Establishing mathematical model withdrawal resistance of wooden dowel in plywood

The goal of this study was to investigate withdrawal resistance of doweled joint with plywood members and establishing a predicting mathematical model for such joints in which regularly dowel is installed perpendicular to surface and also edge of plywood. Joint members were out of 11-ply hardwood plywood (Hornbeam، Beech and Alder) that were 19 mm in thickness. Dowels were fabricated out of Beech and Hornbeam species. Their diameters (6، 8 and 10 mm) and depths of penetration (9، 13 and 17 mm) in joint members were chosen variable in this experiment. Results have shown that withdrawal resistance of doweled joints made on face and edge of plywood members، increases with increase of dowel’s diameter and its penetration depth. Joints made with dowels of Hornbeam had higher than dowels of Beech ones. Highest withdrawal resistances (2951 N، 2441 N) were observed in joint on face and edge side of plywood members made with dowels of Hornbeam which were 10 mm in diameter and their depth of penetration was 17 mm. Lowest withdrawal resistance values (799 N، 784N) were of Beech wood dowels which were 6 mm in diameter and 9 mm penetrated into members.