Modelling and behaviour of cylindrical shell structures with helical features

Sadowski, Adam J.; Rotter, J.

doi:10.1016/j.compstruc.2013.11.012

Cited by 20 publications

(11 citation statements)

References 49 publications

(90 reference statements)

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“…A metal wind turbine support tower is typically constructed by welding together individual segments or ‘strakes’ of rolled sheet metal, a process common to other large‐scale cylindrical shell structures such as silos, pressure vessels, liquid‐storage tanks, pipelines and chimneys. The strake edges undergo a slight inward curl as a result of shrinking during post‐weld cooling , leading to a well‐defined geometric imperfection along the line of the weld. Its radial profile w ( y ) may be modelled accurately using the Type ‘A’ axisymmetric weld depression of Rotter and Teng :

w ((), y) = δ_{0} e^{prefix- π (||, y - y_{w}) true/ λ} ([], normalcos ((), \frac{π}{λ} (||, y - y_{w})) + normalsin ((), \frac{π}{λ} (||, y - y_{w}))) where λ = \frac{π \sqrt{r t}}{\sqrt[4]{3 ((), 1 - ν^{2})}}

…”

Section: Modelling Of An Imperfect Wind Turbine Support Tower As a Shellmentioning

confidence: 99%

Seismic analysis of a tall metal wind turbine support tower with realistic geometric imperfections

Sadowski

Cámara

Mariotti

et al. 2016

Earthq Engng Struct Dyn

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analysis of a tall metal wind turbine support tower with realistic geometric imperfections. Earthquake Engineering and Structural Dynamics, 46(2), pp. 201-219. doi: 10.1002/eqe.2785 This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent AbstractThe global growth in wind energy suggests that wind farms will increasingly be deployed in seismically active regions, with large arrays of similarly-designed structures potentially at risk of simultaneous failure under a major earthquake. Wind turbine support towers are often constructed as thin-walled metal shell structures, wellknown for their imperfection sensitivity, and are susceptible to sudden buckling failure under compressive axial loading.This study presents a comprehensive analysis of the seismic response of a 1.5 MW wind turbine steel support tower modelled as a near-cylindrical shell structure with realistic axisymmetric weld depression imperfections. A selection of twenty representative earthquake ground motion records, ten 'near-fault' and ten 'far-field', was applied and the aggregate seismic response explored using lateral drifts and total plastic energy dissipation during the earthquake as structural demand parameters.The tower was found to exhibit high stiffness, though global collapse may occur soon after the elastic limit is exceeded through the development of a highly unstable plastic hinge under seismic excitations. Realistic imperfections were found to have a significant effect on the intensities of ground accelerations at which damage initiates and on the failure location, but only a small effect on the vibration properties and the response prior to damage. Including vertical accelerations similarly had a limited effect on the elastic response, but potentially shifts the location of the plastic hinge to a more slender and therefore weaker part of the tower. The aggregate response was found to be significantly more damaging under near-fault earthquakes with pulse-like effects and large vertical accelerations than far-field earthquakes without these aspects. KeywordsThin metal shell structure, imperfection sensitivity, seismic response, multiple stripe analysis, near-fault ground motions, vertical ground acceleration.

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w ((), y) = δ_{0} e^{prefix- π (||, y - y_{w}) true/ λ} ([], normalcos ((), \frac{π}{λ} (||, y - y_{w})) + normalsin ((), \frac{π}{λ} (||, y - y_{w}))) where λ = \frac{π \sqrt{r t}}{\sqrt[4]{3 ((), 1 - ν^{2})}}

…”

Section: Modelling Of An Imperfect Wind Turbine Support Tower As a Shellmentioning

confidence: 99%

Seismic analysis of a tall metal wind turbine support tower with realistic geometric imperfections

Sadowski

Cámara

Mariotti

et al. 2016

Earthq Engng Struct Dyn

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“…Recently, researchers have studied methods for analytically modeling the buckling of spirally welded circular tubes [68,57,69]. When modeling spirally welded slender shells, both geometric imperfections and residual stresses may follow a helical pattern which presents some modeling complexity in addition to that present for the modeling of slender shells generally.…”

Section: Spirally Welded Steelmentioning

confidence: 99%

Spirally welded steel wind towers: Buckling experiments, analyses, and research needs

Jay

Myers

Torabian

et al. 2016

Journal of Constructional Steel Research

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The most common wind tower structure, a tapered tubular steel monopole, is currently limited to heights of ~80m due to transportation constraints which arise because tower sections are manufactured at centralized plants and transported to site for assembly. The need to transport the sections imposes a limit on their size, whereby maximum tower diameters are dictated by bridge clearances rather than by structural efficiency. New manufacturing innovations, based on automated spiral welding, may enable on-site production of wind towers, thereby precluding transportation limits and permitting the manufacture of taller towers, which can harvest the steadier, stronger winds at higher elevations. Taller towers, however, are expected to have crosssections with slenderness that is uncommon in structural engineering (i.e., diameter-to-thickness ratios up to ~500) and much larger than those of conventionally manufactured towers (i.e.,

