Life-Cycle Prediction
Yinusa Ahmed; Sobamowo Gbeminiyi
Abstract
Iron micro-particles when eject to the atmosphere from industries, factory and production enterprises pollute the atmosphere and generally affect the respiratory system. This paper presents a solution to such transient problem analytically by employing Variation of Parameter Method (VPM). For proper ...
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Iron micro-particles when eject to the atmosphere from industries, factory and production enterprises pollute the atmosphere and generally affect the respiratory system. This paper presents a solution to such transient problem analytically by employing Variation of Parameter Method (VPM). For proper understanding of the problem chemistry and associated time of burning, the parameters involved are meticulously studied. The radiation property of the iron particle at high temperature as well as the impact of this temperature level on density are considered by incorporating radiation and linear micro particles density variation in the governing model. The obtained exact solution using VPM is verified with Runge-Kutta and also compared with the results of other works. Furthermore, error analysis is performed and discussed. The obtained result shows how the surrounding temperature and the heat realization term continue to influence combustible temperature history until an asymptotic behaviour is attained. It is envisaged that the present study will gain application in trying to annul some of the challenges the industries and firms have to overcome on combustion of solid combustibles like iron particles and also in the optimization of different particles burning time.
Ajibola Quadri
Abstract
Nowadays assessment of fatigue and reliability of structures have increased dramatically. This is confirmed by the recommendations of the standards and constitutive model of concrete in which the rules and requirements to ensure safety, serviceability and durability of the structure are stated. This ...
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Nowadays assessment of fatigue and reliability of structures have increased dramatically. This is confirmed by the recommendations of the standards and constitutive model of concrete in which the rules and requirements to ensure safety, serviceability and durability of the structure are stated. This study is directed to the reliability assessment of reinforced concrete column and fatigue comparison of (BS:8110, 1997) and Eurocode 2 (EN:2, 2004) ultimate limit state requirements on nominal eccentricity of short column resisting moments and forces. The column was modeled as one end fixed to resist moment reaction and free at the other end. It was then examined on fatigue and probabilistically assessed with the variables relating to the uncertainty loading conditions. The First-Order Reliability Method (FORM 5) encoded in CalREL was employed to estimate the implied probability of failure by varying load ratio and reinforcement ratio. And was verified with numerical simulation on CONCRETE MODEL OF 3 Dimension (COM 3). The results obtained have shown that the column assessed lost its flexural and shear carrying capacity gradually as the percentage load increased especially at the joint. Reinforced concrete column’s performance may be dependent on the applied load and could fail if it carries a lot more than the designed loads. It is therefore necessary to perform fatigue investigation to double check the resistant capacity of the column.
System Reliability
Ashraf Elfasakhany
Abstract
Incorrect tire pressure reduces vehicle performance, braking effectiveness, system control, and a ride comfort. Tire pressure checking framework (TPCF) is a system framework applied for checking tire pressure. This study aim at summarizing early work for the tire pressure checking framework including ...
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Incorrect tire pressure reduces vehicle performance, braking effectiveness, system control, and a ride comfort. Tire pressure checking framework (TPCF) is a system framework applied for checking tire pressure. This study aim at summarizing early work for the tire pressure checking framework including early different methods. Direct and indirect tire pressure checking frameworks are discussed and a comparison between both methods is summarized. A development of tire pressure checking framework is presented. Risks of the low/high tire pressures are discussed. Operating the tire at lower and/or higher pressure than the specified one can cause several severe problems. Direct TPCF uses physical sensors, however, the indirect TPCF uses velocity and vibration sensors to monitor the tire pressure. Direct TPCF framework method is more accurate than the indirect one; however, the direct showed some problems related to battery life and framework costs. The indirect needs calibration/adjustment by the drivers, and cannot realize the simultaneous loss of pressure from more than one tire in time.
Probabilistic Design Approaches
A. Mustapha; Olugbenga Abejide
Abstract
The profound changes in engineering over the last few decades were reflected by ideas of uncertainty recognized in engineering today. Civil engineering structures like steel transmission poles are to be designed for loads created by environmental actions such as wind, snow and earthquake, but these actions ...
