Finite element modelling of cyclic behaviour of cold-formed steel bolted moment-resisting connections

This paper investigates the accuracy of new finite element modelling approaches to predict the behaviour of bolted moment-connections between cold-formed steel members, formed by using brackets bolted to the webs of the section, under low cycle fatigue. ABAQUS software is used as a modelling platform. Such joints are used for portal frames and potentially have good seismic resisting capabilities, which is important for construction in developing countries. The modelling implications of a two-dimensional beam element model, a three-dimensional shell element model and a three-dimensional solid element model are reported. Quantitative and qualitative results indicate that the three-dimensional quadratic S8R shell element model most accurately predicts the hysteretic behaviour and energy dissipation capacity of the connection when compared to the test results.

Effects of temperature and strain rate on the tensile behaviors of SIMP steel in static lead bismuth eutectic

In order to assess the susceptibility of candidate structural materials to liquid metal embrittlement, this work investigated the tensile behaviors of ferritic-martensitic steel in static lead bismuth eutectic (LBE). The tensile tests were carried out in static lead bismuth eutectic under different temperatures and strain rates. Pronounced liquid metal embrittlement phenomenon is observed between 200 °C and 450 °C. Total elongation is reduced greatly due to the liquid metal embrittlement in LBE environment. The range of ductility trough is larger under slow strain rate tensile (SSRT) test.

Early Implementation of BIM into a Cold-Formed Steel Design/ Fabricator and an Architectural/Planning Consultancy

There is a broad consensus surrounding the ability of building information modelling (BIM) to positively impact a project by enabling greater collaboration. This paper aims to examine the development of BIM and how it can contribute to the evermore present and growing cold-formed steel (CFS) industry. This is achieved thorough a comprehensive literature review and four exploratory interviews with industry experts. Work has been carried out, for the first time, alongside one of the UK’s largest CFS Designer/Fabricators in conjunction with Northern Ireland’s leading Architectural and Town Planning Consultants in the identification and dissemination of information. The capabilities of BIM have been investigated through modeling of simple CFS structures n consultation with the project partners. By scrutinising the literature and associated interviews, the primary opportunities, as well as barriers, of BIM implementation have been investigated in the context of these companies. It is essential to develop greater understanding of the flexibility, adaptability and interoperability of BIM software as the UK construction industry faces a daunting challenge; fully collaborative 3D BIM as required by the UK Government under the “Government Construction Strategy” by 2016 in all public sector projects. This paper, and the wider study that it stems from, approaches the problem from a new angle, from sections of the construction industry that have not yet fully embedded BIM.

Weathering resistance of thin plasma polymer films on pre-coated steel

O trabalho apresentado teve origem no projecto de investigação “Tailored Thin Plasma Polymers Films for Surface Engineering of Coil Coated Steel”, financiado pelo Programa Europeu ECSC Steel Research. Sistemas de aço galvanizado pré-pintado em banda à base de poliéster e poliuretano foram submetidos a um processo de polimerização por plasma onde um filme fino foi depositado de modo a modificar as propriedades de superfície. Foram usados reactores de cátodo oco, microondas e rádio frequência para a deposição do polímero fino. Os sistemas preparados foram analisados de modo a verificar a influência do processo de polimerização por plasma na alteração das propriedades barreira dos sistemas pré-pintados em banda. Foi estudado o efeito dos diferentes passos do processo de polimerização por plasma, bem como o efeito de diferentes variáveis operatórias. A mistura precursora foi variada de modo a modificar as propriedades da superfície de modo a poder vir a obter maior hidrofobicidade, maior resistência a marcas digitais, bem como maior facilidade de limpeza. Os testes foram conduzidos em solução de NaCl 0,5 M. Para o trabalho foram usadas técnicas de análise da morfologia da superfície como Microscopia de Força Atómica e Microscopia Electrónica de Varrimento. As propriedades electroquímicas dos sistemas foram estudadas por Espectroscopia de Impedância Electroquímica. A estrutura dos filmes gerados no processo de polimerização por plasma foi caracterizada por Microscopia de Transmissão Electrónica. A modificação das propriedades ópticas devido ao processo de polimerização por plasma foi também obtida.

