Encontrados 18 documentos, a visualizar página 1 de 2
Reliability analysis of a timber truss system subjected to decay
Brites, Ricardo D.; Neves, L. C.; Machado, J. S.; Lourenço, Paulo B.; Sousa, Hélder S.Assessing the safety of existing timber structures is of paramount importance for taking reliable decisions on repair actions and their extent. The results obtained through semi-probabilistic methods are unrealistic, as the partial safety factors present in codes are calibrated considering the uncertainty exhibited by new structures. In order to overcome these limitations, and also to include the e ects of deca...
A semi-destructive tension method for evaluating the strength and stiffness of ...
Brites, Ricardo D.; Lourenço, Paulo B.; Machado, J. S.The paper presents a new semi destructive method for obtaining a prediction of the tension parallel to the grain properties of clear wood of structural timber members. This method is less intrusive than other existing methods and consists in extracting four small specimens along the length of the timber members. The tension strength and stiffness obtained is intended to be used as input data for the assessment ...
Assessment of the structural properties of timber members in situ : a probabili...
Machado, J. S.; Lourenço, Paulo B.; Palma, PedroThe assessment of the structural performance of existing timber structures is dependent, among other factors, on the capacity to evaluate the physical and mechanical properties of structural timber elements in situ. This paper discusses the possibilities/advantages of using a probabilistic approach to obtain a more reliable prediction of the reference properties of these timber members in situ. The presented ap...
Assessment of the structural properties of timber members in situ : a probabili...
Machado, J. S.; Lourenço, Paulo B.; Palma, PedroThe assessment of the structural performance of existing timber structures is dependent, among other factors, on the capacity to evaluate the physical and mechanical properties of structural timber elements in situ. This paper discusses the possibilities/advantages of using a probabilistic approach to obtain a more reliable prediction of the reference properties of these timber members in situ. The presented ap...
Avaliação das propriedades mecânicas da madeira in situ por ensaios em mesoprov...
Brites, Ricardo D.; Machado, J. S.; Lourenço, Paulo B.Uma das principais dificuldades da avaliação do estado de segurança de estruturas de madeira existentes é a determinação das propriedades mecânicas a utilizar para efeitos de cálculo. Os procedimentos habituais de estabelecimento das propriedades mecânicas com base no estabelecimento de classes de resistência por avaliação visual validada com ensaios não-destrutivos conduzem a resultados muito conservativos. No...
Capacity of a traditional timber mortise and tenon joint
Feio, A. O.; Lourenço, Paulo B.; Machado, J. S.The safety and quality of traditional timber structures mostly depends on the conditions of their connections. A testing campaign has investigated the behaviour of mortise and tenon timber joint. The present paper addresses the quantification of the strength capacity of wood-wood mortise and tenon joint by physical testing of full-scale specimens. In addition, the performance of different non-destructive techni...
Avaliação da segurança de cobertura tradicional de madeira sujeita a degradação...
Brites, Ricardo D.; Neves, L. C.; Machado, J. S.; Lourenço, Paulo B.O presente trabalho propõe-se apresentar a modelação probabilística de uma estrutura-tipo de uma cobertura tradicional de madeira, sendo tomadas como variáveis aleatórias as dimensões geométricas das secções transversais, as propriedades mecânicas da madeira e as acções aplicadas à estrutura, dando especial ênfase ao vento e neve. Depois de estabelecido o índice de fiabilidade β para uma situação de não degrada...
Chestnut wood in compression perpendicular to the grain : non-destructive corre...
Lourenço, Paulo B.; Feio, A. O.; Machado, J. S.This paper addresses the evaluation of the compressive properties of chestnut wood under compression perpendicular to the grain, using destructive and non-destructive methods. Three non-destructive methods (ultrasonic testing, Resistograph and Pilodyn) are proposed and the possibility of their application is discussed based on the application of simple linear regression models. Timber specimens were tested up t...
Non-destructive evaluation of the mechanical behaviour of chestnut wood in tens...
Feio, A. O.; Lourenço, Paulo B.; Machado, J. S.The paper addresses the evaluation of strength and stiffness of chestnut wood, in tension and compression parallel to the grain, using different non-destructive techniques (ultrasounds, Resistograph and Pilodyn). Around two hundred timber specimens (divided into compression and tension tests) were tested up to failure, comprising recently sawn timber (which is now available on the market for structural purposes...
Utilização potencial do lenho de Acacia melanoxylon a crescer em povoamentos pu...
Santos, A.; Teixeira, A.; Anjos, O.; Simões, R.; Nunes, L.; Machado, J.S.; Tavares, M.A Acacia melanoxylon R. Br. (acácia-austrália ou austrália) cresce bem em Portugal, em povoamentos puros ou mistos com Pinus pinaster Aiton, ainda que apresente fortes constrangimentos ecológicos e legais. Apesar de algumas dificuldades, por exemplo na secagem, a madeira de austrália é usada em mobiliário e produtos manufacturados devido, principalmente, à sua textura e cor escura. Pode também ser usada para p...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||