Modelling of Finger-Joint Failure in Glued: Laminated Timber Beams

This paper presents a novel approach to the modelling of failure
of finger-joints in glued-laminated beams. A nonlinear strain-softening model
with stochastic material parameters was used to characterise the failure zone
of the finger-joint. Monte Carlo simulations of the behaviour of finger-jointed
laminations and of laminated beams were performed using the finite element
method. Various lamination thicknesses and beam depths were investigated,
as well as the effect of varying the ductility of the finger-joint. Finally the use
of simplified finger-joint material models was also investigated. The results
show that the proposed approach can account for such phenomena as the size
effect and the laminating effect. Another observation is that the finger-joint
ductility has a major influence on the lamination and beam strength and that
a special case of the present modelling approach can be made to coincide with
the classic weakest link theory of Weibull.