Effects of cross-sectional shape on the bending strength in furniture joints

Abstract

Aim of the study: Tests were carried out to evaluate the ultimate bending strength of the circular and square cross sectioned furniture joint members and find out whether the form factor is applicable to the small specimens as they are applied to large specimens and compare the maximum bending strength and specific gravity values of these wood species to those that are specified in reference books. Material and methods: The specimens were prepared from Red oak (Quercus rubra), Yellow poplar (Liriodendron tulipifera), Southern pine (Pinus sp.), Caobilla (Carapa guianensis), and Gmelina (Gmelina arborea). Based on five wood species by five replications, 25 square cross sectional (25 x 25 mm) specimens and 25 specimens which included 19 mm diameter circular mortise and tenon joints, a total of 50 specimens were prepared and tested under the static bending test according to related standards Main results: Results gave the primary indication that the form factor of 1.18 from square to circular cross section is applicable to small clear specimens; however, it should be noted that absolute conclusions require studies in much wider spectrum. Research highlights: The results of this study indicate that designers and furniture engineers may obtain good estimates from 1.18 form factor and comparison of MOR values and specific gravity of the wood species with the book values.