Fábio Navalho - Academia.edu (original) (raw)
Papers by Fábio Navalho
O objectivo da presente tese é o estudo e desenvolvimento de um produto, mais concretamente uma p... more O objectivo da presente tese é o estudo e desenvolvimento de um produto, mais concretamente uma protecção para a tíbia, vulgarmente conhecida como caneleira, para assegurar a prática de desporto com contacto fisíco e impactos de baixa velocidade, da forma mais segura possível. O objectivo prendeu-se com a possibilidade de desenvolver algo com melhores características do que existe neste momento no mercado. Isto na sequência de ter sido reconhecido que grande parte das protecções que existem em grandes superfícies comerciais não ser suficiente para a prática de desporto de uma forma segura [15]. Foram realizados vários ensaios a diferentes materiais compósitos produzidos de forma a identificar qual deles seria o melhor em termos de propriedades mecânicas e depois compará-lo com outros materiais de caneleiras existentes no mercado e retirar conclu
Composite laminates subjected to low-velocity impact events on the through-thickness direction ar... more Composite laminates subjected to low-velocity impact events on the through-thickness direction are conveniently studied and disseminated in the open literature. However, in terms of laminate cylindrical shells this subject is less common. Therefore, the main goal of the present work is to study the impact response of laminate composite cylindrical shells composed by different type of fibres. For this purpose, laminates with different configurations (6C, 2C+2K+2C and 2C+2G+2C), where the “number” represents the number of layers used and C=Carbon, K=Kevlar and G=Glass fibre layers, were analysed in terms of static and impact strength. It is possible to conclude that both static and impact performance are strongly influenced by the shells’ configuration. In terms of compressive static strength, the Kevlar hybrid shells present values 53.2% higher than the 6C shells, while the glass hybrid shells present values 17.3% lower. The impact analyses shows, regardless the similarity of the max...
Applied Sciences
Nowadays, due to the complexity and design of many advanced structures, cylindrical shells are st... more Nowadays, due to the complexity and design of many advanced structures, cylindrical shells are starting to have numerous applications. Therefore, the main goal of this work is to study the effect of thickness and the benefits of a carbon composite sandwich cylindrical shell incorporating a cork core, compared to a conventional carbon composite cylindrical shell, in terms of the static and impact performances. For this purpose, static and impact tests were carried out with the samples freely supported on curved edges, while straight edges were bi-supported. A significant effect of the thickness on static properties and impact performance was observed. Compared to thinner shells, the failure load on the static tests increased by 237.9% and stiffness by 217.2% for thicker shells, while the restored energy obtained from the impact tests abruptly increased due to the collapse that occurred for the thinner ones. Regarding the sandwich shells, the incorporation of a cork core proved to be ...
Frattura ed Integrità Strutturale
Composite laminates subjected to low-velocity impact events on the through-thickness direction ar... more Composite laminates subjected to low-velocity impact events on the through-thickness direction are conveniently studied and disseminated in the open literature. However, in terms of laminate cylindrical shells this subject is less common. Therefore, the main goal of the present work is to study the impact response of laminate composite cylindrical shells composed by different type of fibres. For this purpose, laminates with different configurations (6C, 2C+2K+2C and 2C+2G+2C), where the "number" represents the number of layers used and C=Carbon, K=Kevlar and G=Glass fibre layers, were analysed in terms of static and impact strength. It is possible to conclude that both static and impact performance are strongly influenced by the shells' configuration. In terms of compressive static strength, the Kevlar hybrid shells present values 53.2% higher than the 6C shells, while the glass hybrid shells present values 17.3% lower. The impact analyses shows, regardless the similarity of the maximum loads for all configurations, that Kevlar hybrid shells achieved the highest elastic recuperation and the glass hybrid shells the maximum displacement.
O objectivo da presente tese é o estudo e desenvolvimento de um produto, mais concretamente uma p... more O objectivo da presente tese é o estudo e desenvolvimento de um produto, mais concretamente uma protecção para a tíbia, vulgarmente conhecida como caneleira, para assegurar a prática de desporto com contacto fisíco e impactos de baixa velocidade, da forma mais segura possível. O objectivo prendeu-se com a possibilidade de desenvolver algo com melhores características do que existe neste momento no mercado. Isto na sequência de ter sido reconhecido que grande parte das protecções que existem em grandes superfícies comerciais não ser suficiente para a prática de desporto de uma forma segura [15]. Foram realizados vários ensaios a diferentes materiais compósitos produzidos de forma a identificar qual deles seria o melhor em termos de propriedades mecânicas e depois compará-lo com outros materiais de caneleiras existentes no mercado e retirar conclu
Composite laminates subjected to low-velocity impact events on the through-thickness direction ar... more Composite laminates subjected to low-velocity impact events on the through-thickness direction are conveniently studied and disseminated in the open literature. However, in terms of laminate cylindrical shells this subject is less common. Therefore, the main goal of the present work is to study the impact response of laminate composite cylindrical shells composed by different type of fibres. For this purpose, laminates with different configurations (6C, 2C+2K+2C and 2C+2G+2C), where the “number” represents the number of layers used and C=Carbon, K=Kevlar and G=Glass fibre layers, were analysed in terms of static and impact strength. It is possible to conclude that both static and impact performance are strongly influenced by the shells’ configuration. In terms of compressive static strength, the Kevlar hybrid shells present values 53.2% higher than the 6C shells, while the glass hybrid shells present values 17.3% lower. The impact analyses shows, regardless the similarity of the max...
Applied Sciences
Nowadays, due to the complexity and design of many advanced structures, cylindrical shells are st... more Nowadays, due to the complexity and design of many advanced structures, cylindrical shells are starting to have numerous applications. Therefore, the main goal of this work is to study the effect of thickness and the benefits of a carbon composite sandwich cylindrical shell incorporating a cork core, compared to a conventional carbon composite cylindrical shell, in terms of the static and impact performances. For this purpose, static and impact tests were carried out with the samples freely supported on curved edges, while straight edges were bi-supported. A significant effect of the thickness on static properties and impact performance was observed. Compared to thinner shells, the failure load on the static tests increased by 237.9% and stiffness by 217.2% for thicker shells, while the restored energy obtained from the impact tests abruptly increased due to the collapse that occurred for the thinner ones. Regarding the sandwich shells, the incorporation of a cork core proved to be ...
Frattura ed Integrità Strutturale
Composite laminates subjected to low-velocity impact events on the through-thickness direction ar... more Composite laminates subjected to low-velocity impact events on the through-thickness direction are conveniently studied and disseminated in the open literature. However, in terms of laminate cylindrical shells this subject is less common. Therefore, the main goal of the present work is to study the impact response of laminate composite cylindrical shells composed by different type of fibres. For this purpose, laminates with different configurations (6C, 2C+2K+2C and 2C+2G+2C), where the "number" represents the number of layers used and C=Carbon, K=Kevlar and G=Glass fibre layers, were analysed in terms of static and impact strength. It is possible to conclude that both static and impact performance are strongly influenced by the shells' configuration. In terms of compressive static strength, the Kevlar hybrid shells present values 53.2% higher than the 6C shells, while the glass hybrid shells present values 17.3% lower. The impact analyses shows, regardless the similarity of the maximum loads for all configurations, that Kevlar hybrid shells achieved the highest elastic recuperation and the glass hybrid shells the maximum displacement.