Influence of bondline brittleness and defects on the strength of timber finger-joints

Numerical finite element results on the mechanical behaviour of finger-joints for laminated timber products are presented. Simulations are based on a nonlinear fracture mechanics description of the bondlines in the finger-joints. It is shown that, for a commonly used resorcinol–phenol adhesive, there is potential of increasing substantially the finger-joint strength by increasing the fracture energy of the bond. However, even a single, small glueline void can have a considerable influence on reducing the joint strength.