EFFECT OF MATERIAL, ADHESIVE AND LOADING ON THE STIFFNESS OF WOODEN DOWEL JOINTS

The objective of this study was to evaluate the effects of selected parameters, such as type of loading (compression and tension), the wooden dowel species, and the adhesives type on the joint stiffness. Beech, oak, and Scots pine woods were used as wooden dowel material, and polyvinylacetate (PVAc) and polyurethane (PUR) adhesives were used as adhesive agents. Elastic stiffness on diagonal tension and compression tests were applied on 120 pieces of test samples prepared. The results showed that there was found out that the highest average elastic stiffness value of 656 Nm/rad was achieved in the oak dowel joints bonded with PVAc adhesive under compression loading. The lowest average value of 293 Nm/rad was found in the Scots pine dowel joints subjected to compression stress using PUR adhesive. On average, the elastic stiffness of the oak dowel joints bonded with PVAc adhesive was 17% higher than the elastic stiffness of the Scots pine dowel joints bonded with PUR adhesive. The influence of the wooden dowel species and the adhesive type were found statistically significant.