PSI - Issue 39

Arturo Pascuzzo et al. / Procedia Structural Integrity 39 (2022) 649–662 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Figure 8. Comparisons in terms of (a) crack trajectories and (b) Stress Intensity Factors (K I , K II ) between the proposed method and numerical approaches proposed by Kim and Paulino (FEM) (Kim and Paulino (2004b)) and Ooi et al. (SB-FEM) (Ooi et al. (2015)) The results show that the proposed strategy agrees quite well with the predictions of the other methodologies. In particular, the agreement in terms of Stress Intensity Factors confirms that the M -integral method can work with success in the framework of the ALE formulation. 5. Conclusions In this work, a novel modelling strategy for simulating crack propagation phenomena in Functionally Graded Materials (FGMs) is proposed. The proposed model joins a Moving Mesh technique based on the Arbitrary Lagrangian-Eulerian formulation (ALE) and the interaction integral method ( M -integral) in a classic FE environment. The ALE serves as an effective tool to adjust the geometry of the computational domain because of the growing cracks. Specifically, the computational nodes around the crack tip are moved according to the conditions prescribed by the standard criteria of fracture mechanics. Differently from standard FE procedures, the proposed strategy permits reducing remeshing events, thus saving relevant computational resources. To identify crack nucleation conditions and the direction of propagation. The M -integral method is used to extract fracture variables at the crack front. Because the finite elements distort during the propagation phase, the M -integral is implemented in the numerical model by using the ALE formulation, thus operating on deforming finite elements. The proposed method is validated by comparisons with numerical data arising from different numeric methods. The results show that the proposed modelling approach reproduces crack paths accurately. Besides, it guarantees rationale predictions of stress intensity factors during mesh movement. Acknowledgements Fabrizio Greco and Paolo Lonetti gratefully acknowledge financial support from the Italian Ministry of Education, University and Research (MIUR) under the P.R.I.N. 2017 National Grant “Multiscale Innovative Materials and Structures” (Project Code 2017J4EAYB; University of Calabria Research Unit). Arturo Pascuzzo gratefully acknowledge financial support from the Italian Ministry of Education, University and Research (MIUR) under the National Grant “PON R&I 2014-2020, Attraction and International Mobility (AIM)”, Project n° AIM1810287,