This research was undertaken to investigate the effectiveness of carboxylic corrosion inhibitor in fly ash and silica fume (respectively FM and SM) samples and nitrite-based corrosion inhibitors in fly ash (FGC) sample. The findings from this research show that the addition of the carboxylic inhibitor altered the hydration of fly ash and silica fume self-compaction concretes (SCCs) by delaying the formation of ettrngite and the production of portlandite in the FM and SM samples and ultimately causing the calcium aluminate hydrates to surround the fly ash and cement particles. It was shown that this resulted in slight setting retardation in the silica fume particles but significant delay in the hydration of the fly ash SCC. Further, this development brought about by the use of the carboxylic inhibitor contributed bleeding of different levels in the fly ash and silica fume samples and this condition was shown to increase the heterogeneity of the FM and SM SCCs. Although addition of the nitrite-based inhibitor retarded the setting of paste of the fly ash SCC, no noticeable delay in the hardening of the concrete was manifested. When the nitrite-based inhibitor was included in the fly ash SCC, the physical structure of the interfacial transition zone and the bulk of the mortar were found to be less porous and hence the concrete displayed a higher level of homogeneity. The incorporation of the carboxylic inhibitor increased the corrosion resistance of the silica fume concrete to chloride -induced corrosion but the corrosion resistance of the fly ash SCC was only improved when exposed to low concentration of chloride ions. The reduction in the inhibiting capacity of the FM SCC to high chloride load was the result of the elevated degree of porosity and higher propensity to chloride migration resulting from the use of the carboxylic compound. On the other hand, when the nitrite compound was used in the fly ash SCC, the current density was reduced which is ascribed to the effectiveness of the inhibitor and the reduction in the porosity and chloride migration that resulted from the incorporation of the inorganic compound. However, as the concentration of the corrosion inhibitors increased, the corrosion resistance of the inhibited SSCs reduced. The study also shows that the nitrite fly ash see showed the ability to undergo self-healing of corroded reinforced concrete but the carboxylic inhibited types of SCCs (FM and SM) could only prevent further corrosion after the corrosive environment is removed. Comparative testing showed that, in all three types of inhibited SCCs, there is a high probability that the inhibiting capacity will become depleted under certain conditions of chloride exposure. Using the nitrite inhibitor in the fly ash SCC also imparted moderate to significant improvement to the 7 - 60-day compressive strengths but the long term strength of the concrete was slightly lower than that of the traditional fly ash SCC. When the carboxylic compound was used in the fly ash SCC, the 7 - 28-day compressive strengths were marginally lowered and the 60 - 90-day compressive strengths were profoundly reduced. The addition of the carboxylic inhibitor to the silica fume SCC also significantly reduced the 28 - 90-day compressive strengths of the concrete.

This thesis reports on the microstructure of Al-Sn based powders and the development of Al-Sn based coatings for automotive shell bearing applications deposited using the high velocity oxy-liquid fuel (HVOLF) thermal spray technique. The microstructure of the coating and its associated physical and chemical properties, such as microhardness and corrosion resistance, are investigated as a function of the HVOLF thermal spraying parameters. In particular, a detailed microstructural understanding of the thermal sprayed coatings is developed to explain the coating properties. Two alloy systems, Al-12wt. %Sn-1 wt. %Cu and Al-20wt. %Sn-3wt. %Si have been investigated in detail using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analysis. The high resolution transmission electron microscope (HRTEM), electron energy loss spectroscopy (EELS) and energy filtered TEM have also been used to examine nanoscale precipitates as supplementary methods. The statistical image analysis of fine scale particulate dispersions has also been used to study the second phase evolution with annealing. The microstructure of the large gas atomised powder particles used in the HVOLF thermal spray process comprise dendritic Al and interdendritic Sn, whilst the small powder particles exhibit fine scale Sn particles distributed within an Al matrix. The as-sprayed coatings comprise a mixture of melted and partially melted splats due to the full and partial melting of the deposited powder. Nanoscale Sn particles distributed in the Al matrix are present in fully melted regions, whilst micron / sub-micron Sn particle distributions and Sn-particle free Al regions delineate partially melted regions. Cu remains in solid solution within the Al matrix of the Al-12wt. %Sn-1 wt. %Cu as-sprayed coatings, whilst Si formed nanoscale particles in the Al-20wt.