Feasibility Study of Flat Joint Method Using High-Tension Bolt Friction Joints in Light-Gauge Steel Structures and Fundamental Study on Resistant Mechanism

Recently, light-gauge steel structures that can reduce the amount of steel compared to heavy steel structures have attracted more attention. However, there are no detailed guidelines for designing joints in light-gauge steel structures in Japan. To provide the rigid joints in light-gauge steel structures, processing and construction gets complicated, and projections on the flange by jointing with bolts can interfere with the floor slab and finishing materials. In this context, this study proposes the flat joint method, a joint method that has no projections on the flange by frictional bolted jointing at only the beam web and aims to develop a rigid joint without welding. The flat joint method has a frictional steel plate to connect, which transfers stress on the beam to the other one through frictional force. Therefore, the flat joint method follows the mechanical principles of the joint function. A tensile test of the flat beam joint was conducted to reveal the fundamental mechanical properties. It was expected that the flat joint will be a complex stress transfer mechanism for the distribution of cross-sectional stress under bending forces, because of the contact and arrangement of plate and joint elements, and the mechanical relationships due to bearing stress and friction. Additionally, we analyzed findings from this tensile test in detail by using the finite element analysis method. From the results of the tensile test and finite element analysis, evaluation methods for mechanical properties of the flat joint under tensile force were determined.