PSI - Issue 18

Available online at www.sciencedirect.com Structural Int grity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 18 (2019) 630–638

25th International Conference on Fracture and Structural Integrity Stress assessment of single mitered bend using approximate cylindrical shell solutions Yaroslav Dubyk a *, Iryna Seliverstova b , Andrii Bogdan a a IPP-Centre LLC, 8 Bolsunovska str, Kyiv, 01014, Ukraine b G.S. Pysarenko Institute for Problem of Strength, National Academy of Sciences of Ukraine, 2 Tymiriazevska str, Kyiv, 01014, Ukraine Abstract The main idea of the work is to apply the concepts of short and long solutions of the shells theory, and their combined use for the analysis of the stress-strain state of pipelines with angular misaligment of welds. The concepts of short and long solutions are introduced, which make it possible to replace the equation of the eighth order of shells theory, by a system of two equations of the fourth order. The efficiency of the solutions is demonstrated for two load cases (internal pressure and bending moment), analytical results are compared with the FEM solution and experimental data. 25th International Conference on Fracture and Structural Integrity Stress assessment of single mitered bend using approximate cylindrical shell solutions Yaroslav Dubyk a *, Iryna Seliverstova b , Andrii Bogdan a a IPP-Centre LLC, 8 Bolsunovska str, Kyiv, 01014, Ukraine b G.S. Pysarenko Institute for Problem of Strength, National Academy of Sciences of Ukraine, 2 Tymiriazevska str, Kyiv, 01014, Ukraine Abstract The main idea of the work is to apply th concepts of short and long solutions of the shells th ory, and their combined use for th analysis of the stress-strain state of pipelines with angular misaligment of welds. The concepts of short and l ng solutions ar introduced, which mak it p ssible to replace th equation of the eighth order of sh lls theory, by a system of tw equatio s of the fourth order. The efficiency of the solutions is demonstrated for two load cases (internal pressure and bending moment), analytical results are compared with the FEM solution and experimental data.

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: cylindrical shell; angular misalligment; approximate solution; Keywords: cylindrical shell; angular misalligment; approximate solution;

1. Introduction Comparing with the straight pipes bends are more complicated pipe elements, their behavior is characterized by local ovalization of each cross section during bending which results in additional flexibility. The smooth pipe bends are well studied in literature, comparing with mitered bends, which are still used for pipes of big diameter. Mitred bend is formed by conjunction by welding of two oblique sections of initially straight pipes. Its behavior during loading by pressure or bending moment is not evident and poorly described in standards. The goal of this paper is to give a set of general functions based on thin cylindrical shell theory, which will give the opportunity to consider the mitered bend as an element of a piping system. 1. Introduction Comparing with the straight pipes bends are more complicated pipe elements, their behavior is characterized by local ovalization of each cross section during bending which results in additional flexibility. The smooth pipe bends are well studied in literature, comparing with mitered bends, which are still used for pipes of big diameter. Mitred bend is formed by conjunction by welding of two oblique sections of initially straight pipes. Its behavior during loading by pressure or bending moment is not evident and poorly described in standards. The goal of this paper is to give a set of general functions based on thin cylindrical shell theory, which will give the opportunity to consider the mitered bend as an element of a piping system.

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Corresponding author. Tel.: +38-050-990-1227. E-mail address: dubykir@gmail.com * Corresponding author. Tel.: +38-050-990-1227. E-mail address: dubykir@gmail.com

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2019.08.209