Asymmetric rolling of 5182 aluminium alloy and interstitial free steel sheets

This Ph.D. research focuses on asymmetric rolling (ASR), as an alternative method for improving mechanical responses of aluminium-magnesium alloy and interstitial free (IF) steel regarding industrial requirements. Aluminium alloys are attractive materials in various industries due to their appropriate properties such as low density and corrosion resistance; however, their low formability has limited their applications. As formability of aluminium alloys can be improved through texture development, part of this dissertation is dedicated to producing the desired crystallographic texture with the ASR process. Two types of ASR (i.e. reverse and continuous asymmetric rolling) were investigated. The impact of shear deformation imposed by ASR processes on developing the desirable texture and consequently on mechanical behaviours was observed. The developed shear texture increased the normal and also planar anisotropy. Texture evolution during plastic deformation as well as induced mechanical behaviour were simulated using the “self-consistent” and Taylor models. Interstitial free (IF) steel was the second material selected in this dissertation. Since IF steel is one of the most often used materials in automotive industries it was chosen to investigate the effect of shear deformation through ASR on its properties. Two types of reverse and continuous asymmetric rolling were carried out to deform IF steel sheets. The results of optical microscopy and atomic force microscopy observations showed no significant difference between the grains’ morphology of asymmetric and conventionally rolled samples, whereas the obtained results of transmission electron microscopy indicated that fine and equiaxed dislocation cells were formed through the asymmetric rolling process. This structure is due to imposed shear deformation during the ASR process. Furthermore, the mechanical behaviour of deformed and annealed sheets was evaluated through uniaxial tensile tests. Results showed that at low thickness reductions (18%) the asymmetric rolled sample presented higher stress than that of the conventionally rolled sheet; while for higher thickness reductions (60%) the trend was reversed. The texture analyses indicated that intense rolling texture components which developed through 60% thickness reduction of conventional rolling cause a relatively higher stress; on the contrary the fine structure resulting from ASR appears to be the source of higher stress observed after pre-deformation of 18%.

Shear behaviour of steel-fibre-reinforced concrete simply supported beams

The structural behaviour of steel-fibre-reinforced concrete beams was studied using non-linear finite-element analysis and existing experimental data. The work aim was to examine the potential of using steel fibres to reduce the amount of conventional transverse steel reinforcement without compromising ductility and strength requirements set out in design codes. To achieve this, the spacing between shear links was increased while steel fibres were added as a substitute. Parametric studies were subsequently carried out and comparisons were also made with BS EN 1992-1-1 predictions. It was concluded that the addition of steel fibres enhanced the load-carrying capacity and also altered the failure mode from a brittle shear mode to a flexural ductile one. The provision of fibres also improved ductility. However, interestingly it was found that adding excessive amounts of fibres led to a less-ductile response. Overall, the study confirmed the potential for fibres to compensate for a reduction in conventional shear reinforcement.

Hotel Brand Conversions: What Works and What Doesn’t

As many as one-third of U.S. hotels have been converted from one brand to another in recent years, a process that frequently improves the hotel’s financial performance—although that is not always the case. Using data collected between 1994 and 2012 from PKF Hospitality Research, an analysis of brand conversions by 260 hotels shows that hotels moving downscale generally improved their occupancy, and thus their top-line revenue and profit ratios, compared to a control group of 2,750 hotels that did not change brands. However, hotels that moved upscale did not see notable changes in revenue or profit, nor did hotels that moved across their tier, especially when they stayed within their brand family. Two factors seem to drive the financial results for converted hotels—the relative strength of the brand and the fit between the brand and the property.

