Long-term creep behavior of timber columns: Experimental and numerical protocols

Abstract

This work deals with an experimental and numerical approach to determining the differed behavior of compressed wood elements subjected to creep loading. An experimental protocol is associated with a mechanical model, whose purpose is to isolate the effects of creep from those of shrinkage-swelling, while allowing for a long duration test to be conducted. The experimental protocol is based on a compression creep test applied to five wooden columns disposed in a climatic room for one year. The numerical model is based on the use of a Kelvin-Voigt rheological model associated with a shrinkage-swelling element. An optimization study is proposed in order to interpolate the model parameters with respect to the experimental measurements. In the context of a linear viscoelastic behavior, the result of this interpolation allows to propose a model extrapolation for long times. Within the framework of the European code, Eurocode 5, this project aims to identify the long-term creep coefficient (kdef) adapted to compressed elements, in addition to evaluating the partial creep coefficients as a function of loading duration class.