The wide spread use of limit states design procedures in both the Canadian and American steel design codes has created a need for a better understanding of how structures behave. Current design practice, however, allows and often encourages engineers to use an approximate linear analysis to determine the member forces in a structure. This is then followed by an even more approximate amplification of forces through the use of several design equations. It is believed that this practice is no longer acceptible as more accurate second-order computer programs have become a very practical alternative. With this as motivation, this thesis will provide a comparison between a second-order computer program available at the University of British Columbia called ULA (Ultimate Load Analysis) and the Canadian and American building code designs, CAN3-S16.1-M84 and LRFD 1986 respectively. It was felt that ULA should be verified, even though the theory it is based on is well established. Thus, ULA was used to generate a load versus L/r curve for a pin ended column (with the parameters modified slightly to allow direct comparison with the curves available in the codes). ULA was then used to predict load-deflection curves for two existing test frames. The resulting curves compared well with the test data. To ensure simplicity, the building codes make several approximations in the derivation of their design equations. This results in the equations being applicable to a very narrow range of structures. Specifically, the equations apply to rigidly connected frames in which all of the columns reach their critical buckling load simmultaniously. Consequently, the results from ULA were compared to the codes for structures of this type. It was found that the codes were conservative for these structures in relation to the results from ULA, yet the amount of conservatism varied greatly between structures. That is, the codes are not consistant in how conservative they are. Results from ULA were then compared to the codes for structures that do not satisfy all of the code limitations. Alhough using the codes to design structures beyond the limit of applicability is not a recommended practice, engineers do use the codes to design all types of structures, with little appreciation for the applicability limits. Consequently, it was deemed appropriate to extend this study to such structures. Though only a few were investigated, it was found that the codes were unreliable, being highly conservative, very accurate, or in one case highly unconservative when compared to the results from ULA. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

no abstract provided by author / Master of Science

Thesis (MScEng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Connections are a vitally important part of any structural framework. Thisstatement may seem obvious, yet it is surprisinghow often insufficient attention is given to the design of this essential aspect of steelwork projects. This thesis concentrates on developing a specification for designing steel connections with the main emphasis on the practical and economical design of typical connections. The design methods of the specification are developed according to the new South African design code which is currently in draft form, namely SANS10162:Code of Practice for the Structural Use of Steel: Part 1: Limit States Design of hot-rolled steelwork - 2002. An object-oriented framework and associated graphical user interface for designing the connections are developed and implemented. The primary objectives of the implemented framework are: • Being generic in the sensethat it allows for easy addition of additional connection types, • To implement the design paradigm of the South African code, without fixing specific parameter values programmatically in the implementation and • To build on an existing architecture that allows for structural analysis,structural steel member design and distributed collaboration in the design process. / AFRIKAANSE OPSOMMING: Verbindings vorm In uiters belangrike deel van enige staal struktuur. Alhoewel hierdie stelling dalk vanselfsprekend mag wees, is dit egter verbasend hoe selde voldoende aandag aan die ontwerp van hierdie essensiëleaspek van staalwerk projekte gegee word. Hierdie tesis konsentreer op die ontwikkeling van In spesifikasievir die ontwerp van staal verbindings met die oog op praktiese en ekonomiese ontwerp van tipiese verbindings. Hierdie ontwerpmetodes isgebasseer op die nuwe Suid Afrikaanse ontwerpkode wat tans in proef-vorm is, naamlik SANS 10162: Gebruikskode vir Stoa/bouwerk: Dee/I: Grenstoestandontwerp vir warmgewa/ste staa/werk - 2002. In Objek orienteerde raamwerk en In geassosieerde grafiese gebruikerskoppelvlak word ontwikkel en geimplimenteer. Die primêre mikpunte van hierdie geimplimenteerde raamwerk is: • Om generies te wees in die sin dat dit die byvoeging van addisionele verbinding tipes toelaat, • Om die paradigma van die Suid Afrikaanse kode te implimenteer sonder om enige waardes van spesifieke parameters programmaties vas te lê, en • Om dit op In bestaande argitektuur te bou wat strukturele analise, strukturele ontwerp en verspreide samewerking in die ontwerpproses toelaat.

Thesis (MScEng)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Connections are a vitally important part of any structural framework. Thisstatement may seem obvious, yet it is surprisinghow often insufficient attention is given to the design of this essential aspect of steelwork projects. This thesis concentrates on developing a specification for designing steel connections with the main emphasis on the practical and economical design of typical connections. The design methods of the specification are developed according to the new South African design code which is currently in draft form, namely SANS10162:Code of Practice for the Structural Use of Steel: Part 1: Limit States Design of hot-rolled steelwork - 2002. An object-oriented framework and associated graphical user interface for designing the connections are developed and implemented. The primary objectives of the implemented framework are: • Being generic in the sensethat it allows for easy addition of additional connection types, • To implement the design paradigm of the South African code, without fixing specific parameter values programmatically in the implementation and • To build on an existing architecture that allows for structural analysis,structural steel member design and distributed collaboration in the design process. / AFRIKAANSE OPSOMMING: Verbindings vorm In uiters belangrike deel van enige staal struktuur. Alhoewel hierdie stelling dalk vanselfsprekend mag wees, is dit egter verbasend hoe selde voldoende aandag aan die ontwerp van hierdie essensiëleaspek van staalwerk projekte gegee word. Hierdie tesis konsentreer op die ontwikkeling van In spesifikasievir die ontwerp van staal verbindings met die oog op praktiese en ekonomiese ontwerp van tipiese verbindings. Hierdie ontwerpmetodes isgebasseer op die nuwe Suid Afrikaanse ontwerpkode wat tans in proef-vorm is, naamlik SANS 10162: Gebruikskode vir Stoa/bouwerk: Dee/I: Grenstoestandontwerp vir warmgewa/ste staa/werk - 2002. In Objek orienteerde raamwerk en In geassosieerde grafiese gebruikerskoppelvlak word ontwikkel en geimplimenteer. Die primêre mikpunte van hierdie geimplimenteerde raamwerk is: • Om generies te wees in die sin dat dit die byvoeging van addisionele verbinding tipes toelaat, • Om die paradigma van die Suid Afrikaanse kode te implimenteer sonder om enige waardes van spesifieke parameters programmaties vas te lê, en • Om dit op In bestaande argitektuur te bou wat strukturele analise, strukturele ontwerp en verspreide samewerking in die ontwerpproses toelaat.

M.Ing. (Civil Engineering) / The purpose of this investigation was to develop the basic information necessary for formulating creteria for the design of Type 3CR12 steel hot-rolled sections as columns. The mechanical properties needed for structural design are established. Investigations into the behaviour of axially loaded compression members indicated that the overall column buckling of compression members may be predicted with confidence by the tangent modulus approach. Finally simplified design recommendations are made for the design of Type 3CR12 steel hot-rolled columns. The need for future research are identified.