Investigation of shear resistance of glued scots pine joints with 3D printed dowels manufatured from different materials

In this thesis study, the shear resistances of the joints constructed by gluing straight spiral and grooved patterned dowels produced using PLA, tough PLA, PA and tough resin materials with 3D printers and gluing them to Scots pine surface-edge joints were measured. Results indicated that the highest shear resistance value was given by the joints produced from straight patterned dowels produced from tough resin with an average value of 2845 N. This was followed by the shear resistance values of grooved patterned dowels with 2819 N and spiral patterned tough resin dowels with 2725 N. The shear performances of the Scots pine joints produced from tough resin dowels were followed by the shear performances of the joints with different patterns produced from tough PLA, PLA and PA, respectively. There is no statistical difference in the shear resistance of the joints produced from dowels produced with different patterns in general. Here, the shear performances of the joints with grooved and straight patterned dowels made of PA were statistically higher than the joints with spiral patterned dowels. On the other hand, the shear performance of the joints with tough resin dowels was higher than the shear performance of the dowels produced with solid wood and PA molding methods also used in the market. When the failure modes of the joints were observed, it was observed that in the joints with dowels made of tough materials, rupture at the glue line and rupture of the Scots pine wood material near the upper edge of the dowel, while the fracture modes of the joints with dowels made of PA and PLA were only rupture of the Scots pine samples from the glue line.