This work deals with the preparation, thermo-hydraulic characterisation, and performance analysis of silica gel coated highly conductive surface enhancing structures to be used as tube inserts in a prototype of an innovative water-cooled sorption rotor. The candidate inserts under investigation comprise highly porous aluminium foam inserts, twisted-in wire brushes, and flocked structures, that are investigated for their flow impedance, heat transfer performance, and cyclic dehumidification performance. The conducted analysis comprises experimental testing of insert specific pressure drop and heat transfer performance in a purpose built test rig, that led to the preselection of the foam structures and a twisted-in aluminium wire brush insert for desiccant coating and further investigation. Cyclic heat and mass transfer tests were performed in a purpose-built small-scale test rig, that simulated the dehumidification process of a desiccant rotor with and without employing water-cooling. The experimental analysis is complemented by a numerical investigation of the cyclic heat and mass transfer performance of the brush and metal foam type structures, modelled as two-dimensionally axis-symmetric porous media. The geometry based functions of the insert specific flow characteristics are derived from two- and three-dimensional pore scale computational fluid dynamics models, that are calibrated against experimental data. The validity of fundamental modelling assumptions was confirmed by a decent agreement between numerical and experimental steady-state heat transfer results. The heat and mass transfer investigation showed that the investigated structures were capable of effectively removing heat during the dehumidification half-cycle. The thermal mass was shown to be a critical design parameter in achieving acceptable dehumidification performance.

The objectivc of this research was to determine the in-plane shear stiffness and strength of a reinforced concrete sprecimen, which had first been cracked in uniaxial tension. This information could then lead to a more accurate analysis or reinforced concrete structures using the finite clement method. Tests were devised that enabled the effects of aggregate interlock and of dowel action in slab type specimens to be studied independently. As the aggregate interlock and dowel action specimens were similar and were loaded in the same way, a direct comparison of the test results could be made. The composite effects of aggregate interlock and dowel action were then studied by applying the same shear loading to cracked reinforced concrete specimens. The shear stiffness and strength due to aggregate interlock were typically found to be two to four times as great as those due to dowel action. It was also observed that the crack in the aggregate interlock tests tended to widen as shear slip occurred. This is an effect which has received very little attention in the past. The stiffness normal to the crack that restrains crack widening, and the initial crack width were both observed to have a significant influcnce on the aggregate interlock shear stiffness. The behaviour of the reinforced concrete specimens was similar to that which was expected from the results of the dowel action and aggregate interlock tests, if the additional effects of local bond were LikclI into consideration. Several analytical models of the micro mechanisms of shear resistance within the specimens were studied and formulae were derived to predict their behaviour. A matrix equation for the material properties for cracked concrete was derived and used in a finite clement analysis in an attempt to model the behaviour of a reinforced concrete structure.