%Sn-3wt.%Si as-sprayed coatings. The critical cooling rate to form the metastable liquid phase separationh within Al-12wt%Sn alloys is put forward according to calculation. If the cooling rate is lower than the critical cooling rate, dendritic Al and interdendritic Sn are formed, thereby explaining the structure of large gas atomised powder particles. If the cooling rate is higher than the critical cooling rate, a liquid phase separation reaction occurs to form fine scale Sn dispersion. The calculated critical Al-12wt.%Sn powder diameter for liquid phase separation is close to the experimentally observed Al-12wt. %Sn-l wt. %Cu powder diameter. The discrepancy between experiment result and theoretical calculation is attributed to the additional element Cu promoting the liquid phase separation. The nano and sub-micron scale Sn distribution in small gas atomised powder particles and the as-sprayed coatings is attributed to the cooling rate being higher than the critical cooling rate. The dendritic structure of the large Al-Sn-Cu gas atomised powder is due to the cooling rate being lower than the critical value. Heat treatments are applied to the as-sprayed coatings to alter the mechanical and chemical properties, such as, microhardness and corrosion resistance, of the bearing material coatings. Annealing causes the nanoscale and sub-micron Sn particles to coarsen within both Al-12wt.%Sn-1 wt.%Cu and Al-20wt.%Sn-wt.3%Si coatings according to the analysis of SEM and TEM images. The Sn particles coarsen greatly within the Al-12wt.%Sn-1wt.%Cu coatings annealed at 300°C for 5 hours, as compared with coatings annealed for 1 hour. The Ɵ’-phase (CuAl2) also precipitates in the Al-12wt.%Sn- 1 wt.%Cu coatings after annealing at 300°C. Annealing also causes fine scale Si particles to coarsen greatly in the Si containing alloy. The microhardness decreases in the annealed coatings for both alloys and is attributed to a coarsening of Sn particles and the release of residual strain within the as-sprayed coatings. As compared with the as-sprayed coatings and the coatings annealed at 300°C for 1 hour, the corrosion rate in 0.1M NaCI solution of Al-12wt.%Sn-1wt.%Cu coatings annealed at 450°C for 1 hour is very greatly reduced. However, an annealing temperature of ~450°C is not appropriate for these coatings because of the introduction of interlayer cracks and a coating / substrate reaction which might degrade the mechanical properties of the bearing.

Micro-Electro-Mechanical Systems (MEMS) inertial sensors that are based on a resonating structure are used in a wide range of applications including inertial guidance and automotive safety systems. Damping has a significant and negative effect on sensor performance and there is an increasing need to accurately predict and control damping levels, particularly for high performance guidance and navigation applications. Support loss, which governs the losses from the resonator to its foundation through the supporting structure, is an important source of damping in MEMS resonators. This thesis focuses on improving the understanding of this particular damping mechanism and on developing efficient models to predict support loss at the design stage. The coupling between resonator and support is of primary interest when evaluating the interaction and energy transmission between them. To quantify the stresses acting on the support, a model that predicts vibration transmission through common MEMS structures is first developed. A general wave propagation approach for the vibration analysis of networks consisting of slender, straight and curved beam elements, and a complete ring is presented. The analysis is based on a ray tracing method and a procedure to predict the natural frequencies and mode shapes of complex ring/beam structures is demonstrated, for both in-plane and out-of-plane vibration. Furthermore, a simplification of the analysis for cyclically symmetric structure is presented. An analytical method is then used to model the support, approximated as a semi-infinite domain, and to quantify support losses, again for both in-plane and out-of-plane vibration. To illustrate the effectiveness of the models, several numerical examples are presented, ranging from simple beam-like structures to ring/beam structures of increasing complexity. A parametric study on the design of particular ring-based resonators, and general strategies for improving the quality factor of common MEMS sensors by reducing support losses, are also considered.

