Fatigue Reduction in Tubular Web Connections in Semi-deep Beams

Abstract

In this paper, the experimental and numerical results of a new type of Reduced Beam Section (RBS) connection called (abbreviated of Holed Tubular Web), are investigated. The HTW-RBS connection is a kind of accordion-web RBS connection by which contribution of the web to the flexural capacity of the beam would be reduced. In HTW-RBS connection, a steel tube is used instead of part of the beam web to place the plastic hinge in the expected location and also holes are created on the beam web. Similar to the corrugated webs, HTW-RBS connection has also adequate shear capacity but has little contribution to the flexural stiffness and capacity. Specimens of semi-deep beams with HTW-RBS connections are prepared and tested under cyclic loading. Results of proposed connection (HTW-RBS), indicated that the fatigue caused by stress concentration at the connection of the tube and beam is decreased and no fracture and cracking occurred at this area. Holes as second fuse actuated After the tube (primary fuse) and the length of plastic hinge is increased. Specimens provide at least 7% story drift, without any significant strength loss, which is more than current requirements for qualifying connections in special moment frames. Finally, the HTW-RBS specimen is simulated by finite element software and the results are compatible with the experimental results.