The Finite Element and Boundary Element Methods are both well established numerical techniques for analysing a wide range of engineering problems. In the present thesis these numerical techniques are used for obtaining a more realistic picture of various characteristics of concrete gravity dams. The present work addresses the behaviour of gravity dams under static loading, and the developed analysis procedure/computer package can cater for a wide range of dam characteristics including: the three-dimensional behaviour of a gravity dam-foundation-abutments system; the non-linear behaviour of a dam and foundation materials; the sequential construction of a dam and impounding of the reservoir loading on the structure; the effect on stresses of interfaces and joints existing between a dam and its foundation, and in the body of a dam itself; the action of pore water pressure within the foundation, at the dam-foundation interface, and in the body of a gravity dam; etc. Using the purpose written computer package which can cater (in an efficient and accurate way) for the influence of all such factors, mathematical programming methods are, then, used to produce a powerful tool for the shape optimisation of gravity dams leading to safe, functional and economical solutions to the problem. In the course of developing the computer program, much care has been exercised as regards the appropriate selection of the finite element types, mesh configurations and mesh densities, in order to reflect (in an efficient fashion) the variation of stress gradients in the body of a gravity dam. In order to reduce high costs associated with a full three-dimensional analysis, a rather efficient method is developed which enables one to carry out equivalent twodimensional computer runs which will effectively simulate the actual three-dimensional behaviour of gravity dams in, for example, narrow valleys. The proposed approach reduces the dimensionality of an actual problem by one, thus, eliminating the main disadvantage of the finite element method in terms of high solution costs for threedimensional problems. As a result, the proposed method makes the solution procedure highly cost effective. By coupling the finite element-boundary element (FEBE) techniques, which can cater for the material non-linearities in the appropriate regions of the foundation, an attempt is made to by-pass the individual disadvantages of both these numerical techniques. It has, then, been possible to exploit the advantages of reducing the dimensionality of the foundation region by one using the boundary element technique, and, hence, come up with significant savings in terms of computer running times. Anisotropic tangent constitutive models for plain concrete under a general state of biaxial static monotonic loading for, both, plane-stress and plane-strain states of stresses are proposed which are simple in nature, and use data readily available from uniaxial tests. These models have been implemented into the computer program which is, then, used to investigate the influence of the step-by-step construction of the dam and the sequential impoundment of the reservoir loading on the state of stresses. The non-linear program is also used to analyse various characteristics of Bratsk concrete gravity darn (in Russia). The correlations between the numerical results and extensive field measurements on this darn, have been found to be encouraging. Isoparametric quadratic interface finite elements for analysing the darnfoundation interaction problem have also been developed. These elements have zero thickness and are based on an extension of the linear interface elements reported by others. The numerical problems of ill-conditioning (usually associated with zero thickness elements) are critically investigated using test examples, and have been found to be due to inadequate finite element mesh design. Non-linear elastic tangent constitutive models for simulating the shear stress-relative displacement behaviour of interfaces have also been developed, and are used to analyse the effects of including interface elements at the dam-foundation region of contact. It is shown that the inclusion of interface elements in the numerical analyses of the dam-foundation system leads to rather significant changes in the magnitudes of the critical tensile stresses acting at the heel of the dam, which have previously been evaluated (by others) using a rigid dam-foundation interconnection scheme. Effects of pore water pressure, acting as a body force throughout the foundation, the dam-foundation interface and the body of a gravity dam, are also critically studied, with the pore pressure values predicted by seepage analysis. Using an extensive set of numerical studies, a number of previously unresolved issues as regards the influence of pore pressures on the state of stresses are clarified. The effect of drainage on the state of stresses within the body of a dam is investigated, and an insight is also given into the effect of the uplift acting at the lift lines between successive layers of Roller Compacted Concrete (ReC) dams. A shape optimisation procedure for gravity dams based on the penalty function method and a sequential unconstrained minimisation technique is also developed. A number of shape optimisations of idealised gravity dams are carried out in order to compare the numerical results with previously available analytical solutions. The present work also caters for the effects of foundation elasticity and uplift on the optimal shape of a gravity dam. A numerical example is provided covering the shape optimisation of a hollow gravity dam. Finally, the shape optimisation of an actual dam (i.e. Tvishi gravity dam in Georgia) using the presently proposed procedures is carried out with the fmal results compared with those available from the project design team. Wherever possible. numerical outputs have been checked against available small or full scale test data or previously reported closed form solutions. Throughout this thesis very encouraging correlations between the present predictions and such experimental and theoretical data have been obtained.

In the construction sector, capturing the building product in a single information model with good interoperable capabilities has been the subject of much research efforts in at least the last three decades. Contemporary advancements in Information Technology and the efforts from various research initiatives in the AEC industry are showing evidence of progress with the advent of building information modelling (BIM). BIM presents the opportunity of electronically modelling and managing the vast amount of information embedded in a building project, from its conception to end-of-life. Researchers have been looking at extensions to expand its scope. Sustainability is one such modelling extension that is in need of development. This is becoming pertinent for the structural engineer as recent design criteria have put great emphasis on the sustainability credentials in addition to the traditional criteria of structural integrity, constructability and cost. Considering the complexity of nowadays designs, there is a need to provide decision support tools to aid the assessment of sustainability credentials. Such tools would be most beneficial at the conceptual design stage so that sustainability is built into the design solution starting from its inception. This research work therefore investigates how contemporary process and data modelling techniques can be used to map and model sustainability related information to inform the structural engineer’s building design decisions at an early stage. The research reviews current design decisions support systems on sustainability and highlights existing deficiencies. It examines the role of contemporary information modelling techniques in the building design process and employs this to tackle identified gaps. The sustainability of buildings is related to life cycle and is measured using indicator-terms such as life cycle costing, ecological footprint and carbon footprint. This work takes advantage of current modelling techniques to explore how these three indicators can be combined to provide sustainability assessment of alternative design solutions. It identifies the requirements for sustainability appraisal and information modelling to develop a requisite decision-support framework vis-à-vis issues on risk, sensitivity and what-if scenarios for implementation. The implementation employed object-oriented programming and feature modelling techniques to develop a sustainability decision-support prototype. The prototype system was tested in a typical design activity and evaluated to have achieved desired implementation requirements. The research concludes that the utilized current process and data modelling techniques can be employed to model sustainability related information to inform decisions at the early stages of structural design. As demonstrated in this work, design decision support systems can be optimized to include sustainability credentials through the use of object-based process and data modelling techniques. This thesis presents a sustainability appraisal framework, associated implementation algorithms and related object mappings and representations systems that could be used to achieve such decision support optimization.

