Failures of Stiffened Ducts Stressed by Temperature

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F17%3A00313984" target="_blank" >RIV/68407700:21110/17:00313984 - isvavai.cz</a>

Výsledek na webu

<a href="http://onlinelibrary.wiley.com/doi/10.1002/cepa.2017.1.issue-2-3/issuetoc" target="_blank" >http://onlinelibrary.wiley.com/doi/10.1002/cepa.2017.1.issue-2-3/issuetoc</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/cepa.530" target="_blank" >10.1002/cepa.530</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Failures of Stiffened Ducts Stressed by Temperature

Popis výsledku v původním jazyce

Steel pipelines are an important part of industrial technology equipment in many sectors. Ducts with a ratio of pipe diameter to wall thickness of up to 150 are generally considered as simple beams, ducts with a higher ratio have to be considered as shell elements. Technical literature provides a number of methods for designing such structures stressed by various kinds of loads. Failures that have occurred in recent past suggest that the existing common design method for industrial piping shows some insufficiencies. This paper is focused on the study of stiffened steel shells stressed by temperature changes. Due to a high temperature load, there is a big temperature deformation of the whole system. This deformation caused by temperature differs within particular parts of the system. As the high temperature source is inside the pipe, the highest temperature is on the inner surface of the shell. The variation of the temperature in the shell and the partial warming of the ring stiffener is caused by heat conduction. Due to the different temperatures of the surrounding environment the stiffener is always colder compared to the shell. The research is focused on the shell behaviour close to the ring stiffener, which represents the area most tending to cracks initiation and their expansion due to the low-cycle fatigue phenomenon. The research procedure consists of several sub-parts. In the first part, the authors focus on determining the thermal load based on the theory of heat transfer. The resulting heat transfer coefficients were verified by measurements performed on the real structure. These findings served as boundary conditions for numerical modelling in Ansys. The resulting values of strain and stress were one of the inputs for the subsequent analysis of lifetime prediction from the viewpoint of low cycle fatigue. The number of cycles to failure (creation of macro-cracks) for various types of structural solutions has been determined in the final part of research.

Název v anglickém jazyce

Failures of Stiffened Ducts Stressed by Temperature

Popis výsledku anglicky

Steel pipelines are an important part of industrial technology equipment in many sectors. Ducts with a ratio of pipe diameter to wall thickness of up to 150 are generally considered as simple beams, ducts with a higher ratio have to be considered as shell elements. Technical literature provides a number of methods for designing such structures stressed by various kinds of loads. Failures that have occurred in recent past suggest that the existing common design method for industrial piping shows some insufficiencies. This paper is focused on the study of stiffened steel shells stressed by temperature changes. Due to a high temperature load, there is a big temperature deformation of the whole system. This deformation caused by temperature differs within particular parts of the system. As the high temperature source is inside the pipe, the highest temperature is on the inner surface of the shell. The variation of the temperature in the shell and the partial warming of the ring stiffener is caused by heat conduction. Due to the different temperatures of the surrounding environment the stiffener is always colder compared to the shell. The research is focused on the shell behaviour close to the ring stiffener, which represents the area most tending to cracks initiation and their expansion due to the low-cycle fatigue phenomenon. The research procedure consists of several sub-parts. In the first part, the authors focus on determining the thermal load based on the theory of heat transfer. The resulting heat transfer coefficients were verified by measurements performed on the real structure. These findings served as boundary conditions for numerical modelling in Ansys. The resulting values of strain and stress were one of the inputs for the subsequent analysis of lifetime prediction from the viewpoint of low cycle fatigue. The number of cycles to failure (creation of macro-cracks) for various types of structural solutions has been determined in the final part of research.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20101 - Civil engineering

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Eurosteel 2017

ISBN

—

ISSN

2509-7075

e-ISSN

2509-7075

Počet stran výsledku

10

Strana od-do

4688-4697

Název nakladatele

Ernst & Sohn

Místo vydání

Berlin

Místo konání akce

Copenhagen

Datum konání akce

13. 9. 2017

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—