PSI - Issue 41

Daniele Gaetano et al. / Procedia Structural Integrity 41 (2022) 439–451 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 9. Multiscale Numerical Simulation of the mixed-mode fracture test on a L-shaped composite panel: (a) deformed configuration and first principal stress map at the final simulation step; (b) force vs displacement curve.

4. Conclusions In this work, a novel hybrid cohesive/volumetric multiscale finite element model is proposed for performing efficient failure analyses of fiber-reinforced composite structures. Such a strategy adopts a Diffuse Interface Model (for the numerical simulation of multiple cracking at both micro- and macro-scales) used in conjunction with a continuous/discontinuous nonlinear homogenization scheme. The main advantage of this multiscale approach over more sophisticated ones is the adoption of very efficient operational steps to be performed within an off-line simulation stage. The present model has been applied for analyzing the failure of fiber-reinforced structures subjected to transverse cracking (including matrix cracking and fiber/matrix debonding). In particular, two case studies have been presented in this work, referring to Mode-I and Mixed-Mode fracture conditions, in order to demonstrate the versatility and the generality of the proposed approach. Furthermore, suitable comparisons with a fully detailed model have shown that the proposed multiscale strategy is very efficient from the computational point of view, while preserving a high numerical accuracy, in terms of both overall load-carrying capacity and average cracking pattern. In particular, the errors reported on the peak load were always less than 4%, thus being fully acceptable for engineering purposes. As potential further applications of this approach, its integration within a more general virtual testing framework for arbitrary composite materials and structures could be proposed, also including its synergistic application together with structural optimization methodologies (see, for instance, Lonetti and Pascuzzo (2014), Bruno et al. (2016b)), aimed at designing tailored micro- and nano-structures with superior mechanical properties, especially in terms of overall strength, toughness, flexibility and wave propagation control. Acknowledgements Fabrizio Greco and Paolo Nevone Blasi 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). Lorenzo Leonetti and 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 Code AIM1810287, University of Calabria”.