In the context of fossil-fuel shortage and climate change, the production, conversion, storage and distribution of energy have become the focus of today's world. Supercapacitors, with their unique energy and power density specifications, cover the application gap between batteries and conventional capacitors and hence making valuable contributions in energy storage and distribution. Caron nanotubes (CNTs), with their unique aspect ratio and other distinctive physical, electrochemical and electronic properties have been chosen to enhance traditional electrode materials for supercapacitors, i.e. conducting polymer and transition metal oxides. Polypyrrole/CNTs (PPy/CNTs), polyaniline/CNTs (PAni/CNTS) and manganese oxides/CNTs (MnOx/CNTs) nanocomposites have been synthesised through chemical redox reaction in aqueous solutions. The nanocomposites have been characterised with scanning electron microscopy (SEM), transition electron microscopy (TEM), BET nitrogen surface adsorption, X-Ray diffraction (XRD), thermogravimetric analysis (TGA), infrared and X-ray photoelectron spectroscopy (XPS) to examine and to select the appropriate candidates as electrode materials. Electrochemical characterisations, i.e. cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), have been conducted with the selected nano-composites in a classic three-electrode compartment cell. Desirable capacitive behaviour, with long-term cycling stability, has been identified within appropriate potential windows for each of the nanocomposites. Asymmetric and symmetric supercapacitor prototypes have been constructed with the nanocomposites synthesised and characterised in this work. Carbon materials, due to their higher hydrogen overpotential in aqueous systems, have been proved to be good negative electrode materials in this study. Excellent specific capacitances of 1.2 F cm-2, 0.83 F cm-2 and 0.96 F cm-2 have been achieved with PAni/CNTs, PPy/CNTS and MnOx/CNTs electrodes respectively. Supercapacitor-stacks with multiplied cell voltage have been constructed with both symmetric and asymmetric prototype cells. Therefore, it has been confirmed that desirable cell voltage and capacitance can be achieved by connecting appropriate individual cells in parallel and in series to cater the requirements of the end-users. Last but not least, the prototype cells have been fitted with equivalent circuits to gain an insight into the resistive and capacitive contributions from each component. Suggestion for improvement has been given based on the simulation results of the prototype cells.

This research is concerned with quantifying damage in asphalt mixtures at the micro level. X ray Computer Tomography (CT) a non destructive technique along with image analysis has been used to study the internal microstructural properties of asphalt. During laboratory testing of asphalt mixtures, it has been observed that specimens lose strength without any visible cracks. UK asphalt mixtures have been tested in uniaxial compression and tension compression fatigue tests and scanned in X ray CT. In the uniaxial compression test, specimens have been tested at three different strain rates. Both monotonic and cyclic tests have been conducted at three different temperatures. Testing has been carried out both continuously and with rest periods at selected stages. The specimens were scanned in X ray before starting the tests and also during the testing at on selected stages until failure. X ray machine operation was optimized to achieve good quality of images of different types of asphalt samples. The 2D images of the specimens were collected from the X ray CT and were stacked to regenerate into 3D images of the asphalt samples. Techniques for adjusting the threshold grey values of the images and analysing the X ray images for different parameters have been developed. The images have been analysed to evaluate the microstructure of the asphalt specimens internally and non destructively. Air voids content is considered as the parameter that represents the change in microdamage during the application of loading cycles. Moisture damage in asphalt mixtures was studied from X ray CT. Two types of mixture were investigated, one with acid aggregate and one with basic aggregate, with three different ranges of void content. Dry specimens and specimens saturated in the laboratory were scanned in X ray CT to study the internal connected air voids which cause the permeability to moisture in an asphalt mixture and result in moisture damage. Damage due to combined moisture and ageing was studied from X ray images. From the analysis of X ray images, it was observed that a non uniform increase in air voids occurred both along the height and across the diameter of the specimens tested in monotonic compression and tension compression fatigue. This may perhaps be due to the heterogeneous nature of asphalt. New voids developed along with a size increase and joining together of existing voids. Using continuum damage mechanics, the data from both the mechanical testing and from X ray computer tomography was compared. For specimens tested in fatigue, damage parameters were determined for a damage model. The dissipated pseudo strain energy approach was applied to the test data and the parameters for the damage model were determined. A modified model with a new parameter of adhesion between binder and aggregate was used for data analysis. Results from X ray computer tomography and from the fatigue damage model were compared. In the case of specimens tested for moisture damage and ageing, the retained saturation was determined from X ray image analysis and was related to the stiffness of asphalt mixtures. Asphalt mixtures containing basic aggregate were found to have a high retained stiffness value after moisture and ageing tests compare to mixtures containing acidic aggregate. The stiffness values for the retained saturation were determined and it is observed that in the case of mixtures containing acidic aggregate, the retained stiffness decrease with the increase in retained saturation.

