A Study of Semi­ridged and Non­Linear Behaviour of Nailed Joints in Timber Portal Frames

SYNOPSIS In this paper a study is made of the semi-rigid and non-linear behaviour of nailed knee joints in timber frames. A numerical analysis is applied to the non-linear deformation of the joints. The solution is derived using the stiffness method of analysis in which the rotation of each nailed joint is modelled by a series of piece-wise linear relationships, based on the load-deformation characteristics of nailed joints laterally loaded in single shear. The stiffness matrix is corrected at each step, to allow for joint flexibility; and the short-term non-linear deformation of frames, up to ultimate load, is calculated. Experimental verification is made using knee joint specimens and 6 m span timber portals with nailed plywood knee joints. The test results confirm the applicability of the analysis