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Abstract(s)
O conhecimento das características, propriedades e os fatores que influenciam o comportamento físico e mecânico da madeira ajudarão a compreender o comportamento da mesma.
O principal objetivo desta dissertação é conhecer as propriedades físicas e mecânicas de duas espécies de madeira, uma resinosa que é o Pinho e outra folhosa que é o Freixo.
Numa primeira fase pretende-se avaliar a influência do teor de água na estabilidade dimensional da madeira de Pinho e Freixo. Nesta avaliação está integrada a variação da massa e a variação das dimensões no sentido longitudinal e transversal das fibras.
A metodologia utilizada é baseada nas normas portuguesas NP 614 – Determinação do teor de água e NP 615 – Determinação da retração.
Um segundo objetivo desta dissertação consiste na apresentação dos ensaios experimentais de tração no sentido longitudinal e transversal às fibras realizados em provetes de Pinho e Freixo, obtendo-se parâmetros que tentam descrever o seu comportamento mecânico, nomeadamente o módulo de elasticidade, o coeficiente de Poisson e ainda a resistência à tração paralela ao fio.
Estes parâmetros são particularmente relevantes quando se pretende efetuar análises numéricas de estruturas, como é objetivo futuro.
Em outra das fases foi feita a análise numérica realizada para determinar a resistência à tração da madeira de Pinho e Freixo, nas direções ortotrópicas. O modelo de elemento finito foi feito em 3D e foi usada para avaliar a as tensões, deformações e forças.
Por fim foi comparado os resultados obtidos com os ensaios há tração da análise numérica com os ensaios experimentais.
The knowledge of the characteristics, properties and the factors that influence the physical and mechanical behavior of wood help you understand the behavior of wood. The main objective of this work is to understand the physical and mechanical properties of two wood species, which is a resinous pine and other hardwood that is Ash. In the first phase aims to assess the influence of water content on the dimensional stability of wood Pine and Ash. This assessment is integrated with mass variation and the variation of the dimensions in the longitudinal and transverse direction of the fibers. The methodology used is based on Portuguese standards NP 614 - Determination of water content and NP 615 - Determination of shrinkage. A second objective of this work is to present the experimental tensile tests in the longitudinal and transverse direction to the fibers made in Pine and Ash specimens, obtaining parameters that attempt to describe the mechanical behavior, in particular the elastic modulus, Poisson's ratio and also the shear strength to the wire. These parameters are particularly relevant when you want to perform numerical analysis structures. In the last phase of this work was performed a numerical analysis to determine the tensile strength of wood Pine and Ash. The finite element model was done in 3D and was used to evaluate the stresses and deformation forces. Finally the numerical results obtained were compared with experimental tests.
The knowledge of the characteristics, properties and the factors that influence the physical and mechanical behavior of wood help you understand the behavior of wood. The main objective of this work is to understand the physical and mechanical properties of two wood species, which is a resinous pine and other hardwood that is Ash. In the first phase aims to assess the influence of water content on the dimensional stability of wood Pine and Ash. This assessment is integrated with mass variation and the variation of the dimensions in the longitudinal and transverse direction of the fibers. The methodology used is based on Portuguese standards NP 614 - Determination of water content and NP 615 - Determination of shrinkage. A second objective of this work is to present the experimental tensile tests in the longitudinal and transverse direction to the fibers made in Pine and Ash specimens, obtaining parameters that attempt to describe the mechanical behavior, in particular the elastic modulus, Poisson's ratio and also the shear strength to the wire. These parameters are particularly relevant when you want to perform numerical analysis structures. In the last phase of this work was performed a numerical analysis to determine the tensile strength of wood Pine and Ash. The finite element model was done in 3D and was used to evaluate the stresses and deformation forces. Finally the numerical results obtained were compared with experimental tests.
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Keywords
Madeira Pinho Freixo Variação dimensional Tração