Analysis of reinforcement designs for specials in steel pipelines.

Date
2017-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: This thesis relates to the analysis of reinforced steel pipe specials (tees and lateral tees) for bulk water pipelines. Pipe specials provide a means of dividing and/or uniting ows. Finite element (FE) analyses are performed to evaluate the, experimentally obtained, American Water Works Association's (AWWA) M11 design model that is commonly used. Modelling considerations are discussed with emphasis on stress-strain behaviour, boundary conditions and geometry. The material non-linear behaviour of steel is described, with emphasis on the selection of suitable numerical analysis tools. The purpose of reinforcements for large diameter steel specials are explained and the types of reinforcements are described in detail. Emphasis is placed on the development of a large number of simulated 45 degree lateral tees. Possible model variations and alternative types of reinforcements are brie y looked at. The development of adjustment parameters for M11 designed reinforcements are discussed, with consideration to the mechanical properties of modern steels. The results of physical testing were used to validate the numerical models developed in this study. The deformed shape of the pressurised test piece used in the validation process corresponds to the numerical model and strain measurements correlate well with simulated strains.
AFRIKAANSE OPSOMMING: Hierdie tesis het betrekking tot die ontleding van versterkte staalpypkoppelstukke (T-stukke en laterale T-stukke) vir grootmaat water pyplyne. Pyp koppelstukke maak dit moontlik om vloei in 'n pyplyn te skei en/of te verenig. Eindige element (EE) analises is uitgevoer om die eksperimenteel ontwikkelde M11 ontwerpsmodel van die American Water Works Association (AWWA) , wat algemeen gebruik word, te ontleed. Modellerings aspekte is bespreek met klem op spanning-vervormings gedrag, grenstoestande en geometrie. Die materiaal nie-lineariteit van staal is bespreek, met klem op die seleksie van geskikte numeriese ontleding hulpmiddels. Die doel van versterkings vir groot diameter staalpyp versterkings word verduidelik en die verskillende soorte versterkings word in fyner besonderhede beskryf. Klem word gelê op die ontwikkeling van 'n groot aantal gemodelleerde 45 grade laterale T-stukke. Variasies op modelle en alternatiewe soorte versterkings word vlugtig bespreek. Die ontwikkeling van aanpassings parameters vir M11 ontwerpe versterkings is bespreek met oorweging van die meganiese eienskappe van moderne staal. Die resultate van fisiese toetse word gebruik om die numeriese modelle wat in hierdie studie ontwikkel is te bekragtig. Die vervormde drukbelaste toetsstuk wat gebruik is vir die bekragtigingsproses vergelyk goed met die numeriese model en die gemete vervormings korreleer gunstig met die gesimuleerde vervormings.
Description
Thesis (MScEng)--Stellenbosch University, 2017.
Keywords
Steel pipe industry, Water-pipes, Steel -- Stress corrosion, Finite element analysis, UCTD
Citation