Experimental investigation of traditional half-lap and mechanically fastened timber connections

The increasing demand for sustainable construction materials has renewed interest in timber due to its renewability, low embodied energy and reduced environmental impact. The safety and integrity of timber structures are strongly dependent on the mechanical efficiency of their connections along with the benefits of the material. Therefore, a thorough understanding of the mechanical properties of timber connections is essential for structural timber design. Traditional timber connections have recently attracted attention as environmentally friendly alternative to mechanically fastened connections; however, their mechanical behaviour remains insufficiently understood. This study experimentally investigates the behaviour of a traditional half-lap connection and compares with four commonly used mechanically fastened timber connections. An experimental program consisting of twelve specimens from five connection configurations is conducted under monotonic and cyclic loading conditions. The behaviour of the connections is comprehensively evaluated in terms of lateral load-carrying capacity, energy dissipation, stiffness degradation and failure mechanisms. The experimental results show that connections with perforated plates and angle brackets exhibited stable and ductile behaviour with improved energy dissipation capacity under both loading protocols. Among all tested connection types, both screwed connection configurations exhibited significantly lower energy dissipation capacity and most rapid stiffness degradation. Furthermore, traditional half-lap connections can achieve competitive performance in terms of load carrying capacity, energy dissipation and ductility when properly detailed.