EFFECT OF TENON GEOMETRY, GRAIN ORIENTATION, AND SHOULDER ON BENDING MOMENT CAPACITY AND MOMENT ROTATION CHARACTERISTICS OF MORTISE AND TENON JOINTS

Abstract

Bending moment capacity and moment rotation characteristics of mortise and tenon joints as a function of tenon geometry, grain orientation, length, and shoulder fit were examined. Bending moment capacity of all joints in which tenons were fully inserted in mortises was 54% greater than for joints in which tenons were not fully inserted. Joints with 25.4-mm-long diamond-shaped tenons had greater moment capacity than either rectangular or round tenon joints, whereas joints with 38- or 51-mm-long rectangular tenons had greater capacities than joints with diamond or round tenons. Similarly, for joints in which tenons were not fully inserted, rectangular tenons had the greatest moment capacity regardless of grain orientation or length.