Dowel Laminated Timber Elements Manufactured using Compressed Wood Dowels

In recent years, there has been an increased focus on the environmental impacts of construction and a movement towards more sustainable construction products. The use of timber as a structural material has grown and it has been deemed to be one of the leading materials of choice in the future as a sustainable construction product that not only has a low carbon footprint but also acts as a carbon store for the lifetime of the structural component. To further improve the environmental performance of timber construction, it is beneficial to reduce the use of adhesives, particularly when manufacturing laminated engineered wood products. This study numerically investigates the structural behaviour of dowel laminated timber (DLT) elements which are laminated with compressed wood dowels instead of adhesives. A parametric study is carried out to examine the influence of dowel diameter and spacing on the stiffness and maximum load capacity of the DLT members. The numerical model incorporates orthotropic, linear elastic materials in tension and linear elastic-plastic materials in compression. Furthermore, damage initiation criteria in the respective material directions are utilised to determine the failure behaviour of the structural elements. The results show that the dowel diameter and spacing have a significant influence on the maximum load capacity and stiffness of the DLT members. The predicted failure behaviour of the numerical model comprises a combination of dowel bending, dowel-timber embedment and tensile fracture of the bottom tensile laminate. The numerical model will allow for an optimised dowel arrangement to be manufactured and experimentally tested.