Bending moment capacity of rectangular mortise and tenon furniture joints

This study investigated the effects of wood species, adhesive type, rail width, tenon depth, and tenon length on bending strength and flexibility of mortise and tenon T-type end to side grain joints. Sugar maple, red oak, walnut, and tulip poplar were utilized in constructing the joint specimens. Specimens were assembled with four types of adhesives. Nineteen groups of mortise and tenon joints with five replications each were tested in bending. Results of the tests indicated that a mortise and tenon joint becomes stiffer as either tenon length or tenon depth is increased. The results also indicate that tenon depth has a more significant effect on joint flexibility than tenon length. Furthermore, the presence of shoulder on the rail member of a mortise and tenon joint substantially contributes to the stiffness of the joint. An empirically derived expression was developed to predict average ultimate bending moment capacity. Semi-rigid connection factors were also determined.