Behaviour of timber connections using glued-in GFRP rods under fatigue loading. Part I: In-line beam to beam connections

Glued-in rods are an attractive option for making connections in timber structures. This paper describes the static and fatigue behaviour of in-line beam to beam connections made using glass fibre-reinforced plastic (GFRP), pultruded rods bonded into the end grain of LVL beams with epoxy resin. The beam to beam samples were connected with three rod configurations and the mechanical performance of these in-line jointed beams was compared with solid unjointed LVL. The mode of fatigue loading selected was flexure in compression–compression at R = +10. The results show that solid LVL beams have significantly higher static and fatigue strengths than beams jointed using GFRP glued-in rods, but the capacity of solid LVL to dissipate energy under cyclic loading is much less than for the jointed beams. The pattern in the development of the shape of hysteresis loops for beams in fatigue is, in general, an increase in loop area and decline in dynamic modulus with increasing number of cycles.