An open-source implementation to predict buckling behaviour of cold-formed sections

Bronkhorst, S-J (2017-03)

Thesis (MScEng)--Stellenbosch University, 2017.

Thesis

ENGLISH ABSTRACT: The deformation and buckling behaviour of cold-formed sections is a popular research topic. It is currently being studied at Stellenbosch University, but only a few tools exist to aid such research of which only one, namely CUFSM [18], is open-source. In this thesis, Finite Strip theory is reviewed to give the reader su cient understanding in order to develop an implementation. A new, object-oriented Finite Strip Method (FSM) implementation is created to demonstrate how the FSM can be used for static analysis of members as well as to predict their buckling behaviour. This implementation is then further expanded to include the ability to do Direct Strength based designs directly from the strength curves it calculates. The implementation is tested and the results are compared to existing FSM and FEM implementations. The results delivered by the implementation were found to be similar to those of CUFSM in terms of buckling analysis and similar to those of FEM in terms of static analysis. A brief overview of the Direct Strength and E ective Width Methods is provided. The design methods are compared by looking at three aspects namely: design e ort, accuracy, and economy. The Finite Strip Method is discussed with emphasis on why this method is favoured as an input for the Direct Strength Method.

AFRIKAANSE OPSOMMING: Die deformasie en knikgedrag van koud-gevormde staal pro ele is 'n popul^ere navorsings onderwerp. Hierdie onderwerp word tans aan die Universiteit van Stellenbosch ondersoek, maar navorsers het 'n berperkte aantal sagteware toepassings tot hulle beskikking, waarvan slegs een, naamlik CUFSM oop bron is. In hierdie tesis word die Eindige Strook teorie hersien om die leser voldoende kennis te bied om hy/sy eie toepassing te ontwikkel. 'n Nuwe objek geori enteerde Eindige Strook implementering word geskep om te demonstreer hoe die Eindige Strook Metode gebruik kan word vir die statiese analise sowel as om die knik gedrag van balke en kolomme te voorspel. Hierdie implementering word dan verder uitgebrei om die vermo e te h^e om Direkte Krag gebasseerde ontwerpe te doen direk vanaf die krag kurwes wat dit genereer. Die toepassing word getoets en die resultate word vergelyk met bestaande Eindige Strook en Eindige Element (EEM) implementerings. Die tesis vind dat die resultate gelewer deur die toepassing soortgelyk is aan daardie van CUFSM in die geval van knik gedrag en soortgelyk aan die EEM in die geval van statiese analise. 'n Vlugtige oorsig van die Direkte Krag en Effektiewe Wydte metodes word voorsien. Hierdie twee ontwerp metodes word vergelyk op grond van drie aspekte naamlik: ontwerp moeite, akuraatheid en ekonomie. Die Eindige Strook Metode word bespreek met klem op hoekom hierdie metode verkies word as 'n inset tot die Direkte Krag Metode.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/100829
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