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“…Como processo alternativo de fabricação para tubulações, vem sendo usado hoje o processo de fabricação de tubos com costura helicoidal por soldagem a arco submerso [11]. De acordo com Alobaidi e Sandgren [12] e Sadowski e Rotter [13], esse processo de fabricação reduz em muitas vezes o custo com transporte, além de possibilitar a fabricação contínua de tubos com tamanhos maiores do que os comercialmente produzidos. Vantagens como a utilização da mesma largura de bobinas de aço em estoque que pode ser adaptada para construir tubos de vários comprimentos e diâmetros distintos não sendo necessários maiores investimentos para configuração diferente numa mesma produção de tubos, o tornam uma excelente opção no requisito aumento de produtividade e redução de custos.…”

Section: Soldagem Helicoidal De Tubos Produzida Em Campo Do Aço Astm unclassified

“…A fabricação de tubos com costura helicoidal em campo -para uso na construção civil como camisas metálicas -vem sendo desenvolvida atualmente pela empresa MEMPS através do equipamento sobre patente PI0802712-9 A2 [14]. A utilização dessa técnica traz vantagens para o processo produtivo de tubulação, pois agrega os fatores de aumento de produtividade, redução de custos e o alcance de propriedades mecânicas desejáveis em um único projeto [12,13,15]. Na soldagem por fusão, particularmente no processo SAW, trabalha-se com fontes de calor com alto aporte térmico.…”

Section: Soldagem Helicoidal De Tubos Produzida Em Campo Do Aço Astm unclassified

Soldagem Helicoidal de Tubos Produzida em Campo do Aço ASTM A-1018 e sua Correlação com Características Mecânicas e Microestruturais das Juntas Soldadas

et al. 2018

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Este é um artigo publicado em acesso aberto (Open Access) sob a licença Creative Commons Attribution Non-Commercial, que permite uso, distribuição e reprodução em qualquer meio, sem restrições desde que sem fins comerciais e que o trabalho original seja corretamente citado.Resumo: Um problema diversas vezes encontrado na produção de tubos está relacionado ao seu transporte dificultado por suas grandes dimensões. Atrelado a isso, a soldagem de campo é complexa e muitas vezes onerosa. Um processo de fabricação alternativo para tubulações é o processo de formação de tubos com costura helicoidal. Este trabalho propõe estudar as características microestruturais e realizar uma avaliação mecânica destas soldas executadas em campo do aço ASTM A1018. Para alcançar o objetivo do trabalho foram utilizados dois tubos de aço fabricados com chapas de espessura de 12,5 mm e diâmetro nominal de 1200 mm, através do equipamento adaptado para a soldagem em campo pelo processo de soldagem por arco submerso. Após soldagem dos tubos, foram retiradas amostras destes para efetuar as análises de micrografia, macrografia, composição química, dobramento e dureza. A principal diferença apresentada entre as amostras foi o aumento da ferrita acicular e redução da ferrita primária de contorno de grão com o decréscimo do aporte térmico nas microestruturas formadas tanto na zona fundida como na ZTA como apresentado. Observou-se, ainda, mudanças na geometria dos cordões de solda. Por fim, identificou-se que o principal parâmetro que influência nas mudanças microestruturais apresentadas é a corrente de soldagem. Palavras-chave: Tubos helicoidais; Soldagem por arco submerso; Caracterização microestrutural e mecânica.Abstract: A problem commonly found in the production of tubes is related to transportation due its large dimensions. This fact, makes field welding a complex and often costly operation.. An alternative fabrication process for pipes is the process of forming tubes with helical welds. This work proposes to study the microstructural characteristics and perform a mechanical evaluation of these welds performed in field of ASTM A1018 steel tubes. In order to reach the aim, two steel tubes manufactured from sheets with a thickness of 12.5 mm and a nominal diameter of 1200 mm were welded by the process of submerged arc welding through the equipment adapted for field welding. Subsequently, samples were taken to perform characterization by microanalysis. Chemical composition, bending and hardness tests were also conducted. The main difference between the samples was the increase of the acicular ferrite and reduction of the primary ferrite of the grain boundary with the decrease of the thermal contribution in the microstructures formed in the molten zone as in the ZTA as presented. Also, changes in the geometry of the weld beads were observed. Finally, it was identified that the main parameter that influences the microstructural changes presented is the welding current.

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Modelling and behaviour of cylindrical shell structures with helical features

Cited by 20 publications

References 49 publications

Seismic analysis of a tall metal wind turbine support tower with realistic geometric imperfections

Seismic analysis of a tall metal wind turbine support tower with realistic geometric imperfections

Spirally welded steel wind towers: Buckling experiments, analyses, and research needs

Soldagem Helicoidal de Tubos Produzida em Campo do Aço ASTM A-1018 e sua Correlação com Características Mecânicas e Microestruturais das Juntas Soldadas

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