Design modifications of pressure boilers with flat endplates with stress relief groove

• Autorzy: Szybiński B. , Wygoda M.

Identyfikatory

DOI

10.5604/01.3001.0010.3090

• Języki publikacji: EN

Abstrakty

EN

Stress concentration is still present in the vicinities of structural notches in engineering structures. Zones with higher level of stress are particularly dangerous for structures subjected to fatigue or dynamic loads. The vessels with flat endplates with stress relief grooves are the common examples of such structures. Unfortunately, no clear evidence is given in existing codes how optimally to choose the circular groove radius and the optimal value of that radius depends on the dimensions of the boiler, operating conditions and the material used in manufacturing. Additionally, commonly used grooves with circular shapes are not optimal. Series of experimental tests, numerical or analytical studies presented in numerous articles confirmed these facts. In the presented article, the Authors proposed two-stage modification of the investigated vessel. The first step relies on change of the shape of the groove in the endplate, which provides certain reduction of stress concentration but still plastic deformations in the groove vicinity are not eliminated. The second step of the design modification is proposed for the boiler with the optimal elliptic groove configuration. In this step, some material is added around the top of the outer edge of the endplate. Two simple shapes are proposed for these parts - the short cylindrical ring or alternatively the circular ring welded on the top the endplate is used. For both concepts, the search of optimal dimension/parameters is performed. The numerical results of that study clearly show that the full elimination of plastic deformations near the groove is possible. The numerical analysis and optimizations were made with the well- established finite element software ANSYS, which is accepted by commonly used codes for designing of pressure vessels.

Słowa kluczowe

EN

pressure boilers; flat ends; stress concentration; FEM analysis

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2017
• Tom: Vol. 24, No. 3
• Strony: 309--316
• Opis fizyczny: Bibliogr. 14 poz., rys.

Twórcy

autor

Szybiński B.

• Cracow University of Technology Faculty of Mechanical Engineering Jana Pawła II Av. 37, 31-864 Krakow, Poland tel.: + 48 12 3743388, + 48 12 3743382, fax: + 48 12 3743360

autor

Wygoda M.

• Cracow University of Technology Faculty of Mechanical Engineering Jana Pawła II Av. 37, 31-864 Krakow, Poland tel.: + 48 12 3743388, + 48 12 3743382, fax: + 48 12 3743360

Bibliografia

• [1] European Standard, EN 12952-3:2001, Water-tube boilers and auxiliary installations. Design and calculation of pressure parts, 2001.
• [2] European Standard, EN 13445-3, Unfired pressure vessels – Part 3: Design, CEN, 2002.
• [3] ANSYS, ver.12.1, Swanson Analysis Systems, 2009.
• [4] Błachut, J, Magnucki, K, Strength, Stability, and Optimization of Pressure Vessels: Review of Selected Problems, Applied Mechanics Review, Vol. 61, Nov. 2008.
• [5] Burchill, M., Heller, M., Optimal notch shapes for loaded plate, Journal of Strain Analysis for Engineering Design, Vol. 39 (1), pp. 99-116, 2003.
• [6] Luedenbach, G., Failure incidents on flat header end caps with stress relief groove and test measures derived from these, VGB PowerTech 7, 2004.
• [7] Lewiński, J, Magnucki, K, Shaping of a middle surface of a dished head of a circular pressure vessel, Journal of Theoretical and Applied Mechanics, Vol. 48 (2), pp. 297-307, 2010.
• [8] Muc, A., Muc-Wierzgoń, M., An evolution strategy in structural optimization problems for plates and shells, Composite Structures, Vol. 94, pp. 1461-1470, 2012.
• [9] Pedersen, N. L., Pedersen, P., Design of notches and grooves by means of elliptic shapes, Journal of Strain Analysis for Engineering Design, Vol. 43 (1), pp. 1-14, 2008.
• [10] Preiss, R., Stress concentration factors of flat end to cylindrical shell connection with a fillet or stress relief groove subject to internal pressure. Intern. Journal for Pressure Vessels and Piping, Vol. 73 (3), pp. 183-190, 1997.
• [11] Szybiński, B., Wróblewski, A., Parametric optimization of stress relief groove shape in flat ends of boilers, Journal of Strain Analysis for Engineering Design, Vol. 47 (1), pp. 55-63, 2012.
• [12] Szybiński, B., Romanowicz, P., Zieliński, A. P., Numerical and experimental analysis of stress and strains in flat ends of high-pressure vessels, Key Engineering Materials, Vol. 490, pp. 226-236, 2012
• [13] Szybiński, B., Design of flat ends in pressure boilers with circular and elliptical stress relieve grooves, Applied Mechanics and Materials, Vol. 477-478, pp. 49-53, 2014.
• [14] Szybiński, B., Parametric and topological optimization of different designs of flat ends in pressure vessels, Recent Advances in Mechanics and Materials in Design (ed.: J. F. Silva Gomes, S. A. Meguid), Ponta Delgada, Portugal 2015.

Uwagi

PL

Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017).