The UK Government has placed the need to reduce national energy demands and carbon emissions at the forefront of the political agenda, with a commitment made to meet EU targets of 20% reductions in greenhouse gas emissions and primary energy consumption, alongside a 20% improvement in overall energy efficiency, across all EU Member States, by 2020. Building performance has been identified as a key area where significant progress towards meeting these ambitions can be made. It is fundamental to ensure that the building fabric of a property functions correctly in order to achieve high levels of thermal effectiveness, which should result in lower energy demands and carbon emissions. However, research to date shows that a gap exists between predicted and actual performance levels. This research utilises the dwelling Heat Loss Coefficient (HLC) as a common output in design stage and post-construction evaluation techniques, that can be used to compare predicted and measured fabric performance. The Standard Assessment Procedure (SAP), coheating tests, air pressure tests and thermal imaging are used to evaluate in-situ buildings. Sensitivity analysis and controlled conditions experiments are utilised in order to investigate the reliability of the assessment techniques used. The key findings from the study include the demonstration, through novel coheating test, that post-installation mechanically ventilated heat recovery (MVHR) system efficiency levels can have a pronounced effect on the measured HLC, and, in conjunction with use of assumed theoretical efficiency levels, can cause divergence in theoretical and measured data of 10-15%. This can largely be resolved through correct design, installation and commissioning. Environmental conditions, both notional and site-specific, can also cause divergence in the HLC data, including wind speed (15%) and solar gains (10-26%). In addition, it has been shown that, when considering thermal bridging values, inaccurate calculation at the design-stage and poor attention to detail during construction could cause underperformance in this element by up to 50%. This is of significance as there are currently no mandatory procedures to assess post-construction compliance with thermal bridging levels specified within the UK Building Regulations.

Growth in technological advancement was to humanity a mixed blessing. While it provided comfort and improved quality of life, it also increased the demand for energy to drive them. This increase in energy usage, particularly from fossil fuel sources is widely understood to be responsible for the critical environmental problems in the world (Climate Change). Mitigating and adapting to this anthropogenic induced consequence created the need for varying innovative and new low carbon and renewable technologies which are gradually replacing the traditional high fossil fuel driven systems in buildings. Presently in the UK, every new building is expected to be low carbon and energy efficient; operated in such a manner as to use no more fuel and power than is reasonable in the circumstances. However, it is widely believed that construction underperforms in terms of capacity to deliver value. Clients and end-users of these buildings appear not to be getting long term value for their investments. Much attention has also not been given to how these new and innovative technologies can be operated and maintained long into the future. Recent researches also underpin the fact that the wide information gap existing between designers and building end-users is one of the factors responsible for the underperformance. This research therefore sought to explore a best practice approach that could bridge this information gap, and ensure that low carbon buildings are efficiently operated and maintained long into the future, particularly as the UK built environment moves closer to its zero carbon targets of 2016 and 2019. The research methodology involved triangulation (a mixed-method research approach), thus maximising the chances of benefiting from the strength of each of qualitative and quantitative methods. Interviews, surveys and case studies were employed. Post occupancy evaluation method was also used for the key case study. Findings indicate that there is a need for change in the way low carbon buildings are delivered to the end-users; that a properly prepared operation and maintenance (O&M) manual is indispensable in the effective and efficient operation and maintenance of low carbon buildings, and that it will be good practice to bring in the O&M team early to the design process. The study also suggested that designers be required to prove ‘life-cycle operability and maintainability’ of their designs before they are constructed. To ensure this desired cultural and process change in project delivery, a Maintainability and Operability Integrated (OMI) Design and Construction Process Model is proposed. The model was developed using the proposed RIBA 2013 revised Outline Plan of Work and drawing lessons from the New Product Development (NPD) process used by the manufacturing sector and other construction industry models. A validation test was conducted by means of a focus group, populated by top management officials of the University of Nottingham Estates Office, which has been actively involved in the procurement and management of myriads of low carbon buildings. Feedbacks from the validation test indicate that the proposed OMI Process Model was a well thought out idea which is practicable and capable of addressing the shortfall within the existing processes to deal with the O&M issues raised by the use of new and innovative low carbon technologies.

