Study on the Effects of Selected Factors on the Diagonal Tensile Strength of Oblique Corner Furniture Joints Constructed by Wood Dowel

Abstract

The oblique corner joints (OCJ) of wood-frame furniture doors crack easily during common usage due to external loads or changes in temperature and humidity. Aiming to solve this technology issue, the effects of the selected factors, i.e., material type (MT), diameter of dowel hole (DDH), moisture content of dowel (MCD), and distance between two dowels (DTD), on the diagonal tensile strength of the oblique corner joint (OCJ), were investigated experimentally and optimized based on the response surface method. The results showed that there were two typical mechanical behaviors of OCJs when subjected to diagonal tensile loads, according to load and displacement curves and failure modes. The critical crack strength, Fc, and ultimate strength, Fu, of samples made of heat-treated alder were smaller than those of samples made of control alder. DDH had a significant effect on Fc but not on Fu, while the effect of DTD on both Fc and Fu was significant. The Fc defined in this study was a better indicator for evaluating the crack load resistance of OCJs than Fu. The OCJs constructed by double dowels were significantly greater than those of single dowels. The optimal parameters for constructing the OCJs were obtained: MT was the control wood material, DDH was 7.8 mm, double dowels with a DTD of 27 mm, and the MCD should be higher than that of the base material.