Computational modelling of mechanical response of glulam beams due to moisture inducted delamination

Abstract

Glued laminated timber beams are nowadays used as load-bearing beams of large-span structures that operate in various humidity conditions. Typical application areas are aqua parks with high humidity as well as market halls with low humidity. It is related to the possibility of the occurrence of cracks typical for the drying of wood, even with such controlled conditions of production technology as glued laminated timber. Cracks visible on the used girders raise doubts as to the safe operation of the structures. The subject of this paper is the computational simulation and the evaluation of the influence of beam delamination on the mechanical response of the structure. The attention was established on a typical two-span beam of constant height with a slight slope to the horizontal. The numerical analysis was carried out for three variants of the location of potential delamination of different scope. The beams were modeled as a problem of the linear theory of elasticity in a plane stress state with orthotropic material properties. The calculations were made in the Abaqus software environment. The results obtained in the paper allow to determine the areas in which the presence of delamination or cracks should be considered dangerous from the point of view of the safety of operation. Computational analysis is helpful in assessing the safety of structures where cracks appear. Theoretical considerations are supplemented by an example from engineering practice.