The Summer Concert Band, 5th Festival of Contemporary Works, July 18, 1951

Concert program for The Summer Concert Band, 5th Festival of Contemporary Works, July 18, 1951

Hollywood and world cinema influences: tracing intertextuality in the works of two contemporary filmmakers from Francophone Africa; Mahamat Saleh Haroun and Abderrahmane Sissako

Don’t tell me the moon is shining; show me the glint of light on broken glass Anton Chekhov Representations of Africa in cinema are almost as old as cinema itself and date back to Hollywood’s silent era. Most early examples feature the continent as a mere exotic backdrop and include The Sheik (Melford 1921), soon followed, in 1926, by George Fitzmaurice’s Son of the Sheik starring Rudolph Valentino. The next decade brought Van Dyke’s Tarzan movies, Robert Stevenson’s King Solomon’s Mines (1937), and, on the European side, Duvivier’s Pépé le Moko (1936). For representations of Francophone Africa by Africans themselves, the viewing public more or less had to wait, however, until decolonisation in the 1960s (with, for example, Sembene Ousmane’s Borom Sarret and La Noire de…, both released in 1966 and, in 1968, Mandabi). Since then Francophone African cinema has come a long way and has diversified into various strands. Between Borom Sarret and Mahamat-Saleh Haroun’s 2006 Daratt, Saison sèche - or the same director’s Un homme qui crie, almost half a century has elapsed. Over this period, films inevitably have addressed a spectrum of visual, ideological and political tropes. They range from unadorned depictions of the newly independent states and their societies to highly aestheticised productions, not to mention surreal and poetic visions as displayed for instance in Djibril Diop Mambéty’s Touki Bouki (1973). Most of the early films send an overt socio-political message which is a clear and explicit denunciation of a corrupt state of affairs (Souleymane Cissé’s Baara, 1977). They aim to trigger strong emotional and political responses from the viewer, in unambiguous support for the film-maker’s stand. Sembene himself declared: “I consider cinema a means of political action” (Murphy 2000: 221). Similarly, the Mauritanian director Med Hondo wishes to “take up this technical medium and to make it a mouthpiece on behalf of [his] fellow Africans and Arabs” (Jeffries 2002: 11). All this echoes the claims of the Fédération Panafricaine des Cinéastes (FEPACI, founded in 1969), an organisation “dedicated to the liberation of Africa”. In sharp contrast to the incipient momentum given Francophonie by Bourguiba, the Nigerien Hamani Diori and the Senegalese Senghor, who invoked a worldwide communauté organique francophone, FEPACI called for “the creation of an aesthetics of disalienation… [using] didactic... forms to denounce the alienation of countries that were politically independent but culturally and economically dependent on the West” (Diawara 1996: 40). Sembene’s Xala (1974) became the blueprint for this, to this day the best-known vein of Francophone African cinema. Thus considered, this pedigree seems a million miles from mainstream global cinema with its overriding mission to entertain. A question therefore arises: to what extent can a cinema that sprang from such beginnings be seen to interface in any meaningful way with a global film industry that, overwhelmingly and for a century, has indeed entertained the world – with Hollywood at its centre?

A Concert of Works by Ross Lee Finney, 1966

Concert Program for A Concert of Works by Ross Lee Finney, 1966

U.W. Percussion and Steel Drum Ensembles, June 2, 2005

Concert Program for U.W. Percussion and Steel Drum Ensembles

What works for Nutrition? Stories of success from Vietnam, Uganda and Kenya

This report discusses the drivers of progress in tackling multiple forms of malnutrition in these three countries: Vietnam, Uganda, and Kenya. It also identifies some of the challenges which pose as barriers to sustaining progress. Finally, it makes recommendations for key stakeholders such as governments of high burden countries, donor governments, development partners, and civil society, on their role to promote further success.

Procedimentos e dinâmicas inerentes ao processo dos concursos públicos e à realização de "empreitadas de obras públicas, em Portugal"

Trabalho de relatório de Estágio de natureza científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Edificações

Determinação de propriedades mecânicas através de ensaios de provetes miniatura, "Small Punch"

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica