Review of design approaches and test results on brittle failure modes of connections loaded at an angle to the grain

Connections in timber beams loaded perpendicular to grain are prone to brittle failure due to fracture induced by tension perpendicular to grain stresses in the surrounding timber. Different approaches can be found in literature and design codes to account for the reduction of load-carrying capacity in the design of the structure. In this study selected design approaches are discussed and their behaviour with regard to different geometrical parameters is analysed. The structural behaviour of connections loaded perpendicular to grain is evaluated on the basis of test results from literature. The impact of different geometrical parameters on the load-carrying capacity is demonstrated and the design approaches are benchmarked against a large number of individual test results.
Recommendations for a more reliable design are given.