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Abstract(s)
O Abeto de Douglas é uma espécie de madeira conífera nativa da América do Norte
que possui uma vasta utilização na construção sendo também aplicada como elemento
estrutural. O presente trabalho de dissertação tem por objetivo caracterizar as propriedades
físicas e mecânicas da madeira em estudo e averiguar possíveis fatores que podem influenciar
tais particularidades, como por exemplo os defeitos que estão presentes na maioria de tais
elementos. Numa primeira fase do trabalho, visou-se determinar as propriedades mecânicas do
abeto de Douglas, de acordo com EN 408 através de ensaios de flexão e compressão paralela
ao grão onde foi possível obter o módulo de elasticidade e as suas respectivas resistências.
Convém mencionar que nos testes de compressão utilizaram-se dois métodos para determinação
do módulo de elasticidade, o primeiro foi por meio de correlação digital de imagem e o segundo
foi empregue um extensômetro mecânico. Em uma segunda fase foi pretendido definir o teor
de humidade e as densidades básica e aparente do material, que estão entre as principais
características físicas da madeira e que possuem grande influência sobre as demais
propriedades, todos os procedimentos foram realizados em conformidade com a ISO 13061.
Afim de analisar a viabilidade das vigas, foram realizados testes de flexão em elementos de
escala real utilizados na construção. Os valores de resistência e módulo de elasticidade obtidos
nessa etapa foram comparados com os valores determinados com os outros ensaios de flexão.
Com base nas EN 384 e EN 338 determinaram-se os valores característicos possibilitando a
partir dos mesmos a relacionar a madeira a uma classe de resistência definida como C18.
Finalmente foi elaborada uma ficha técnica, para madeira “Abeto de Douglas” contendo todos
os resultados obtidos em relação às suas propriedades físicas e mecânicas bem como sua classe
de resistência.
Douglas Fir is a North American native conifer species that has wide use in construction and is also applied as a structural element. The objective of this dissertation was to determine some of the physical and mechanical properties of the wood under study and to investigate possible factors that may influence such particularities, as e.g the defects that are present in most of these elements. In a first stage, it was aimed to determine the mechanical properties of Douglas fir according to EN 408 through tests bending and compression parallel to grain where it was possible to obtain the modulus of elasticity and its respective strengths. It should be mentioned that in the tests compression parallel to grain, two methods of determination of the modulus of elasticity were used, in which the first was by digital image correlation and the second was employed a mechanical extensometer. Also in order to analyze the viability of the beams, flexural tests were performed on real scale elements used in the construction. The values of strength and modulus of elasticity obtained in this step were compared with the values determined with the other flexural tests. In a second phase it was intended to define the moisture content and the basic and apparent densities of the material, which are among the main physical characteristics of the wood and that have great influence on the other properties, all procedures were performed in accordance with ISO 13061. Based on the EN 384 and EN 338 the characteristic values were determined, allowing them to relate the wood to a resistance class defined as C18. Finally, a technical data sheet was prepared containing all the results of its physical and mechanical properties obtained on the wood. of the studied species, as well as its resistance classification.
Douglas Fir is a North American native conifer species that has wide use in construction and is also applied as a structural element. The objective of this dissertation was to determine some of the physical and mechanical properties of the wood under study and to investigate possible factors that may influence such particularities, as e.g the defects that are present in most of these elements. In a first stage, it was aimed to determine the mechanical properties of Douglas fir according to EN 408 through tests bending and compression parallel to grain where it was possible to obtain the modulus of elasticity and its respective strengths. It should be mentioned that in the tests compression parallel to grain, two methods of determination of the modulus of elasticity were used, in which the first was by digital image correlation and the second was employed a mechanical extensometer. Also in order to analyze the viability of the beams, flexural tests were performed on real scale elements used in the construction. The values of strength and modulus of elasticity obtained in this step were compared with the values determined with the other flexural tests. In a second phase it was intended to define the moisture content and the basic and apparent densities of the material, which are among the main physical characteristics of the wood and that have great influence on the other properties, all procedures were performed in accordance with ISO 13061. Based on the EN 384 and EN 338 the characteristic values were determined, allowing them to relate the wood to a resistance class defined as C18. Finally, a technical data sheet was prepared containing all the results of its physical and mechanical properties obtained on the wood. of the studied species, as well as its resistance classification.
Description
Dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
Madeira abeto de Douglas Módulo de elasticidade Resistência Vigas em escalas reais Densidade Teor de humidade Classe de resistência