Advances in the knowledge of the influence of moisture changes on the long-term mechanical performance of timber structures

The paper reviews some advances in the understanding and modelling of the effects of moisture conditions and moisture changes on the long-term performance of structural timber. Particularly it describes recent progress in constitutive modelling of the moisture change dependent creep, the mechano-sorptive effect, and in the understanding of the strength reduction of timber structures due to simultaneous load and moisture changes, the ‘mechano-sorptive duration-of-load effect’. The importance to analyse the effect of natural humidity changes on stress and strain state is emphasised.RésuméCet article passe en revue les progrès accomplis dans la compréhension et la modélisation de l'impact des conditions d'humidité et de leurs modifications sur les performances à long terme des constructions en bois. Sont plus spécifiquement analysées les récentes avancées en matière de modélisation constitutive du fluage lié aux changements d'humidité, les effets mécano-sorptifs, et dans la compréhension de la diminution de la résistance des structures en bois en raison des modifications simultanées du chargement et de l'humidité (l'effet ‘mécano-sorptif de la durée de chargement’). Ce papier met l'accent sur l'importance de l'analyse des effets des modifications naturelles de l'humidité sur le diagramme contrainte-déformation.

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