Assessment of Dimensional Stability and Bending Strength of Furniture Joints made from Z. gilletii (Okuo) Wood.

Abstract Wood is a hygroscopic and anisotropic material whose dimensional response to environmental conditions presents a major challenge in the performance and durability of wood-based products. Among its physical characteristics, shrinkage and swelling are the most critical, as they significantly influence the serviceability of furniture and structural joints exposed to fluctuating climatic conditions. Dimensional changes occur when the moisture content of wood falls below the fibre saturation point, leading to differential movement along the longitudinal, radial and tangential grain directions. These directional variations often result in internal stresses that may cause joint loosening, surface checking, adhesive bond failure, coating deterioration and eventual structural damage in furniture components. Consequently, the long-term performance of furniture joints is closely associated with the dimensional stability of the wood material used. This study evaluates the shrinkage and swelling behaviour of Z. gilletii and bending performance of two furniture joints, namely the conventional mortise and tenon joint and the modified splayed-mortise-tenon joint made from Z. gilletii. Emphasis is placed on assessing the structural integrity and load-carrying capacity of the splayed mortise and tenon configuration under bending forces. The findings provide insight into the suitability of the splayed mortise joint as a viable alternative to the traditional mortise-and-tenon joint for improved joint strength and dimensional stability in furniture applications.