Derivation of relations and analysis of tube bending processes using discontinuous fields of plastic strains. Part I. Derivation of geometric-analytic relationships

• Autorzy: Śloderbach Z.

Identyfikatory

DOI

10.1515/ijame-2015-0028

• Języki publikacji: EN

Abstrakty

EN

The generalized strain scheme in bending metal tubes at bending machines with the use of a mandrel presented in Śloderbach (1999; 2002; 20131,2; 2014) satisfies initial and boundary kinematic conditions of bending, conditions of continuity and inseparability of strains. This paper introduces three formal simplifications gradually imposed into forms of principal components of the generalized strain model giving suitable simplifications of the 1st, 2nd and 3rd types. Such mathematical simplifications cause that the obtained strain fields do not satisfy the condition of consistency of displacements and strain continuity. The simplified methods determine safer values of the wall thickness than those from the generalized continuous strain scheme. The condition of plastic incompressibility was used for the derivation of an expression for distribution of Wall thickness of the bent elbow in the layers subjected to tension and compression for three examples of discontinuous kinematic strain fields.

Słowa kluczowe

EN

bending tubes; three simplifications; strains; wall thickness; discontinuous strain fields

PL

naprężenia; kinematyka; gięcie rur

• Wydawca: Oficyna Wydawnicza Uniwersytetu Zielonogórskiego
• Czasopismo: International Journal of Applied Mechanics and Engineering
• Rocznik: 2015
• Tom: Vol. 20, no. 2
• Strony: 417--426
• Opis fizyczny: Bibliogr. 14 poz., wykr.

Twórcy

autor

Śloderbach Z.

• Opole University of Technology Faculty of Applications of Chemistry and Mechanics 45-036 Opole, Luboszycka 7, POLAND

Bibliografia

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• [6] Śloderbach Z. (1999): A Model for strain geometry evaluation in pipe bending processes. – Engineering Transactions, vol.47, No.1, pp.3-20.
• [7] Śloderbach Z. and Rechul Z. (2000): Effect of strain hardening and normal anisotropy on allowable values of strain and stress in pipe-bending processes. – Journal of Theoretical and Applied Mechanics, vol.38, No.4, pp.843-859.
• [8] Śloderbach Z. (2002): Some problems of mechanics in pipeline bending processes (in Polish). – Publishing House of Wrocław University of Technology, ISBN 83-7085-665-9, Wrocław, pp.1-218.
• [9] Śloderbach Z. (2013): Application of the kinematically admissible fields of plastic deformation in pipe bending processes. Part I. Derivation of Basic Equations and Expressions. – Manufacturing Processes. Actual Problems – 2013. vol.1. Basic Science Applications in Manufacturing Pricesses, Opole University of Technology, ISBN 978-83-64056-37-6, Opole, pp.11-20.
• [10] Śloderbach Z. (2013): Application of the kinematically admissible fields of plastic deformation in pipe bending processes. Part II. Discusion and Analysis of Obtained Results. – Manufacturing Processes. Actual Problems – 2013. vol.1. Basic Science Applications in Manufacturing Processes, Opole University of Technology, ISBN 978-83-64056-37-6, Opole, pp.21-30.
• [11] Śloderbach Z. (2014): A derivation of the genaralized model of plastic strains during bending of metal tubes at bending machines. – International Journal of Applied Mechanics and Engineering, vol.19, No.1, pp.145-163.
• [12] UDT CONDITIONS (WUDT-UC-WO-O/02:10). (2003): Pressure Installations. General Requirements. Bengding Elbows. Strength Calculations (in Polish). – Issue I, Warsaw.
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