Three-dimensional data are useful for various applications such as visualization for planning, simulation for training and environmental studies, presentations, decision making and many more. The existing methods of texturing 3-D city models use conventional vertical imagery and libraries of generic textures which are sufficient for some applications of 3-D models like training simulation, gaming, and telecommunication planning. However, the needs for photo-realistic, modelling of the complete details, and geometrically accurate 3-D models are growing rapidly in several fields, especially in engineering and cultural heritage documentation. Photorealism and better details can be achieved through using terrestrial imagery but it is a very time-consuming process particularly in large modelling projects. It is possible to improve efficiency by image capture from a moving ground based vehicle but this requires an extra process in the work flow if the initial modelling has been undertaken by aerial photogrammetric processes. Pictometry imagery has been used for visual inspection especially in life-saving situations due to the fact that the Pictometry aerial imagery contains oblique (angled) images which provide better view and greater detail. The more conventional method of collecting aerial images with for example the UltraCamD, can also provide excellent views of roof tops and some of the building facades when located away from the nadir on the images. This research explored the geometry of the Pictometry images (vertical and oblique) and the possibility of using this imagery in 3-D modelling to produce photo-realistic and accurate models. In addition, merging terrestrial imagery with Pictometry imagery to get more ground level details has been investigated in this research. All work has been carried out using the available software packages at the Institute of Engineering Surveying and Space Geodesy (IESSG) and using data provided by Blom Aerofilms Ltd. The results of the aerial triangulation of different Pictometry blocks showed that high quality image measurements have been achieved for all the image blocks. The use of indirect georeferencing produced good quality coordination of ground points. The use of in-flight control has produced good results with additional parameters which mitigate any effects of systematic errors. Good quality AT results have been achieved using minimum ground control which reduces a lot of field work and hence time and money. Extraction of 3D geometry for all buildings in the study area has been performed using both vertical Pictometry imagery and UltraCamD imagery. The polygons extracted from the UltraCamD images have been used as a bench mark (BM) to check the accuracy of polygons extracted from Pictometry. Planimetric and height comparisons of the extracted features from Pictometry system with the BM results have been performed. The results showed that the Pictometry imagery produced good results especially in plan components taking into consideration the differences in the resolution, GSD, and the flying height between the two camera systems. The results of automatically texturing the models have shown that using the vertical blocks (UltraCamD or Pictometry) produced very good roof textures but on the other hand produced less quality facades. The use of the Pictometry oblique block in texturing has produced very good facades but in some instances not such good quality roof textures. The successful combining of vertical and oblique Pictometry images provided an excellent opportunity to produce an efficient method of high quality urban model texturing. The integration of terrestrial images of building facades (whose texture needs enhancement) with the combined aerial imagery block has been successfully and automatically performed. The results are much better than the results obtained by manual texturing which not only depends upon the experience and skill of the operator but is also time consuming and laborious

