Predicting capacity and stiffness of glued-in Glass Fiber Reinforced Polymer rods in heritage timber frames

Conservation and repair of historic timber structures are large topics since many parameters such as static scheme of the structure, importance and location of the decay, implementation of the repair, must be taken into account when making recommendations for interventions. Glued-in rod connections are widely used as repairs in timber structures. Since stiffness of connections has a large influence on the static scheme of a timber structure - and therefore on the distribution of stresses within it- , predicting stiffness of glued-in rods interventions can avoid damaging changes in those structures, which could lead to the collapse of the whole structure. A finite element model based on cohesive surface is thus developed to predict the behaviour of glued-in Glass Fiber Reinforced Polymer (GFRP) rods set parallel to the grain and axially loaded. Experimental results from previous investigations are used to first calibrate and then validate the model. A parametric study regarding the cohesive surface is also undertaken and discussed.