Modelling of creep behaviour of timber dowelled beams

Abstract

Extensive researches have been dedicated to study creep in wooden structures where good insight was gained on the phenomenological behaviour. However, long-term creep laws and practical methods to investigate the creep’s influence on safety and serviceability of wood structures during their life-cycle are still very few or don’t exist. This paper investigates the creep of wooden structures using a combined numerical and experimental study. Uni-axial tests (i.e. compression/tensile tests in different directions) were used to calibrate the constitutive law of spruce species and to identify the elastic parameters of the constitutive law. For creep parameters identification, three point bending tests were performed for compressed and uncompressed spruce wood. Subsequently, the results of the three point bending tests were used in conjunction with the numerical model in an inverse problem to obtain the viscous parameters. This technique was adopted for both compressed and uncompressed wood samples. Furthermore, a parametric study was conducted on laminated beams of uncompressed spruce boards assembled by compressed spruce dowels. The behaviour of the whole hybrid structure was studied and several interesting findings were highlighted.