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International audienceThe mechanical and physical properties of wood structural elements and of wood structures are strongly affected by the combination of humidity, temperature variation and biological attack. The aim of this study is to develop a design model able to estimate timber elements decay function of the exploitation climatic conditions (temperature and humidity). The deterioration program may be applied on any type of wood element and is indicating the necessity of increasing the cross section dimensions if and when the specific humidity and temperature become of significant influence. The results of this study are of great importance as the behavior of a non-treated timber element can be surveyed when directly influenced by changes in climatic conditions (relative humidity and temperature)

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Cracking initiation and propagation are frequently recognized as main causes leading to failure of timber structures. Since the kinematics of both processes is largely influenced by environmental conditions, a comprehensive reliability assessment of notched structures should take into account such environmental factors. The main purpose of this paper is to propose a methodology for reliability assessment and updating of notched timber components based on mechanical (A-integral formulation) and reliability (simulation and Bayesian networks) methods, and experimental data. The A-integral formulation is used to estimate energy release rates in modes I and II by taking into account thermal effects; but its numerical implementation is time-consuming for uncertainty propagation. In order to deal with this problem, Bayesian networks were used for reliability assessment and updating. The experimental data used for updating purposes were obtained from measurements of deflection, temperature and relative humidity on a notched beam (Douglas Fir specie) exposed to outdoor environment and constant loading. The whole proposed methodology was illustrated with the reliability assessment and updating of the studied notched beam. The results indicated that the proposed approach is able to integrate measurements of temperature and deflection for reliability updating.