Elastic deformation analysis of rotational wood-dowel welding joint system based on the variational method

This study aimed to investigate the elastic deformation of rotational wood-dowel welding joints by using the variational method, as there was no efficient tool to access the deformation behavior of welding joints perpendicular to axis orientation so far. Based on the variational method, the displacement control equation of axially-loaded dowel-welded wood joints was derived. By incorporating the boundary conditions and using an iterative approach, the parameters required in the control equation were determined. The analytical expression ϕ(r) for the deformation function of the wood substrate under elastic conditions was proposed, thereby determining the displacement and axial force of the single wood-dowel. The elasticity modulus was the primary influence parameter on the function ϕ(r). However, the welding depth had a more critical impact, and reasonable combination of parameters could lead to a better interaction between the wood dowel and substrate. The comparison between calculated results and test trials collected from the previous studies indicated that the elastic solution method could accurately estimate the pull-out ultimate bearing capacity and deformation characteristics of the welding joints. This work can provide unique perspective to understand the technology of rotational wood-dowel welding joints, and a good reference suggestion for the manufacture of multi-dowel welding joints.