Numerical Investigation of Reinforcement of Timber Elements in Compression Perpendicular to the Grain using Densified Wood Dowels

Abstract

In recent years, the construction industry has seen a greater focus on the use of sustainable construction materials to reduce the environmental impact of buildings. Timber is one such material that has seen a revival in its use due to its environmental credentials coupled with advances in the manufacture of engineered wood products and connection technologies. While timber and engineered wood products have a high strength-to-weight ratio suitable for large scale construction, timber is an orthotropic material and demonstrates poorer strength when loaded perpendicular to the grain. As a result, special consideration must be given to the design of areas of support where stress perpendicular to the grain develops in timber structures. This paper describes a study which examines the use of densified wood dowels as a sustainable reinforcement against perpendicular to the grain stresses using experimental and numerical approaches. Glued laminated timber samples were reinforced with 2, 4 and 6 densified wood dowels. The experimental results show significant improvements in load-bearing capacity can be achieved. A full 3-dimensional solid finite element model has been implemented in ABAQUS/Explicit software. The numerical model utilises cohesive zone modelling (CZM) and Hill plastic yield criterion to predict the failure behaviour of specimens utilising densified wood dowel reinforcement. The examined numerical modelling approach has been shown to give good predictions of the performance of the dowel-timber interaction and load-bearing capacity of the composite system. The numerical model has been also used in a parametric study to examine the influence of dowel diameter and dowel length on the failure behaviour. A maximum dowel length-to-diameter ratio is recommended based on the numerical results