79 WOOD RESEARCH 54 (3): 2009 79-88 THE BENDING MOMENT CAPACITIES OF MITRE FRAME CORNER JOINTS WITH DOVETAIL FITTINGS Murat Kılıç Republic of Turkey Ministry of environment and forestry, Central Anatolia Forestry Research Institute, Ankara, Turkey Erol Burdurlu Gazi University, Faculty of Technical Education, Department of Furniture and Decoration, Ankara, Turkey Suat Altun KarabükUniversity, Faculty of Technical Education, Department of Furniture and Decoration, Karabük, Turkey Umut Özgür Berker Hacettepe University, School of Vocational Technology, Wood Products Industrial Engineering, Ankara, Turkey ABSTRACT In this study, the bending moment capacities under the diagonal compression and tensile loadings of the mitre frame corner joints with dovetail fttings were investigated. Solid poplar wood (Populus nigra) was used in the production of framework pieces. Recently, mitre frame corner joints with dovetail ftting are preferred in practice. Tis has been infuential in the making of this study. A total of 80 each mitre frame corner joint specimens with dovetail ftting were prepared for this purpose. Of these, 20 were prepared with polyvinyl acetate (PVAC) adhesive, 20 were prepared with polyurethane (PU) adhesive, 20 were prepared with cyanoacrylate (CA) adhesive and 20 were prepared without adhesive (WA). Solid poplar wood (Populus nigra) was used as a frame material. Te specimens were subjected to diagonal tensile and compression processes in the universal test machine in accordance with ASTM-D 143-94. Te data obtained at the end of the tests were analyzed statistically and the results were evaluated. According to this, the highest bending moment capacity under the diagonal compression loading (MC-L) (55.71 N · m) and bending moment capacity under the diagonal tensile loading (MC-T) (160.55 N · m) was obtained in the specimens bonded with PVAC adhesive. Whereas, the lowest MC-L (18.45 N · m) and MC-T (14.06 N · m) was obtained in the specimens without adhesive (WA). Te diference between the MC- T and the MC-Cof the specimens bonded with the CA and PU adhesives was insignifcant. Accordingly, it is defnitely necessary to use adhesives in the bonding of dovetail fttings for obtaining a higher MC-T and MC-C. Te best result among the available adhesives was obtained with the PVAC adhesive. KEY WORDS : adhesives for wood; tensile strengths; compression strengths; mitre frame corner joints.