This thesis is mostly about the analysis of second order linear vibrating systems. The main purpose of this study is to extend methods which have previously been developed for either undamped or proportionally damped or classically damped systems to the general case. These methods are commonly used in aerospace industries. Ground vibration testing of aircraft is performed to identify the dynamic behaviour of the structure. New aircraft materials and joining methods - composite materials and/or novel adhesive bonding approaches in place of riveted or welded joints - cause higher levels of damping that have not been seen before in aircraft structure. Any change occurring in an original structure causes associated changes of the dynamic behaviour of the structure. Analytical finite element analyses and experimental modal testing have become essential tools for engineers. These techniques are used to determine the dynamic characteristics of mechanical structures. In Chapters 3 and 4, structural analysis and modal testing have been carried out an aircraft-like structure. Modal analysis techniques are used to extract modal data which are identified from a single column of the frequency response matrix. The proposed method is presented for fitting modal peaks one by one. This technique overcomes the difficulty due to the conventional methods which require a series of measured FRFs at different points of excitation. New methods presented in this thesis are developed and implemented initially for undamped systems in all cases. These ideas are subsequently extended for generally damped linear systems. The equations of motion of second order damped systems are represented in state space. These methods have been developed based on Lancaster Augmented Matrices (LAMs) and diagonalising structure preserving equivalences (DSPEs). In Chapter 5, new methods are developed for computing the derivatives of the non-zeros of the diagonalised system and the derivatives of the diagonalising SPEs with respect to modifications in the system matrices. These methods have provided a new approach to the evaluation and the understanding of eigenvalue and eigenvector derivatives. This approach resolves the quandary where eigenvalue and eigenvector derivatives become undefined when a pair of complex eigenvalues turns into a pair of real eigenvalues or vice-versa. They also have resolved when any one or more of the system matrices is singular. Numerical examples have illustrated the new methods and they have shown that the method results overcome certain difficulties of conventional methods. In Chapter 6, Möbius transformations are used to address a problem where the mass matrix is singular. Two new transformations are investigated called system spectral transformation SSTNQ and diagonalising spectral/similarity transformation DSTOQ. The transformation SSTNQ maps between matrices of two systems having the same short eigenvectors and their diagonalised system matrices. The transformation DSTOQ maps between two diagonalising SPE‟s having identical eigenvalues. Modal correlation methods are implemented to evaluate and quantify the differences between the output results from these techniques. Different cross orthogonality measures represent a class of methods which are recently performed as modal correlation for damped systems. In Chapter 7, cross orthogonality measures and mutual orthogonality measures are developed for undamped systems. These measures are defined in terms of real matrices - the diagonalising structure preserving equivalences (DSPEs). New methods are well developed for ill-conditioned system such that they work for all occasions and not only for cases where mass matrix is non-singular. Also a measure of the residuals is introduced which does not demand invertibility of diagonalised system matrices. Model updating methods are used in order to update models of systems by matching the output results from analytical system models with the experimentally obtained values. In Chapter 8, both cross-orthogonality measures and mutual-orthogonality measures are developed and used in the model updating of generally damped linear systems. Model updating based on the mutual orthogonality measures exhibits monotonic convergence from every starting position. That is to say, the ball of convergence has an infinite radius whereas updating procedures based on comparing eigenvectors exhibit a finite ball of convergence. Craig Bampton transformations are one of component methods which are used to reduce and decouple large structure systems. In Chapter 9 Craig Bampton transformations are developed for undamped systems and extended for damped second order systems in state space. Craig Bampton transformations are generalised and presented in SPEs forms. The two parts of the Craig Bampton transformations are extended in the full sizes of the substructure. The extended Craig Bampton transformations are modified to format each block of transformed substructure matrices as LAMs matrices format. This thesis generalises and develops the methods mentioned above and illustrates these concepts with an experimental modal test and some examples. The thesis also contains brief information about basic vibration properties of general linear structures and literature review relevant to this project.

