Influence of crack presence on operating conditions of pressure vessels with flat endplates

• Autorzy: Szybiński B. , Romanowicz P.

Identyfikatory

DOI

10.5604/12314005.1213557

• Języki publikacji: EN

Abstrakty

EN

The paper discusses influence of crack presence on operating conditions of boilers and pipes. In the study particular attention is paid to the vessels with flat endplates with circular stress relieve grooves. The endplates with such grooves are common alternative for widely used dished ends, particularly for smaller boiler diameters and also for vessels with non-circular cross-sections. The existing codes set the rules how to calculate the circular groove parameters – the groove radius and the location of the arc centre. These design parameters are limited by set of inequalities, which indicate the ranges for admissible radii values and the groove centre positions. The choice of the optimal values for the endplate design parameters has been worked out in recent Authors’ investigations. Such approach provides the minimum stress concentration in the vicinity of the cutout, but this notch area still can be the source of crack nucleation and its propagation leading to the premature fracture of the considered vessel. In standard calculations of pressure boilers, the fracture parameters are not taken into account. The current study concentrates on the assessment of the influence of the crack existence on the stable vessel operation. The cracks existing in inner wall of the vessel are of the main interest, because these are difficult to identify and monitor. In these studies the influence of different parameters like the crack length and orientation, and the fracture toughness were taken into account. The detailed numerical results were obtained by means of the finite element code ANSYS [1] for several crack sizes and locations. The cracks in the weld joining shell and end plate and cracks in the groove area, where the maximum stress concentration appeared were subject of the numerical study. The obtained results show the risk of possible premature failure of boilers with cracks.

Słowa kluczowe

EN

pressure boilers; flat ends; cracks; fracture analysis; FEM

• 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: 2016
• Tom: Vol. 23, No. 1
• Strony: 377---384
• Opis fizyczny: Bibliogr. 11 poz., rys.

Twórcy

autor

Szybiński B.

• Cracow University of Technology Department of Mechanical Engineering Jana Pawła II Avenue 37, 31-864 Kraków, Poland tel.: + 48 123743306, + 48 123743388, fax: + 48 123743360

autor

Romanowicz P.

• Cracow University of Technology Department of Mechanical Engineering Jana Pawła II Avenue 37, 31-864 Kraków, Poland tel.: + 48 123743306, + 48 123743388, fax: + 48 123743360

Bibliografia

• [1] ANSYS, ver.12.1, Swanson Analysis Systems, 2009.
• [2] British-Adopted European Standard, EN12952-3:2001, Water-tube boilers and auxiliary installations, Design and calculation of pressure parts.
• [3] European Standard, EN 13445-3, Unfired pressure vessels – Part 3: Design, CEN, 2002.
• [4] Luedenbach, G., Failure incidents on flat header end caps with stress relief groove and test measures derived from these, VGB PowerTech 7, 2004.
• [5] Schwaigerer, S., Festigkeitsberechnung im Dampfkessel-, Behaelter- und Rohrleitungsbau, 3rd Ed., Springer, 1978.
• [6] 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, 73(3), pp. 183-190, 1997.
• [7] Preiss, R., Rauscher, F., Vazda, D., Zeman, J. L., The flat end to cylindrical shell connection –limit load and creep design, Intern. Journal for Pressure Vessels and Piping, 75(10),pp. 715-726, 1998.
• [8] Szybiński, B., Romanowicz, P., Zieliński, A. P., Numerical and experimental analysis f stress and strains in flat ends of high-pressure vessels, Key Engineering Materials, 490, pp. 226-236, 2012.
• [9] Szybiński, B., Wróblewski, A., Parametric optimization of stress relief groove shape in flat ends of boilers, Journal of Strain Analysis for Engineering Design, 47(1), p. 55-63, 2012.
• [10] Surjya, Kumar, Maiti, Fracture Mechanics, Fundamentals and Applications, Cambridge Univ. Press 2015.
• [11] Dzioba, I, Zowczak, W., Kasińska, J., Pała, T., Badanie własności mechanicznych złączy z niskowęglowych stali Cr-Mo spawanych laserowo, Mechanik, Nr 1, 2016.

Uwagi

PL

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