The consequences of a flashover fire in a room adjacent to a double-skin façade were studied on a fire model with Computational Fluid Dynamics (CFD) and physical experiments. The CFD package Fire Dynamics Simulator (FDS) was selected. CFD-FDS predictions on smoke filling and exhaust were justified by quality experimental data on smoke exhaust in a big hall fire, and field measurement from hot smoke tests in Hong Kong. FSD was applied to study how hot gas from a flashover fire in an adjacent room spread to the cavity of the double-skin façades. Detailed simulations were carried out to understand the fire-induced aerodynamics in the façade cavity of heights up to 15 m. Three possible fire hazards on having higher air temperatures adjacent to the interior glass pane then the exterior pane, vertical channel flow of hot smoke and upward flame, and fire sources jumping up, were identified from this study. To better understand the fire hazards of double-skin façades, full-scale burning tests on two specially designed rigs for studying the identified fire scenario were carried out in a remote area of Northeast China. The hazards in the façade cavity posed by relative air temperature differences between interior and exterior panes, and spreading up along the cavity were confirmed. The fire source jumping-up scenario associated with glass façade buildings was well demonstrated. Aprori design in a refuge floor is proposed to prevent fire spread along the interior façade panes. Further, hot gases would be diverted to act at the exterior pane. Breaking the exterior pane can ventilate flame and smoke out of the façade cavity. The proposal was supported firstly by CFD-FDS simulations and ten full-scale burning tests with gasoline pool fires.

No description available.

No description available.

This thesis is concerned with: Assessing the usefulness of spatial acoustics to navigation and testing the changing accuracy of that ability with changing stimuli, room acoustics and visual ability. The results of this study have the potential to inform good building and acoustic design, which could improve navigation, within buildings, for Visually Impaired People. This thesis describes the spatial hearing mechanism, termed .localisation or lateralization when using headphones and an experiment to test the effect of the hypothesised variables. These include sound stimuli type, room reverberation RT60 (2 • 0.5 second$) and visual impairment. The experiment. uses two sample groups of visually impaired persons (VIP) and non-visually impaired persons (NVIP). The results indicate that lateralization ability does not differ at a statistically significant level with visual ability; that lateralization using signals with strong Onset disparities is independent ofRT6O but not of Early Reflections; that lateralization using interaural level and timing differences is dependent on RT60 and; a person's subjective opinion of their ability or suitability of listening environment does not relate to objective performance. Lastly, it is hypothesised that: Onset Disparities constitute more reliable auditory information than ,. interaural level or timing differences and that they are thereby treated differently by the neurological system; That late reverberant energy will affect lateralization, only when there is an absence of strong directional cues and in these instances a subject's perception of a sound's direction may also be influenced by other factors such as, the direction of visual attention, and; That the ability of a subject to determine the direction of a sound by hearing is a function of training rather than visual ability.

No description available.

In order to reduce energy usage for heating, conventional practices suggests that, a building must be airtight and more insulation must be used. This has led in the past to inadequately ventilated buildings and the accumulation of high levels of volatile organic compounds and other pollutants indoors, contributing to sick building syndrome. Dynamic insulation, although a fairly new concept, is attracting attention as a means of reducing energy consumption in building while at the same time, improving indoor air quality. This thesi6 investigates and develops procedures and ,.' mix formulations for producing a concrete-based dynamic insulation material, also known as 'breathable concrete'. When used as a building envelope this special concrete must have: (i) sufficient strength to carry its 'own weight, (ii) be sufficiently air permeable as a ventilation source when subject to 5-10 Pa diff~rential pressure across the inlier and outer surface, and (iii) have low static thermal conductivity. The research investigated (a) the shape and size of aggregate, (b) quantity of cement, ' (c) the quantity of water and other admixtures, and their relevant role in the design of breathable concrete. Pre-cast concrete cylinders were made possessing the necessary target permeability of 0.05 m2/pa hr and compressive strength of> 'lOMPa. Various properties of the concrete, such as permeability, porosity, compressive strength, thermal conductivity and dynamic V-value, were determined. In conjunction with the experimentS, four experimental apparatus were developed and modified during this investigation - two for the determination ofporosity and permeability of concrete, one for determining the static thermal conductivity of concrete and one for determination of the steady- state, one-dimensional heat transfer properties. A number of theoretical 'and empirical models have also been developed for predicting the static and especially, the dynamic behaviour of breathable concrete. The results confirm that pre-cast breathable concrete blocks can be used as a sustainable building material . but further optimisation is desired; suggestions are made for further work.

