Publicação
Low-velocity impact performance of carbon/epoxy and carbon-glass/epoxy auxetic composite laminates for aerospace applications
| Resumo: | Composite laminates, within the realm of aerospace engineering, possess an inherent weakness due to low Through-the-thickness (TTT) properties, increasing the susceptibility for the initiation and propagation of Barely Visible Impact Damage (BVID), under the form of delamination. This type of damage is a common consequence of Low-velocity Impact (LVI) events on aerospace components during the manufacturing, handling and operational stages. Auxetic composite laminates, i.e. laminates with a Negative Poisson’s Ratio (NPR) either on the front - In-plane (IP) - or TTT plane, are regarded as a promising solution to combat LVI-induced delamination damage and ensuing property degradation, via deformation mechanisms that limit or mitigate this issue. The present dissertation focuses on the development of Carbon/Epoxy (C/E) and Carbon-Glass/Epoxy (C-G/E) auxetic laminates, with NPR in the IP or TTT planes, with enhanced LVI resistance capacity and energy absorption. A comprehensive literature review on the topic of auxetic laminates is presented. Moreover, the relevant formulation for the calculation of said Poisson’s ratios is defined and implemented in a MATLAB algorithm, to discretize the full auxetic domain, and identify the most auxetic lay-up sequences. The results of an experimental program for the mechanical characterization of said laminates are shown, with a focus on tensile and LVI (energy absorption) properties of auxetic laminates. A numerical correlation study based on the LVI tests is presented, with the intent to develop a model with good correlation to the experimental LVI case. Overall, analytical, experimental and numerical studies on the effectiveness of the application of auxetic laminates in aerospace components are described, revealing interesting enhancements on energy absorption and delamination limitation for said laminates. |
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| Autores principais: | Veloso, Cristiano José Guimarães |
| Assunto: | Auxeticity Composite laminates Delamination Poisson’s ratio Auxeticidade Laminados compósitos Delaminação Coeficiente de Poisson |
| Ano: | 2024 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Composite laminates, within the realm of aerospace engineering, possess an inherent weakness due to low Through-the-thickness (TTT) properties, increasing the susceptibility for the initiation and propagation of Barely Visible Impact Damage (BVID), under the form of delamination. This type of damage is a common consequence of Low-velocity Impact (LVI) events on aerospace components during the manufacturing, handling and operational stages. Auxetic composite laminates, i.e. laminates with a Negative Poisson’s Ratio (NPR) either on the front - In-plane (IP) - or TTT plane, are regarded as a promising solution to combat LVI-induced delamination damage and ensuing property degradation, via deformation mechanisms that limit or mitigate this issue. The present dissertation focuses on the development of Carbon/Epoxy (C/E) and Carbon-Glass/Epoxy (C-G/E) auxetic laminates, with NPR in the IP or TTT planes, with enhanced LVI resistance capacity and energy absorption. A comprehensive literature review on the topic of auxetic laminates is presented. Moreover, the relevant formulation for the calculation of said Poisson’s ratios is defined and implemented in a MATLAB algorithm, to discretize the full auxetic domain, and identify the most auxetic lay-up sequences. The results of an experimental program for the mechanical characterization of said laminates are shown, with a focus on tensile and LVI (energy absorption) properties of auxetic laminates. A numerical correlation study based on the LVI tests is presented, with the intent to develop a model with good correlation to the experimental LVI case. Overall, analytical, experimental and numerical studies on the effectiveness of the application of auxetic laminates in aerospace components are described, revealing interesting enhancements on energy absorption and delamination limitation for said laminates. |
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