Components under fatigue loading have significant amounts of scatter and inconsistency considered in fatigue failure data. Due to uncertainties in predicting component fatigue life, probabilistic approaches were to quantify the influence of uncertainties on the fatigue life. However, computation time associated with the commonly used Monte Carlo simulation can be prohibitive during design stage assessments. Therefore, the purpose of the current work was to demonstrate the use of efficient probabilistic methods, as alternatives to Monte Carlo method, to accurately predict fatigue lives for Aluminum 6061-T6 sheets. Based on experimentally determined of stress-life distributions, predicted distributions of fatigue life agreed closely with replicate experimental test results. The study showed that with significantly less computational time, there is a very good agreement for advanced mean value (AMV) and the first order reliability method (FORM) with Monte Carlo. However, the mean-value (MV) method was less accurate in tail regions that indicates poor life prediction. The sensitivity analysis showed that S-N slope parameters (a and b) had insignificant contributions to the scatter in fatigue life compared to the dynamic loading and component geometries.

In this paper, a series of experiments were conducted including testing of the capabilities of composite material as an energy absorber. Composite plate specimens with different corrugation profile have been fabricated and tested under the same condition. The corrugated profiles are: sinusoidal, triangle, and square shape. All these specimens were made of glass fibers using hand layup technique. The corrugated plates are subjected to quasi-static compression load. In addition to that same kind of tested specimens have been modeled and tested using Finite Element Method (FEM). Theoretical and experimental results in a form of energy absorption and specific energy have been recorded. It is found that results of theoretical and experimental tests are almost exactly identical. It has been observed that composite plate with square profile recorded the highest energy absorption and specific energy for theoretical as well as experimental tests.

Monitoring smart grids and detecting faults in such huge networks has recently become an active area of research. The huge amount of data transferred from the measurement units to the control center makes it difficult to detect faults in a reasonable amount of time. Some existing methods have been investigated and tested on many IEEE models such as wavelet transform, principal component analysis (PCA) to extract the abnormal behavior of signals under monitoring [1]. However, such techniques pose difficulties in detecting different faults properly. In this paper, the multidimensional scaling (MDS) is investigated as an alternative technique for reducing the dimensionality of the data to lower dimensions, while maintaining the necessary information needed for fault detection. MDS is then used to investigate the behavior of some IEEE models under different types of faults in order to detect and locate the faulty bus bars.

This paper is devoted to study the effect of crashing of vehicles with concrete blocks that placed around lighting poles. Unexpected dangers takes place if crashing occurs. It may cause death of the driver and passengers, or severe injuries. In order to minimize or eliminate this risk, a system made of corrugated composite material plates have been designed to replace the concrete blocks around lighting poles. This system is made of reinforced fiber glass and it is modeled to crash with a model of car exactly similar to the real one, forming a simulation of car accident. Modeling process takes place using Finite Element Analysis (FEA). ANSYS software utilized for this purpose. Simulation was performed at three different speeds of the vehicle. Results obtained have been recorded in a form of deformed mesh, and contours. The results proved that the new designed system is working perfectly and it has the ability to absorb impact energy caused by car accident. Therefore, by using composite material instead of concrete, risk of death and injuries will minimized or completely eliminated.

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ABSTRACT

Swirl stabilised combustion is one of the most widely used techniques for flame stabilisation in gas turbine combustors. Lean premixed combustion systems allow the reduction of NOx coupled with fair flame stability. The swirl mechanism produces an aerodynamic region known as central recirculation zone (CRZ) providing a low velocity region where the flame speed matches the flow velocity, thus anchoring the flame whilst serving to recycle heat and active chemical species to the root of the f

ormer. Another beneficial feature of the CRZ is the enhancement of the mixing in and around this region. However, the mixing and stabilisation processes inside of this zone have shown to be extremely complex. The level of swirl, burner outlet configuration and combustor expansion are very important variables that define the features of the CRZ.

Therefore, in this paper swirling flame dynamics are investigated using computational fluid dynamics (CFD) with commercial software (ANSYS). A new generic swirl burner operated under lean-premixed conditions was modelled. A variety of nozzles were analysed using several gaseous blends at a constant power output. The investigation was based on recognising the size and strength of the central recirculation zones. The dimensions and turbulence of the Central Recirculation Zone were measured and correlated to previous experiments. The results show how the strength and size of the recirculation zone are highly influenced by the blend and infer that it is governed by both the shear layer surrounding the Central Recirculation Zones (CRZ) and the gas composition

The main objective of this paper is to study the effect of replacing

the internal casing of water boiler that made of metallic material by a

similar one made of composite materials. An intensive theoretical study

have been carried out on domestic electrical water boiler using modeling

technique. Analysis and modeling process was performed using Finite

Element Method. Thermal conductivity which is the main parameter

affecting heat transfer has been tested for composite material as well as

for metallic materials. Results showed that it is more convenient to use

composite material for inner case of water boiler instead of metallic

material. Composite materials are lighter than metallic material, much

safer (eliminate possibility of electrical shock), and it hasn't corrosion

problems. It is found that it is possible to replace the internal case of

water boiler made of metallic material with a wall thickness of 7 mm by

an equivalent composite material case made of glass fiber with the same

thickness. Obtained results showed that seven layers of composite

materials forming similar wall thickness is an optimum case with respect

of heat transfer and thermal conductivity.

The aim of the present work is to guarantee the safety of the Tajoura Nuclear Research Centre's reactor (TNRC) as a result of a hypothetical Loss of Coolant Accident (LOCA). Transient evaluation of the postulated LOCA in primary coolant system is executed using PARET/ANL Code. A large break (LB-LOCA) is assumed and the location of the rupture is supposed to be 4.32m above the core. Therefore, the core is covered with water and natural convection mainly provides the cooling after the accident. The simulations are performed at the operating power of the reactor equals to 9 MW and for 180 s after SCRAM. The results show that the reactor is safe since the clad surface temperature (95.23 °C) at the hottest channel is lower than the maximum permitted value this means the existence of sufficient water above the core to cool it by the natural convection.

A B S T R A C T

Swirl stabilised combustion is one of the most successful technologies for flame stabilisation in gas turbine combustors. Lean premixed combustion systems allow the reduction of NOx coupled with fair flame stability. The swirl mechanism produces an aerodynamic region known as central recirculation zone (CRZ) providing a low velocity

region where the flame speed matches the flow velocity, thus anchoring the flame whilst serving to recycle heat and active chemical species to the root of the former. Another beneficial feature of the CRZ is the enhancement of the mixing in and around this region. However, the mixing and stabilisation processes inside of this zone have shown to be extremely complex. The level of swirl, burner outlet configuration and combustor expansion are very important variables that define the features of the CRZ. The complex fluid dynamics and lean conditions pose a problem for stabilization of the flame. The

problem is even more acute when alternative fuels are used for flexible operation.

Therefore, in this paper swirling flame dynamics are investigated using computational fluid dynamics (CFD) with commercial software (ANSYS). A new generic swirl burner operated under lean-premixed conditions was modelled. A variety of nozzles were analysed using isothermal case to recognize the the behavers of swirl.

The investigation was based on recognising the size and strength of the central recirculation zones. The dimensions and turbulence of the Central Recirculation Zone were measured and correlated to previous experiments. The results show how the strength and size of the recirculation zone are highly influenced by both the shear layer surrounding the Central

Recirculation Zones (CRZ) and outlet configurations.