Experimental investigations on the load-bearing behaviour of traditional and newly developed step joints for timber structures.

• Improved load-bearing behaviour of newly developed step joints for timber structures. • Relation between onset of failure and ultimate load depends on geometry of carpentry joints. • Experimental determined data on the load-bearing behaviour for timber joints are provided. • Gluing in combination with screw clamps leads directly into a linear elastic load-bearing behaviour. • Failure mode of step joints depends on the geometry. In this paper the load-bearing behaviour of traditional and newly developed timber-timber connections, multi-step and free formed, are analysed within an extensive investigation focusing on joint failure. DIC measurements allowed for an assessment of the initial behaviour of the systems and their specific failure modes. By comparing the stiffness and various load levels to those of typical joint designs the improved load-bearing behaviour of the proposed joints was demonstrated while defining the range of the obtained linear-elastic phase. The results show that the onset of failure, based on the ultimate load, strongly depends on the geometry of the joint. [ABSTRACT FROM AUTHOR]