Large diameter fastener in locally reinforced and non-reinforced timber loaded perpendicular to grain

• Joint with mechanical fastener 49.0 mm in diameter was researched.
• The research was done on locally reinforced and non-reinforced timber elements.
• UMAT subroutine and cohesive interaction was used for modelling wood properties.
• Joint reinforcement increases strength, ductility and splitting capacity of joint.
• Equation for reinforced joint splitting capacity has been proposed.

The research deals with a 49.0 mm in diameter mechanical fastener to which load perpendicular to grain is applied. The experimental research was divided in two series: the first series was carried out with locally reinforced, and the second with non-reinforced timber specimens. The local reinforcement of timber elements with textile sheets between lamellas in a layer of adhesive was made in the production process. Furthermore, research on finite element models using Abaqus/CEA software package was carried out. UMAT subroutine and cohesive contact between surfaces were used for modelling complex timber mechanical properties and cracks opening. The research results have shown that glass fiber textile placed between lamellas in adhesive layer effectively increases the resistance and splitting capacity of timber joint. Analytical approach has been proposed for predicting the splitting capacity of the reinforced joint.