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Various possible maintenance strategies could be made up to achieve maintenance objectives such as safety, durability, reliability and the operating economy of machines. Utilization of a plant condition monitoring programme in an industry which has no background on condition-based maintenance requires an appropriate machinery condition monitoring methodology adapting the traditional maintenance system with an efficient maintenance programme. In this research project a plant survey and feasibility study has been implemented through a field study and a condition monitoring pilot study in order to evaluate the condition of machinery under study and the efficiency of an existing maintenance system. Data obtained from the field study were analysed and critical failure problems and the major environmental and operational factors contributing to these failures have been highlighted. A comprehensive oil analysis programme has been carried out on more than one thousand oil samples which had been taken from five major components of construction machinery, i.e., engines, transmission, hydraulic systems, differential and final drive units. The analytical results have been statistically analysed. Initial monitoring guide lines for establishing a condition monitoring programme have been created and the effect of factors, such as operational environment, machine type and make, on analytical results have been investigated. Correlation between various oil analysis readings which could provide useful information for diagnostic purposes have been discussed. The efficiency of an oil analysis condition monitoring programme has also been investigated by comparing the results of machinery which have and have not been continuously monitored. In this work, a simple and quick wear debris test technique (Bottle Method) has been developed for both laboratory and field orientated monitoring programmes. A modified procedure was also developed for evaluating the state and severity of wear in a component. This technique could also be used in field or laboratory monitoring programmes.

The main objective of this research is to develop a numerical model for the analysis of frost damage to masonry and implement it in a program for 3-dimensional analyses of masonry structures using the finite element method. It is shown that the standard FE approach in analysing masonry structures is not economical, so a homogenization technique was used to substitute composite masonry material with an equivalent homogeneous one. Parametric studies of relationships of property between constituents and the equivalent material are presented together with validation of the procedure. Masonry, or its constituents, is treated as a brittle material with a tensile cut-of failure criterion. Again, in order to achieve more computational efficiency, homogenization technique is used to represent cracked material. A set of freeze-thaw tests are described which are important in detecting the most influential factors controlling frost durability of masonry. Models of frost action are investigated on a micro scale - scale of individual pores. A stochastic network model is developed with an aim to investigate permeability characteristics of the porous material. The results of these calculations are used in providing information necessary to calculate stress due to the frost action. Typical examples of frost damage to masonry are simulated showing good agreement with the expected results. The following conclusions are drawn: * The major cause of damage to masonry is the expansion of water on its phase change from a fluid to a solid phase in the 'sealed container' conditions. * Micro structural properties of the material are the most important single factor in deciding the amount of internal loading on the material matrix caused by ice formation. In order to calculate this loading simulation of the process on the micro scale is required. * It is confirmed that a high fraction of small pores in the porous structure causes higher level of frost susceptibility.

Weight reduction of the automotive structure can be enhanced by using continuous joining techniques as a means of assembly. Continuous joints increase structural rigidity and thereby overcome the loss in stiffness associated with the higher strength but thinner steels proposed for use by the automotive industry. The comparison of continuously joined structures with conventionally joined (spot welded) structures will help to determine the potential weight reduction of the automotive structure. The effects of joining technique, sheet thickness, steel strength, section area, section design and level of end constraint on the torsional properties of box sections were determined experimentally using factorial design techniques. The joining techniques investigated included adhesive bonding, weldbonding, laser welding and spot welding. Finite element models were developed using ANSYS and ABAQUS and were used to extend the scope of the test programme. T-joints, comprised of two box sections jointed at right angles, were tested experimentally using factorial design techniques, and were also analysed numerically. Joining technique, sheet thickness and section area had the most influence on box section torsional stiffness. A 44% and 10% weight reduction was estimated through downgauging and area reduction, respectively, in conjunction with the substitution of spot welding with adhesive bonding. Joint eccentricity was also identified as a factor which influenced the torsional stiffness of box sections and could also be related to weight reduction. The effect of joint eccentricity at the connection of T-joints was shown to have a major effect on the torsional stiffness and strength of T-joints. A numerical comparison between a T shaped component from a BIW with a regular T-joint was conducted. The results confirmed the validity of using simplified test pieces to represent more complex components.