This thesis is primarily aimed at carrying out analysis of Energy Bags, reinforced fabric bags used for subsea compressed air energy storage. Subsea compressed air energy storage is a completely new method of large-scale energy storage designed to be integrated with direct-compression offshore wind turbines and wave energy converters. Energy Bags are impermeable bags anchored to the seabed at significant depths (e.g. 500m) in which high pressure air, compressed by specially designed wind turbines and wave energy converters, is stored at pressures roughly equal to the hydrostatic pressure of the surrounding water. Energy Bags do not need to be particularly strong because most of the reaction to the pressure load is provided by the surrounding water, and high energy densities are available at such depths as 500m. This thesis investigates the deformed shapes of Energy Bags and studies optimal designs. Three analysis methods are developed which vary in their complexity, ease of use, and accuracy. First, a system of coupled ordinary differential equations (ODEs) is derived which describes the deformed shape of an axisymmetric Energy Bag. This model is later used in an optimisation study to find the shapes of bag which minimise the cost of materials (reinforcement, fabric, and ballast) per unit of energy stored. Circumferential reinforcement, hanging masses from the inside of the bag (which it was hoped would lower the total cost) and fill level are all included as variables in the optimisation, and it is found that for reasonable materials costs an Energy Bag could cost less than £10,000/MWh when anchored at 500m. This compares favourably with all other methods of large-scale energy storage. However, the bags used in the optimisation study have wide bases, which will require sealing against the seabed (unless water is to be allowed into the bags). Problems are encountered when trying to use the ODE method to find the shapes of partially inflated bags, and it is generally not very easy to use. Next, we carry out finite element analysis (FEA) of an axisymmetric Energy Bag using cable elements. This is much more user-friendly and flexible than the ODE method. Partially inflated bag shapes are found, and pressure-volume curves are presented which show the almost isobaric performance of an Energy Bag. It is found that material mass limits the extent to which the bag can be deflated before it becomes unstable. The axisymmetric FEA is used to study bags with much more realistic circumferential reinforcement than the ODE method, and we also look at bags with an unsealed base, which allow water in through the base as they deflate. A three-dimensional FEA tool is presented which models an Energy Bag as a cable-reinforced membrane using cable and membrane elements, and special measures had to be taken to deal with wrinkling. We assume that the bag is rotationally symmetric, comprising a number of symmetric lobes. The 3D FEA is used to find the stress distribution in the membrane of the bag, however a converged solution cannot always be found. It is not certain why this is the case but it is anticipated that it is because deformed bags are not always rotationally symmetric. The 3D FEA could also be used to model other membrane structures such as balloons, parachutes, roofs and sails, as well as nets. The standard cutting patterns for lobes in lobed balloons are analysed, and a new cutting pattern known as the Constant Tension lobe is generated. This is an extension of the Constant Radius lobe and takes into account the pressure gradient found in both air and water, minimising waste material. The Constant Tension lobe is particularly appropriate for Energy Bags because of the large pressure gradient in water. The Ultra High Performance Vessel architecture is also presented, upon which the design of the prototype Energy Bags is based. The fabric structure of an Ultra High Performance Vessel comprises only two sheets of fabric (rather than many separate lobes welded together), and tendon shortening and “bellows” serve to ensure that there is no meridional stress in the fabric. An analytical optimisation is used to show that the zero pressure bag that minimises cost of materials per unit of energy stored has equal costs of reinforcement and membrane. The axisymmetric FEA is also used to find the optimum bag size and maximum fill level for a bag which comes down to a single point at the base (as opposed to a wide base bag). Finally, testing of two 1.8m diameter superpressure Energy Bags has been commenced during the course of this work, and the prototypes and test rig are documented in this thesis. The prototypes were manufactured for us by Thin Red Line Aerospace Ltd., a Canadian manufacturer of deployable fabric structures for use in space. They are being cycled back-to-back in order to prove the concept, assess the performance of an Energy Bag over time, and identify any problems that need to be addressed. One of the bags had a few small leaks from the moment it was first inflated, but the other has remained airtight to date. It was found that if an Energy Bag is to be airtight, special attention must be paid to the welds at the seams and the sealing around the airline fittings.

