No description available.

Thesis (MScEng)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: AP230 of STEP is an application protocol for structural steel-framed buildings. Product data relating to steel structures is represented in a model that captures analysis, design and manufacturing views. The information requirements described in AP230 were analysed with the purpose of identifying a subset of entities that are essential for the description of simple industrial steel frames with the view to being able to describe the structural concept, and to perform the structural analysis and design of such structures. Having identified the essential entities, a relational database model for these entities was developed. Planning, analysis and design applications will use the database to collaboratively exchange data relating to the structure. The comprehensiveness of the database model was investigated by mapping a simple industrial frame to the database model. Access to the database is provided by a set of classes called the database representative classes. The data-representatives are instances that have the same selection identifiers and attributes as corresponding information units in the database. The datarepresentatives' primary tasks are to store themselves in the database and to retrieve their state from the database. A graphical user interface application, programmed in Java, used for the description of the structural concept with the capacity of storing the concept in the database and retrieving it again through the use of the database representative classes was also created as part of this project. / AFRIKAANSE OPSOMMING: AP230 van STEP is 'n toepassingsprotokol wat staal raamwerke beskryf. Die produkdata ter beskrywing van staal strukture word saamgevat in 'n model wat analise, ontwerp en vervaardigings oogmerke in aanmerking neem. Die informasie vereistes, soos beskryf in AP230, is geanaliseer om 'n subset van entiteite te identifiseer wat noodsaaklik is vir die beskrywing van 'n eenvoudige nywerheidsstruktuur om die strukturele konsep te beskryf en om die struktuur te analiseer en te ontwerp. Nadat die essensiële entiteite geïdentifiseer is, is 'n relasionele databasismodel van die entiteite geskep. Beplanning, analise en ontwerptoepassings maak van die databasis gebruik om kollaboratief data oor strukture uit te ruil. Die omvattenheid van die databasis-model is ondersoek deur 'n eenvoudige nywerheidsstruktuur daarop afte beeld. Toegang tot die databasis word verskaf deur 'n groep Java klasse wat bekend staan as die verteenwoordigende databasis klasse. Hierdie databasis-verteenwoordigers is instansies met dieselfde identifikasie eienskappe as die ooreenkomstige informasie eenhede in die databasis. Die hoofdoel van die databasis-verteenwoordigers is om hulself in die databasis te stoor asook om hul rang weer vanuit die databasis te verkry. 'n Grafiese gebruikerskoppelvlak, geprogrammeer in Java, is ontwikkel. Die koppelvlak word gebruik om die strukturele konsep te beskryf, dit te stoor na die databasis en om dit weer, met behulp van die databasis-verteenwoordigers, uit die databasis te haal.

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Civil Engineering / Doctoral / Doctor of Philosophy

Recent tragedies involving the collapse of several large and prominent buildings have brought international attention to the subject of progressive collapse, and the field of structural engineering is actively investigating ways to better protect structures from such catastrophic failures. One focus of these investigations is the behavior and performance of shear tab connections in steel structures during progressive collapse events. The shear tab, a simple connection, is typically modeled as a perfect pin in standard design, but in progressive collapse analysis, a much more accurate model of its true behavior and limits is required. This report documents the development of a simple yet accurate shear tab model and its use in understanding the behavior and limits of shear tab connections in column removal scenarios. Particular attention is paid to the connections’ axial force limit state, an aspect of behavior that is typically unimportant in standard design. / text

Photovoltaic vehicles are designed to harness solar energy and use it for self-propulsion. In order to collect sufficient energy to propel a passenger, a relatively large photovoltaic array is required. Controlling the loads imparted by the array and the body that supports it, while protecting the passenger and minimizing vehicle weight, presents a unique set of design challenges. Weight considerations and geometric constraints often lead system designers toward unconventional structural solutions. This report details analytical and experimental processes aimed at proving the concept of integrating aluminum space-frame elements with composite panels. Finite element analysis is used to simulate load conditions, and results are compared with empirical test data. / text

No description available.

The last 100 years have seen biblical studies practically dominated by diachronic/historical methodologies, Amos studies have a long tradition of being read within a diachronic framework. The result of this has been an unfortunate fragmentation of the text. Within the last 40 years or so there has been a resurgence of literary studies that treat the text wholistically. Nevertheless, in research that has been done in literary studies a divergence with regard to the structure of the book as well as the function and meaning of some of its units still exists. For this reason it is necessary to approach the problem from a fresh perspective. The purpose of this thesis is to demonstrate the literary unity of Amos 3-6. In my work I show not only the legitimacy, but also the superiority of a synchronic reading of Amos 3-6 when reading the text as a whole. The book of Amos enjoys perhaps the most scholarly interest among all of the twelve prophets, which has resulted in a large body of secondary literature. Within the book of Amos, chapters 3-6 provide a closed unit which contains the major message of the book. For this reason, these four chapters afford a suitable text to apply my reading as well as a platform on which to dialogue with secondary sources. The methodology used in this thesis is a close reading of the present form of the Masoretic Text. A major part of the work is structural analysis. Through the analysis I was able to identify meaningful units that I used for my reading of the text. In this reading I looked at keywords and semantic fields, themes, repetition, parallelism, imagery, speakers and addressees, rhetorical techniques and the overall flow of the text. In my study I have shown how Amos 3-6 should be divided into three independent yet closely related units: Amos 3:1-15; 4:1-13 and 5:1-6:14. Recognition of the structure and craftsmanship of the text draws out the singular message of Amos 3-6; that Israel could no longer avoid Yahweh’s judgment for their oppression of the poor. Even if my main conclusion is similar both to scholars who work in diachronic as well as synchronic studies, my conclusion treats the entirety of Amos 3-6 and concludes that all units within it are vital to the whole and contribute to this message of judgment. My thesis offers a solution to the fragmentary text resultant from diachronic methods as well as a corrective to synchronic readings that inadequately structure the book, resulting in an unsatisfactory overall picture of the structure and meaning of Amos 3-6.

This thesis focuses on permanent magnet "direct drive" electrical generators for wind turbines with large power output. A variety of such generator topologies is reviewed, tested and optimised in an attempt to increase their potential as commercial concepts for the wind industry. Direct drive electrical generators offer a reliable alternative to gearbox drivetrains. This novel technology reduces energy loses thus allowing more energy to be yield from the wind and decreases the maintenance cost at the same time. A fundamental issue for these generators is their large size which makes them difficult to manufacture, transport and assembly. A number of structural designs have been suggested in the literature in an attempt to minimise this attribute. A set of design tools are set out in an attempt to investigate the structural stiffness of the different permanent magnet direct drive generator topologies against a number of structural stresses that apply to such wind turbine energy converters. Optimisation techniques, both analytical and structural, are also developed for minimising the total mass of a variety of "directly driven" machines with power output of 5MW or greater. Conventional and promising generator designs are modelled and optimised with the use of these optimisation techniques. The topologies under examination are then compared in terms of structural mass, stiffness and cost. As the number of wind turbine manufactures who adopt the direct drive concept increases, it is important to outline the unique characteristics of the different topologies and increase their manufacturing potential. Discussions and conclusions will provide an indication of the design solutions that could help decrease the mass and cost of such machines.