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The profound changes in engineering over the last few decades were reflected by ideas of uncertainty recognized in engineering today. Civil engineering structures like steel transmission poles are to be designed for loads created by environmental actions such as wind, snow and earthquake, but these actions are exceptionally uncertain in their manifestations as one is required to quantify the risks and benefits involved. The subject of structural reliability offers a rational framework to quantify uncertainties mathematically. This study presents a probabilistic assessment of the strength of steel poles in service, the resistance of the steel poles, ultimate strength of steel, section modulus, cross sectional dimensions of the poles, distance at which the load acts on the pole and the magnitude of the load acting on the pole are treated as random variables, which can be significantly influenced by time and location. The study has been carried out to determine the structural safety levels of electric distribution steel poles under uncertain loadings using First Order Reliability Method (FORM) in MATLAB with FERUM Version 4.0. The reliability analyses in MATLAB gave lower values of reliability index, (1.4802E+00) and probability of failure (6.9407E-02) for moment failure mode, while higher values of (2.339E+01 and 5.1245E+01) were obtained respectively for deflection and shear failures, with negligible values of 0.100E-10. The effect of variation of parameters like thickness, diameters and length of steel poles were also studied, which indicates that the thickness, diameters and length significantly affects the strength of steel poles.
Uncertainties Evaluation of Loads and Loading Conditions
Farshad Dorri; Hooman Ghasemi; Andrzej Nowak
Abstract
Finding an appropriate system to absorb the intended energy of the earthquake is of great importance in seismic region. The eccentric bracing frame (EBF) is one of the structural systems that reveal proper behavior during earthquakes phenomenon. In doing so, design codes attempt to optimize EBF seismic ...
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Finding an appropriate system to absorb the intended energy of the earthquake is of great importance in seismic region. The eccentric bracing frame (EBF) is one of the structural systems that reveal proper behavior during earthquakes phenomenon. In doing so, design codes attempt to optimize EBF seismic behave to avoid failure of the earthquake regarding a set of the criteria. Indeed, the dynamic nonlinear approaches are the most powerful methods which solve the motion equations based on the time history of the ground motion. However, the dynamic nonlinear methods require a rigorous effort to nail the structural responses. Therefore, there is a need to develop a simplified approach such a pushover method which is based on the non-linear static analysis. The main attempt of this research is to present a simplified push overload pattern for EBF system to sufficiently divulge the structural performance subjected to the seismic loadings. In this investigation, three models of the middle rise and tall rise, 10, 20, 30 stories of buildings are considered, which are designed according to the available codes. Accordingly, several different load patterns are developed. The idea behind of each proposed load patterns inspired by the deflection of a rod subjected to the flame. Herein, the meaning of the flame refers to the region of the structures which is subjected to the plastic hinges.
Structural Simulation
K.K. Kiran; Jagadish Kori
Abstract
Designer of military and high-security facilities, planner, architects and engineers throughout the world are much concerned against a blast load on structures. Blast load is a human hazard occurring in the world, due to terrorist, chemical explosives, mining area, an accident, and so on. Blast load ...
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Designer of military and high-security facilities, planner, architects and engineers throughout the world are much concerned against a blast load on structures. Blast load is a human hazard occurring in the world, due to terrorist, chemical explosives, mining area, an accident, and so on. Blast load is an unpredictable load occurring. The blast load occurs in a few seconds. The blast load does not only lead to structural but also take the life of occupations. In this study five – storey unsymmetrical structures exposed to blast load are considered. The three different control devices are considered such as cladding material, base isolation with lead rubber bearing (LRB) and MR Damper. Cladding material will absorb energy after the severe pressure release from the blast and then transfer less amount of energy to the structures. Base isolations with lead rubber bearing not only absorb energy but also increase the stiffness of the structure. Among the different devices’ MR Damper plays a vital role reduce the considerable amount of responses.
