Bending moment resistance of dowel corner joints in case-type furniture under diagonal compression load
We investigated bending moment resistance under diagonal compression load of corner doweled joints with plywood members. Joint members were made of 11-ply hardwood plywood of 19 mm thickness. Dowels were fabricated 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 variables in our experiment. By increasing the connector’s diameter from 6 to 8 mm, the bending moment resistance under diagonal compressive load was increased, while it decreased when the diameter was increased from 8 to 10 mm. The bending moment resistance under diagonal compressive load was increased by increasing the dowel’s depth of penetration. Joints made with dowels of Beech had higher resistance than dowels of Hornbeam. Highest resisting moment (45.18 N·m) was recorded for joints assembled with 8 mm Beech dowels penetrating 17 mm into joint members Lowest resisting moment (13.35 N·m) was recorded for joints assembled with 6 mm Hornbeam dowels and penetrating 9 mm into joint members.
OPTIMISATION OF END TO EDGE BUTT JOINT WITH RESPONSE SURFACE METHODOLOGY: A PRELIMINARY STUDY
One of the most used joints in the construction of furniture is the end to edge butt joint. This type of joint is preferred for the easy of their processing. The effect of heat treatment on the compressive and tensile strength of end to edge butt joint is analysed in this work. Also, it is analysed the optimal dowel length, the distance between dowels and the ratio of dowel penetration in the main part of an end to edge butt joint. The joints were prepared from heat-treated ash (Fraxinus excelsior) wood. The length of dowel has a bigger influence on compressive and tensile strength of joints than the distance between dowels and the ratio of dowel penetration in the main part of joint. An optimal solution to place the dowels is suggested for the joints made of heat-treated wood. The solution implies to have a distance between dowels of 32 mm; a ratio of dowel penetration in the main part of 0,55 and a dowel length of 60 mm.
Bending Strength of Screwed Corner Joints with Different Materials
Tests were carried out in order to determine the bending strength with compression and tension force with and without glue in addition to screws on furniture corner joints in a construction case. The specimens were prepared with particleboard and medium density fiberboard (MDF) surfaced with a synthetic resin sheet. In the connection, two types of screws which have dimensions of 4/50 mm and 5/60 mm were used. For the glued joints, polyurethane Desmodur-VTKA adhesive was used. As a result of these tests it has been determined that the joints with glue are better than the ones without glue and the strength of fiberboard is better than particleboard. Keywords: Bending strength, compression test, tension test, particleboard, wood testing, screws.