The use of hollow section columns in steel construction is presently hindered by the lack of adequate connection technologies. Due to access constraints, standard bolting techniques are difficult to achieve, if not impossible without welding. As an alternative to welding, blind-bolting techniques were developed to provide desirable bolted configurations, allowing hollow column frames to be erected in the same way as open profile column frames. But the current blind-bolting techniques are restricted to the construction of simple connections because of their difficulties in achieving sufficient tensile stiffness. More recently, a novel anchored blind-bolt, labelled the Extended Hollo-bolt (EHB), has been developed at the University of Nottingham; as a modification of the standard Hollo-bolt. For the proposed connection technology, its potential in providing moment-resistance has been assessed successfully. However, the existing data related to the performance of this novel connector in tension is insufficient to permit its design. This work investigates the performance of the EHB blind-bolt under tension loading and focuses on determining, and modelling the stiffness of this novel technology in such a way to enable its application within the component method approach. An extensive experimental programme was devised to collect sufficient component characteristic data to enable the development of an EHB component model. This covered data deals with the overall response of the connector and the individual responses of its contributing elements. A total of 51 experimental pull-out tests and 20 pre-load tests have been performed. The force-displacement behaviour of the investigated joint component was determined under monotonic pull-out testing, where remote video gauge techniques have been adopted to capture the full non-linear response of the component, alongside traditional techniques to confirm the reliability of the data. The test matrix varies the grade and size of the component's internal bolt, the strength of concrete, and the depth of its mechanical anchorage. From the pull-out tests it was identified that the EHB component can ultimately develop the full tensile capacity of its internal bolt. This ultimate failure mode is confirmed for the range of parameters that was covered in this study. Increasing concrete strength had the most enhancing effect on the response of the component. A secondary programme was related to the measurement of pre-load that is induced in the internal bolt of the EHB component at its tightening stage; where pre-load was monitored over a five day period. The test matrix varies the grade and size of its internal bolt, and also considers various bolt batches. It was concluded that the relative level of component pre-load to ultimate strength increased only in the case where higher bolt grades were used. To model the tension behaviour of the EHB component, a mechanical model was developed that is based on an assembly of the component's different sources of deformation. The component model employs idealised springs with tetra-linear characteristics for the elongation of Its Internal bolt element, and springs with tri-linear characteristics for the slip of its expanding sleeves and mechanical anchorage elements. By comparing the predictions of the component model with relevant experimental data, the component model has been shown to be capable of describing the EHB component response with reasonable accuracy; capturing its tensile stiffness and its yielding trend. The accuracy of the component model has also been assessed in exclusion of pre-load effects. It was found that if the level of pre-load Is excluded from the assembly process, this can have highly undesirable effects on the predictions of the component's response. The findings of the supplementary pre-load testing programme assisted greatly in the accuracy of the component model by providing the necessary levels of pre-load. The proposed component model has demonstrated that the behaviour of the EHB component can be modelled by the component method approach; by employing Idealised models for the behaviour of its contributing elements. The validated component model is considered to simulate the tension behaviour of the novel anchored blind-bolt with sufficient fidelity that it can be considered as a benchmark for further studies.

Assessing the damage level of in-service components and obtaining material properties for welded structures exposed to creep is essential for the safe operating of power generation industry. Standard creep testing techniques require relatively large volumes of material for the machining of testing samples. For that reason they are not usually suitable for obtaining creep properties of in-service structures. It has been found that significant amount of the failures in welds exposed to elevated temperatures occur in an area formed due to the complex thermal and cooling cycles during the welding process. Because of this a different approach is needed for the derivation of creep properties from small amounts of metal. The small punch creep testing method is considered to be a, potentially, powerful technique for obtaining creep and creep rupture properties of in-service welded components. However, relating small punch creep test data to the corresponding uniaxial creep data has not proved to be simple and a straightforward approach is required. The small punch creep testing method is highly complex and involves interactions between a number of non-linear processes. The deformed shapes that are produced from such tests are related to the punch and specimen dimensions and to the elastic, plastic, and creep behaviour of the test material, under contact and large deformation conditions, at elevated temperature. Owing to its complex nature, it is difficult to interpret small punch creep test data in relation to the corresponding uniaxial creep behaviour of the material. One of the aims of this research is to identify the important characteristics of the creep deformation results from 'localized' deformations and from the 'overall' deformation of the specimen. For this purpose, the results of approximate analytical methods, experimental tests and detailed finite element analyses, of small punch tests, have been obtained. It is shown that the regions of the uniaxial creep test curves dominated by primary, secondary and tertiary creep are not those that are immediately apparent from the displacement versus time records produced during a small punch test. On the basis of the interpretation of the finite element results presented, a method based on the reference stress approach is proposed for interpreting the result of small punch experimental test data and relating it to the corresponding uniaxial creep data. Another aim of this study is to investigate the effect of friction between the sample and the punch as well as the effects of the basic dimensions, on the small punch creep testing data.