Structural behavior of timber-steel-joints with either dowel-type fasteners or continuous joints

For the development of a new hybrid construction method combining the materials steel and timber for linear load-carrying elements subjected to bending loads, different joining methods were investigated. The joining methods were 1) dowel-type fasteners, partly in combination with higher friction in the shear plane and 2) continuous joints, mainly by bonding with adhesives. Tests were carried out to investigate the maximum load-carrying capacity as well as the stiffness of the joints, aiming to transfer the results to the linear load-carrying elements. Where applicable, nominal shear stresses were evaluated. The tests with dowel-type fasteners were mainly carried out to create reference values to compare to the other joining methods. The results with the modified surfaces to increase friction in the shear plane were quite promising regarding the initial stiffness, however, further research of the surface modification has to be carried out. The specimens with continuous joints can be regarded analytically as fully bonded. Bonded specimens with additional bolts combine high stiffness with a residual load-carrying capacity after shear failure of the timber of 30-40% of the maximum load.