical model describing the behavior of concrete-filled square steel column structures under load and heat has been thoroughly examined in this paper. The main goals of this model are to study the structure member characteristics (temperature, deformation and strength) under excessive heat conditions and to study the possibility of increasing the endurance time by changing the column composite structure.
Thu, 01 Jan 2004 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/86842004-01-01T00:00:00ZUtilization of numerical techniques to predict the thermal behavior of wood column subjected to fire. Part A: Using finite element methods to develop mathematical model for wood columnhttp://dspace.uniten.edu.my/jspui/handle/123456789/10175Title: Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire. Part A: Using finite element methods to develop mathematical model for wood column
Authors: Elshayeb, M.; Rashid Ab Malik, A.; Ideris, F.; Hari, Z.; Ab Razak, N.; Siang, J.E.L.; Anuar, Z.
Abstract: The mathematical model to predict the temperature history for wood column is needed in order to determine its fire resistance when exposed to fire. In this paper, an intelligent methodology called Finite Element Method (FEM) of performing analysis for the square and circular wood columns by virtually or artificially developing a temperature history mathematical model. Numerical simulation model has been developed for the wood column by using two-dimensional mathematical model. The two-dimensional mathematical model was developed by using Galerkin's Weighted Residual technique. This model focuses on the regional material of the wood column for describing its thermal behavior. When the temperature history in a column and relevant materials properties are known, the strength of the column can be calculated at any time during fire. Therefore, the development of the temperature history mathematical model is a must before any further study to be carried out for the wood columns. The flow of convection will result in minimal increase in the rate of heat energy reaching the column core. The analysis shows that the temperature of the column increases with respect to the duration of exposure to fire.
Sun, 01 Jan 2006 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101752006-01-01T00:00:00ZUtilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part C: Sensitivity analysishttp://dspace.uniten.edu.my/jspui/handle/123456789/10173Title: Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part C: Sensitivity analysis
Authors: Elshayeb, M.; Malik, A.R.A.; Ideris, F.; Hari, Z.; Razak, N.A.; Siang, J.E.L.; Anuar, Z.
Abstract: Theoretical studies have been carried out to predict the fire resistance of different configuration of wood columns as done in Part A and Part B of this set of research papers. This theoretical study is a continuation of previous studies, which were carried out at National Research Council Canada. Mathematical models to calculate the temperatures, deformations and fire resistance of the columns have been developed for Part A and Part B. Calculated results are compared with those measured in several tests. The results indicated that the model is capable of predicting the fire resistance of wood columns with an excellent accuracy. By using the model, the fire resistance of wood columns can be evaluated for any value of the significant parameters such as load, physical dimensions, mechanical properties and even the chemical properties without the necessity of experiment. This research paper carried out sensitivity analysis of a square column at elevated temperature in order to know the effect of some parameters towards the mechanical strength of the column. The parameters that have been studied are initial moisture content, Young's modulus, initial compression stress, specific gravity, thermal conductivity and the physical dimension of the column cross section. Both of the temperature history versus time for the selected elements and the fire resistance has been analyzed using existing results. All the analyses have been carried out for the square cross-section under axial load 1380 kN.
Sun, 01 Jan 2006 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101732006-01-01T00:00:00ZUtilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part B: Analysis of column temperature and fire resistancehttp://dspace.uniten.edu.my/jspui/handle/123456789/10174Title: Utilization of numerical techniques to predict the thermal behavior of wood column subjected to fire part B: Analysis of column temperature and fire resistance
Authors: Elshayeb, M.; Malik, A.R.A.; Ideris, F.; Hari, Z.; Razak, N.A.; Siang, J.E.L.; Anuar, Z.
Abstract: Mathematical models of Part A [1] are used to calculate the temperatures, deformations and fire resistance of rectangular, hexagonal, octagonal and I-cross section columns for the purpose of Part B. In this paper the comparison among the configurations of the column has been carried out to predict the temperature history for the column elements for preventing the spread of fire and prolonging the structural time collapse. The columns are varied in section size, among them are the rectangular, hexagonal, octagonal and I-cross section column of Keruing timber. The developed mathematical models defined the failure point as the point which the column can no longer support the applied load. From the comparison, the I-cross section column is the worst configuration than the other configuration.
Sun, 01 Jan 2006 00:00:00 GMThttp://dspace.uniten.edu.my/jspui/handle/123456789/101742006-01-01T00:00:00Z