The topic of this thesis is the testing and design of conventionally formed and additive manufactured stainless steel hollow structural sections. Although design codes currently exist for stainless steel hollow structural elements, the provisions are based on limited structural data and therefore require further evaluation for their suitability, and are not intended to apply to additive manufactured elements. Focussing on conventionally formed circular hollow sections (CHS), the existing design provisions have been carefully reappraised based on a dataset of tests and finite element results generated in this study and existing tests collected from the literature. In total, 37 concentrically loaded column tests, 26 beam-column tests and 10 stub column tests have been undertaken on austenitic, duplex and ferritic stainless steel CHS. The experimental data has been supplemented with over 2400 finite element case studies. The reappraisal highlighted that there is additional capacity to be sought at the cross-section level for pure compression, bending and combined loading, and at the member level for beam-columns, but the current CHS flexural buckling provisions were found to be unconservative for certain global slenderness values. Based on these observations, revised design rules have been proposed. Additive manufactured sections, not currently covered by structural design standards, have also been investigated. An experimental programme consisting of 28 tensile coupon tests, 14 compressive coupon tests and 5 square hollow section (SHS) stub column tests has been undertaken. The initial results indicate general applicability of existing design standards to these new novel sections.

Other investigations have shown the relationship between various plate efficiencies and the relationship between the Murphree plate efficiency and the point efficiency for steady-state conditions. So far there has been no work done on the relationship between the Murphree plate efficiency and the point efficiency for unsteady-state conditions. In unsteady-state distillation simulation, the Murphree plate efficiency has been held constant and it is thought that this may be the reason for the differences between experimental and theoretical liquid composition responses in some cases. Further, the liquid mixing models used to represent the mixing occurring on a distillation plate, do not include down-comer sections and the need for experimental investigation of the down-comer effect is required to produce a realistic model. Experimental conductivity impulse responses, using potassium chloride tracer, are obtained on a 7 ft. x 1.5 ft. sieve plate using the system air-water. The sieve trays, weir height and down-comer segmental area are variable, and the responses are compared with those obtained by the diffusion model.

Hemp-lime is a comparatively novel renewable insulation material in the construction industry. Its use was first documented in the 1980’s, however, recent increased interest and the release of popular publications has resulted in an increased need for scientific investigation into the material. The research conducted in this investigation firstly focussed on furthering the empirical characterisation of hemp-lime and its constituents with particular attention paid to minimising fabrication variables and increasing the accuracy of final specimen bulk densities. Secondly attempts were made to quantify the degree of carbon sequestration that occurs as a result of the carbonation of the lime binder. A total of 196 specimens were fabricated for the main programme of work. It has been demonstrated that the novel fabrication methodology developed and tested in this investigation allows for reliable and consistent fabrication of specimens with almost identical final bulk densities. An average intrinsic empirical variability of 0.8% was determined for hemp-lime composites. It has been shown that the values of CO2 sequestration varied between 151- 192kg/m3 for the current formulated binders and composite bulk densities being used or considered in the UK construction industry. This resulted in a minimum 100% increase above the lowest estimated sequestration value from previous investigations. Preliminary carbonation constant values for hemp-lime have been determined, however, further testing is required to establish definite values based on a wider sample of testing.

Masonry structures are especially vulnerable to earthquakes. Previous studies have focused mostly on their mechanical characteristics, while masonry structures vary greatly in terms of structural and material properties. This thesis aims to present the post-crack dynamic behaviour of masonry structures on mechanism. Systematic studies, including pseudo-static experiments, shaking-table experiments and mathematical modelling, were carried out. In the pseudo-static experiments, scaled masonry walls with different geometric forms, bond types and corner connections were tested. The static-phase in-plane and out-of-plane damage mechanisms of masonry walls were classified. Their load factors and the influence of structural configurations were discussed. Experimental load factors are compared with theoretical ones derived from a limit-analysis procedure. The shaking-table experiments successfully captured the dynamic-phase response mechanisms. Three 3D dry masonry models were tested according to sinusoidal excitation based on either constant amplitudes or constant peak accelerations. Conclusions on the dynamic behaviour of the masonry structure were presented. The experimental basis for the theoretical model was presented. The influence of structural configuration and excitation figure were clarified. The critical factors were clarified as being the excitation frequency and L/H ratio of the façade. The consistent damage behaviour variations arising from these two factors were analyzed. A nonlinear dynamic mathematical model for the rocking of the masonry façade was developed, using a two-rigid-body model. The loads and frictional force on the top were included, with a horizontal excitation being applied. Assumptions of rigid ground, inelastic impact and point contact were applied. Six possible patterns were defined. The rocking, the impact and the possible transitions were formulated. Models in the shaking-table experiments were simulated to evaluate this model. Parametric studies were performed and future works were recommended.

