PSI - Issue 13

Ivica Galić et al. / Procedia Structural Integrity 13 (2018) 2109 – 2113 Galić et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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4. Conclusion

In this paper, a comparison of SIFs for the internal cracks in the body of a pressure valve DN50 PN160 was carried out. The valve body was modelled, meshed, and boundary conditions assigned within commercially available software Abaqus and by using the finite element method. Internal cracks were modelled in the regions within the valve bodies with highest stress concentrations and SIFs were obtained by using either classical FEM formulation or X-FEM. The SIF results which were presented as a function of the angle within the crack were then mutually compared. It can be concluded that the extended finite element method produced more conservative results. In other words, higher stress intensity factors were obtained, meaning shorter fatigue lives are expected. The aforementioned justifies the use of X FEM for geometrically complex shapes such as the pressure valve bodies. In future studies, difference between SIF calculations with FEM and X-FEM will be used to estimate fatigue lives of the valve bodies. References N. Möes, J. Dolbow, T. Belytschko, 1999. A finite element method for crack growth without remeshing, in “ International Journal for Numerical Methods in Engineering “ , 46 (1), pp. 131-150 N. Sukumur, N. Möes, B. Moran, T. Belytschko, 2000. Extended Finite Element Method for Three-Dimensional Crack Modelling, in “ International Journal for Numerical Methods in Engineering “ , 48, pp. 1549 – 1570 M. Stolarska, D. L. Chopp, N. Möes, T. Belytschko, 2001. Modeling crack growth by level sets in the extended finite element method, in “ International Journal for Numerical Methods in Engineering “ , 51 (8), pp. 943-960 G. Yi, T. Yu, T. Q. Bui, C. Ma, S. Hirose, 2017. SIFs evaluation of sharp V-notched fracture by XFEM and strain energy approach, in “ Theoretical and Applied Fracture Mechanics “ X. Sun, G. Chai, Y. Bao, 2017. Ultimate bearing capacity analysis of a reactor pressure vessel subjected to pressurized thermal shock with XFEM, in “ Engineering Failure Analysis “ E. Feulvarch, M. Fontaine, J. Bergheau, 2013. XFEM investigation of a crack path in residual stresses resulting from quenching, in “ Finite Elements in Analysis and Design “ 75, pp. 62-70 S. Kumar, I.V. Singh, B.K. Mishra, 2015. A homogenized XFEM approach to simulate fatigue crack growth problems, in “ Computers and Structures “ 150 pp.1-22 S. Kumar, I.V. Singh, B.K. Mishra, K. Sharma, I.A. Khan, 2016. A Homogenized Multigrid XFEM to Predict the Crack Growth Behavior of Ductile Material Presence of Microstructural Defects, in “ Engineering Fracture Mechanics “ H. Dirik, T. Yalcinkaya, Fatigue Crack Growth Under Variable Amplitude Loading Through XFEM, 21 st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy