Experimental testing and theoretical prediction of traditional dowel-type connections in tension parallel to grain

This paper presents theoretical and experimental assessment of full-scale traditional dowel-type connections in tension parallel to grain made of Norway spruce (Picea abies L. Karst.) and English oak (Quercus robur L.). The joint dimensions were derived from the nominal dowel diameter d = {12, 16, 20, 24} mm according to the European standards EN 383 and EN 26891. Determination of the total joints displacement and surface strain distribution on the dowels was carried out using digital image correlation (DIC) technique. The theoretical and experimental approaches were focused on the determination of the load-slip joints moduli (K) and the dowel load-carrying capacity (Py) for various dowel diameters with the same length/diameter ratio equal to 3. The theoretical solution of the load-slip joints stiffness was carried out according to the Beam on Elastic Foundation (BEF) theory and the dowel load-carrying capacity according to Johansen's yield theory based on the European yield model (EYM). The theoretical results correlated with experimental values quite well. The theoretical solution proved to be a proper way for the design of the wooden dowel-type joints from the safety perspectives.