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Computational fracture mechanics for reliability of composites at the micro and macro scales

Guillén Hernández, Teresa (2020) Computational fracture mechanics for reliability of composites at the micro and macro scales. Advisor: Paggi, Prof. Marco. Coadvisor: Reinoso Cuevas, Dr. José Antonio . pp. 170. [IMT PhD Thesis]

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Abstract

In recent years, an increasing use of composite materials in aerospace and aeronautical applications has taken place. Fibre reinforced composites materials (FRCs) present high specific strength and stiffness ratios, which can be considered as remarkable advantages with respect to metallic materials. One of the main problems associated with the internal arrangement of fibre reinforced materials regards the numerous and complex failure mechanisms that can occur at different scales of observations. Stemming from these reasons, at present, the analysis and study of fracture in fibre composites constitutes a relevant and recurrent area of research due to the actual needs for the achievement of a higher level of understanding of such fracture phenomena. Within this context, this dissertation presents a new model to simulate fracture in FRCs with the aim of designing safe and durable aircraft structures, for instance: shells, plates or thin filmsubstrate structures. The fundamental computational model used in the present thesis was proposed in (14), devising a seminal combination of the Phase Field approach for brittle fracture and a Cohesive Zone Model for interface failure. In the current research, this computational framework is examined and validated through the numerical simulations of different applications at the micro- and macro-scales: (i) the micro-mechanical inter-fiber failure of composites, the subsequent propagation of failure through the thickness of the laminates arising a macro-crack and (ii) several macro-mechanical applications concerning advanced composite structures (shells, thin film-substrates and Functionally Graded Materials). Derived from the current predictions, it is possible to argue that the current numerical methodology is very suitable for the simulation of fracture in composites at different length scales and allows the preclusion of intricate remeshing techniques or crack tracking algorithms in conjunction with minimizing the mesh-dependent pathology due to its non-local character.

Item Type: IMT PhD Thesis
Subjects: Q Science > QA Mathematics > QA75 Electronic computers. Computer science
PhD Course: Computer science and systems engineering
Identification Number: 10.6092/imtlucca/e-theses/316
Date Deposited: 24 Jul 2020 09:18
URI: http://e-theses.imtlucca.it/id/eprint/316

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