bachelorThesis
Uma introdução sobre os efeitos do Coeficiente de Poisson Negativo e conceitos de desenvolvimento para estruturas têxteis auxéticas
Fecha
2022-06-18Registro en:
COUTO, Alan Franco do. Uma introdução sobre os efeitos do Coeficiente de Poisson Negativo e conceitos de desenvolvimento para estruturas têxteis auxéticas. 2022. Trabalho de Conclusão de Curso (Bacharelado em Engenharia de Materiais) - Universidade Tecnológica Federal do Paraná, Londrina, 2022.
Autor
Couto, Alan Franco do
Resumen
The auxetic behavior, notably the lateral expansion of a material or structure under longitudinal tension, promotes unique properties that result from the Negative Poisson Ratio (NPR), such as greater fracture toughness, hardness, abrasion resistance and compressibility, in accordance to the Classical Theory of Elasticity. This work aimed to introduce the effects of NPR through a tautological-corroborative bibliographic review. Aspects of the elastic behavior of materials and their correlations with the physical principles of Poisson Ratio, the main models and structures proposed in the literature to obtain the NPR and the possibilities for developing metamaterials that present NPR were presented, specially via textile technologies. Furthermore, the main historical context on developments of auxetic materials was presented, ranging from the scope of scientific publications and main authors, to naturally occurring auxetic materials and the birth of their scientific interest as metamaterials. Studies where woven fabrics were designed through yarns with auxetic properties (HAYs), non-woven fabrics were de-signed through micro-machining of auxetic structure in its extension, weft and warp knitted fabrics were designed with auxetic loop structures, and auxetic braids (BAYs) were designed using braiding technology modifications were presented. The research emphasized that there has been a growing trend interest of auxetic behavior since 1987, when the first study and development of auxetic material with scientific interest was published, but most of these studies are abroad Brazil. Thus, it was attested that in Brazil this thematic deserves greater relevance and it’s a unique opportunity for new researches. It is proposed that the scientific community on the subject in the country reunite to create a specific journal for auxetic materials, whose suggested title remains "Auxetica", providing opportunities for expansion and local development in auxetic ma-terials.