Elastic stiffness of timber joints with dowel-type fasteners and slotted-in steel plate based on the theory of beam on elastic foundation

Abstract

Based on the theory of beam on elastic foundation (BOEF), the exact theoretical solutions for determining the stiffness of single dowel/bolted timber connections with slotted-in steel plate were developed in this work. It aimed at exhibiting clear relations between the connection stiffness and the detailed influence parameters including the timber embedment stiffness, the fastener diameter and the timber member/steel plate thickness. On the basis of the theoretical models, simplified numerical regression equations were proposed for practical application. For validation, a series of parametric tests on the connections were also conducted. It was found that the connection stiffness increases significantly with the increase of the timber embedment stiffness and the fastener diameter, while decreases smoothly as increasing the steel plate thickness. Also, when the timber member thickness is small, the connection stiffness rises prominently with it, but it grows smoothly or even decreasing after the thickness reaches to about five times of the fastener diameter. As the timber member thickness becomes even larger, the connection stiffness will maintain almost constant. The proposed theoretical and numerical methods was proved to be effective for predicting the connection stiffness with the error approximately 30% lower than that determined by the design methods in Eurocode 5.