The Antarctic built environment is characterised for its particular occupational regimen and includes whole-year stations, small-scale seasonal station and refuges,and temporary field camps. In recent years,Antarctic construction has begun to be considered of interest for the architectural and engineering communities, and interesting efforts have been made to provide solutions for spanning building, energy efficiency and improvements in indoor habitability. A fascinating array of lightweight constructions can be identified, whose contribution has not, until now, been fully documented and acknowledged. They represent remarkable examples of smart use of structural efficiency and minimal impact strategies enduring one of the harshest environments. This research is design-led and is motivated by the extension of the use of lightweight structures in remote fragile areas. The research validates the concept of polar lightweight design through a sound narrative describing the history and potential of this type of construction. For this, this research looks at the case of the Antarctic built environment. Furthermore, this research proposes that extension in the use lightweight construction could offer a sustainable solution for the predicted increase in the number of settlements being established in Antarctica. Knowledge and solutions achieved in this context can also be applied in other less demanding and fragile scenarios. In this regard, advanced computational design tools have been extensively validated for the realisation of structural surfaces of high geometrical complexity. Parametric design tools, are of particular interest to this research, as they allow the optimisation of a structure, either as a whole, or via its physical components. This research proposes that such tools can be employed for the development of Polar lightweight systems of larger scale and more complex configurations than currently seen. The first part is dedicated to the documentation and systematic characterisation of the vernacular Subantarctic and Antarctic lightweight constructions as structural systems. In the second part, the integration of polar constraints in the design of a generic lightweight structural system using parametric design tools is developed, in order to demonstrate the potential of this field for the creation of novel design methods and solutions. The particular case of a new medium-scale seasonal station is used as a case-study.

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The Double Skin Composite (DSC) or Steel-Concrete-Steel (SCS) elements (beams, slabs and columns) have been subjected to intensive studies during the last three decades. Member beam, column and slab have been studied under monotonic, cyclic and fatigue loading, and there are also a few studies on impact loading to assess the structural response of such constructions. Validating connectivity between the DSC beam and DSC columns is behind the usage of such constructional systems since all the present studies focus on individual members. The main objective of this thesis was to introduce the Double Skin Composite (DSC) beam-column joint as a new structural element. Experimental investigation and Nonlinear Finite Element Modelling (FEM) of the structural behaviour of the DSC joint subjected to monotonic and quasi-static loading was introduced. Five DSC joints have been tested to assess the efficiency of the DSC beam-column joint in its basic design and to identify the most efficient strengthening method. Further, six DSC beam-column joints were tested to study the effect of steel fibre (SF) and the effect of high-strength concrete (HSC) on the behaviour of the joint under monotonic loading and under cyclic loading. The general FE Package ABAQUS 6.10 was used to model the nonlinear behaviour of the DSC joint. The Concrete Damage Plasticity Model (CDPM) was used to model the concrete in tension and compression, and the steel elements of the composite were modelled using the elastic-plastic model. The model was validated against the experimental result and showed good agreement in predicting the maximum load and the general behaviour with a deviation of 10% or less. The examined strengthening methods showed improvement in the ultimate load capacity of between 517% and 871%. SFC and HSC provided the best performance in increasing the ultimate load and moving the location of the plastic hinge away from the face of the column. The validated FE model was used to conduct a parametric study to investigate the effect of the concrete compressive strength, shear stud connector spacing to steel plate thickness ratio, and the stud diameter to steel plate thickness ratio. The parametric study findings were in good agreement with experimental observations such as that the concrete compressive strength had a significant effect on the joint shear resistance and ultimate load.

Terrestrial laser scanning has become a popular way of digitising buildings and complex environments. Laser scanning was adopted as the means of capturing 3D data in many elds, including architecture, engineering and environmental survey. It was only a matter of time for the Heritage sector to start using the technology. This thesis describes the scienti c contributions from the collaboration project that explored the viability of automating the laser data acquisition process. The project concentrated on the reduction of the skill set required by the operator of the laser scanner as well as the improvement of the usability of large datasets. The contributions involved the development of a new data representation method, a new visibility estimation metric and an improved volumetric decimation algorithm.

An extensive survey of the deformation problems in the field of rock mechanics is presented. The deformation of most rocks is non-linear and has an irreversible component. This non-linearity and irreversibility may arise from a macro-fissure system in what is inherently a linear elastic rock or it may be intrinsic to a porous micro-fissured rock such as a sandstone. The results of a series of tests carried out to investigate the intrinsic non-linearity of a relatively homogeneous sandstone are presented. To study the deformation of the specimens, they have been loaded cyclically in compression under confining pressures of 0, 150 and 500 p.s.i. The degree of non-linearity varies with the porosity as does the energy dissipation under cyclic loading. Compressibility is found to be essentially path independent and the relationship between compressibility and the total principal stress constitutes a real material property. The real behaviour of sandstone is more complex than that considered in current theories of composite media. The effects of wetting indicate greater non-linearity, hysteresis and residual strains on unloading for a given porosity and pressure. The finite element method is described and extended to take into account material non-linear properties. Stresses in a non-linear flexibly loaded half-space were computed using the finite element method and a variety of non-linear material 2. laws. Results reveal a correspondence with results of field plate bearing tests and the vertical stresses agree remarkably well with the classical linear solution. The horizontal and shear stresses differ more. A lumped parameter model proposed by Ang and Harper (1963) is used to compute stresses and displacements in an excavation problem and the development of plastic regions due to increments of self weight are recorded. This model is found to be efficient and simple for elastic solutions, but must be used with considerable caution when accounting for plastic behaviour.