PSI - Issue 12

Venanzio Giannella et al. / Procedia Structural Integrity 12 (2018) 404–415 V. Giannella/ Structural Integrity Procedia 00 (2018) 000 – 000

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Figure 11. FEM submodel with the propagated crack.

6. Conclusions

A coupled FEM-DBEM procedure, based on the superposition principle applied to fracture mechanics, has been adopted to simulate a fracture process on a real aircraft gas turbine engine. Such an approach is fully automated and allows to predict SIFs and then the whole crack-growth and path with high accuracy. The initial crack has been inserted in the most critical point, as acquired from the experimental outcomes, of the compressor stage of interest. A good agreement between the numerical crack paths calculated with FEM-DBEM and FEM-FEM approaches has been shown, although the numerical paths did not match the experimental paths, probably because of the lack of allowance for relevant loading conditions coming from e.g. pressure on blades, residual stresses, transients, blade vibrations, etc. Some of the aforementioned effects will be introduced in the near future to improve the correlation between numerical and experimental outcomes. Maligno, A.R., Citarella, R., Silberschmidt, V.V., Soutis, C., 2015. Assessment of Structural Integrity of Subsea Wellhead System: Analytical and Numerical Study. Frattura ed Integrità Strutturale 31 97-119. Citarella, R., Lepore, M., Maligno, A., Shlyannikov, V., 2015a. FEM simulation of a crack propagation in a round bar under combined tension and torsion fatigue loading. Frattura ed Integrità Strutturale 31 138-147. Citarella, R., Lepore, M., Shlyannikov, V., Yarullin, R., 2014a Fatigue surface crack growth in cylindrical specimen under combined loading. Engineering Fracture Mechanics 131, 439 – 453. Citarella, R., Perrella, M., 2005. Multiple surface crack propagation: numerical simulations and experimental tests. Fatigue Fract Eng Mater Struct 28, 135 – 48. Calì, C., Citarella, R., Perrella M., 2003. Three-dimensional crack growth: numerical evaluations and experimental tests, in: ”E uropean Structural Integrity Society ”. In: Biaxial/Multiaxial Fatigue and Fracture, Edited by Andrea Carpinteri, Manuel de Freitas and Andrea Spagnoli, 31(3), 3 504. Citarella, R., Giannella, V., Lepore, M., Dhondt, G., 2018. Dual boundary element method and finite element method for mixed ‐ mode crack propagation simulations in a cracked hollow shaft. Fatigue & Fracture of Engineering Materials & Structures 41(1), 84-98. Citarella, R., Cricrì, G., 2014b. Three-Dimensional BEM and FEM Submodelling in a Cracked FML Full Scale Aeronautic Panel. Appl Compos Mater 21 (3) 557-577. Citarella, R., Lepore, M., Fellinger, J., Bykov, V., Schauer, F., 2013. Coupled FEM-DBEM method to assess crack growth in magnet system of Wendelstein 7-X. Fracture and Structural Integrity 26, 92-103. Citarella, R., Cricrì, G., Lepore, M., Perrella, M., 2014c. Assessment of Crack Growth from a Cold Worked Hole by Coupled FEM-DBEM Approach. Key Engineering Materials 577-578, 669-672 Trans Tech Publications, Switzerland. References