Mechanical behavior of bolted steel laminated bamboo lumber connections loaded perpendicular to grain

Laminated bamboo lumber (LBL) is increasingly used in structural applications for its superior mechanical properties. Connections always play a significant role in structural application and this paper presents test results on the mechanical behavior of typical bolted connections in LBL that are often subjected to loading in perpendicular to the grain direction. This paper presents a pilot test program to provide useful experimental evidence of the behavior of bolted connections in LBL. 45 specimens in 9 groups were considered in the current study to investigate the effects of LBL thickness, the edge distance of the joint and the failure characteristics when loading was applied perpendicular to the grain. Obtained results showed that the connections predominantly underwent splitting failure perpendicular to grain and was brittle in nature. The edge distance showed pronounced effect on the ultimate capacity of connections compared to the thickness. Typical splitting failure of LBL under the current loading conditions showed mixed mode fractures i.e., combination type I and II fracture modes. Existing analytical techniques for timber were used to predict the observed connection capacities but they all produced significantly conservative results. A semi-empirical formula based on Vander Put model has been proposed to capture the behavior of LBL bolted connections under perpendicular to the grain loading.