Sandwich panels are a type of structural panel, typically comprising two thin layers of high strength and stiffness known as face sheets which separate a thicker lightweight core of lower strength, stiffness and density. When combined, these layers offer excellent flexural strength to weight ratio without compromising on stiffness. Sandwich panels are utilised in a wide range of industries and applications from aerospace to construction. Due to mismatch of properties between face sheets and core, stress concentrations can occur at the interfaces, often causing delamination. One solution is inclusion of a functionally graded core; a core with properties which vary gradually from the face sheets to the centre, eliminating any abrupt changes in properties. Current research presents newly developed three dimensional analytical and numerical solutions used to gain further understanding of the introduction of a functionally graded core. A three dimensional elasticity solution for an isotropic sandwich panel with stiffness of the core graded in the thickness direction was developed, allowing for comparison of panels with functionally graded and homogenous cores to be completed. It was discovered that inclusion of the graded core removes the discontinuity in stresses at the interfaces and decreases both in- and out-of plane displacements throughout the panel. Since many real functionally graded materials do not exhibit isotropic characteristics, a three dimensional elasticity solution was thereafter developed for a sandwich panel with transversely isotropic core. The effects of individual engineering constants on panel performance were then studied and it was noted that the effects of shear deformation are obvious in thinner panels and those with low transverse shear modulus. A finite element model in ABAQUS was also developed, allowing geometry, loading and boundary conditions to be easily varied. To capture the continuously varying properties of the graded core, user defined graded finite elements were implemented.

No description available.

No description available.

This research thesis was developed as a planning and design reference for mental health treatment centres. This text is intended to assist planners, designers, and health practitioners to optimize patient health and comfort by providing suitable environments to facilitate care and treatment. This thesis examines and provides guidance on security issues, environmental design, the cognitive environment, and site development. Sample facility plans are also provided to demonstrate the design principles advocated. The foreword examines the historical background of mental health treatment facilities in relation to the context of care. The continuing problem of the alienating and dehumanizing effects of psychiatric hospitals on patients is also addressed. Security requirements are investigated in relation to patients' rights and personal needs. This text also examines related fire safety requirements and design measures to minimize the risks of suicides, self injuries, and assaults. Environmental design issues, including lighting, color, acoustics, construction materials, air quality, and spatial relationships, are examined in relation to mental and physical health. Cognitive issues such as wayfinding, mental maps, symbolism, and perceptions of physical environments and architectural design are explored in relation to mental health treatment facilities. Earlier research suggests that patients have difficulty making the cognitive adjustment to typical mental health treatment facilities, and this can negatively effect their therapy and potential recovery. An illustrated questionnaire was developed to help determine the types of facilities patients can relate to and experience relative comfort. This questionnaire was used to examine perceptions of buildings and designs in relation to the provision of comfortable and healthy environments. The survey revealed that patients, health care providers, and students shared similar perceptions of the built environment, and that buildings possessing features generally associated with domestic buildings (houses) were considered more comfortable than other building types. In particular, buildings with pitched roofs and brick exteriors were considered most suggestive of comfort. Horizontal windows were preferred to more common vertically oriented windows. This effect was more pronounced when windows framed a pleasant natural view. Curved interior forms were also found to be suggestive of comfort. Past, current, and emerging patterns of site and facility development are reviewed in association with their environmental context. The role of nature in the healing process, from ancient Greece to recent discoveries, is also examined. The final chapter of this thesis is a demonstration of design principles with annotated drawings of a hypothetical inpatient unit and outpatient clinic. These drawings are provided to demonstrate an integration of thesis findings and design principles. These drawings are not a definitive design or prototype, because every site and building program are different and require their own design solution.