Determination of the strength performance of chair frames constructed of solid wood and wood composites

In this study, the strength properties of glued-doweled and screw jointed chair frames constructed of solid wood and wood-based (composite) materials were investigated. Scotch pine (Pinus Syivestris Lipsky) and Turkish beech (Fagus Orientalis Lipsky) were used as solid wood materials. Oriented strandboard (OSB), okoume (Aucoumea klaineana) plywood (PLY) and medium density fiberboard (MDF) were used as wood composites. Specimens were tested under static load according to the principles of ISO/DIS 7174/1 (ISO 1988) by applying both seat and backrest loads, which can be imposed upon the chair in service. In addition, specimens were structurally analyzed via the finite element method (FEM). The results show that three-dimensional (3-D) structural analyses by means of FEM gives reasonable estimates of the overall strength performance of the chair frames. As a result of static tests, it was concluded that the wood composite materials could be used as an alternative to solid wood material. In addition, portable connection techniques provide many advantages for designers, producers, sellers, and users. Performance testing was proven to be an essential part of the design process. These tests allow discovery and observation of unexpected failures and provide useful insight into actual usage and failure conditions.