THE BENDING MOMENT RESISTANCE OF SINGLE-DOWEL CORNER JOINTS IN CASE CONSTRUCTION

This study was carried out to obtain background information concerning the bending moment resistance of single-pin dowel joints in particleb oard and also to provide the background information needed to formulat e expressions for predicting the bending moment resistance of single-d owel, L-type, corner joints in particleboard. Test results indicated t hat the bending moment resistance of the single-dowel corner joints in creased significantly as dowel diameter increased from 1/4 to 3/8 inch and as the depth of dowel embedment in the face member increased from 1/4 to 5/8 inch. Changes in depth of embedment in the edge member fro m 3/4 to 1-1/2 inches, however, had no effect on bending moment resist ance. Single-dowel comer joints loaded in tension had slightly higher ultimate bending moment resistances than the joints loaded in compress ion. In the compression tests, the dowel withdrew from the edge member in a few cases when the depth of dowels in the edge member was 3/4 in ch. In the tension tests, the edge member split when the depth was 3/4 inch. In order to obtain the maximum bending moment resistance, there fore, a conservative embedment depth of 1 inch is suggested as an opti mal value for dowel embedment in the edge member. In general, the bend ing moment resistance of the joints in compression could be predicted by means of the expression: Y(c) = 460.4 x (D)0.452 x (E)1.140 and in tension by means of the expression: Y(t) = 614.6 x (D)0.591 X (E)1.180 where: Y = the bending moment resistance of the single-dowel joint in particleboard (lb.-in.) D = the dowel diameter (in.) E = the depth of dowel embedment in the face member (in.)