Low-cycle fatigue analysis of a new type of reduced-beam-section connection

Stress concentrations in a new type of reduced-beam-section (RBS) connection were investigated. Experimental and numerical results of RBS connections with semilunar web (SW) and holed tubular webs (HTW) were compared with connections with tubular webs (TW). For the SW, two semi-circular plates were used in place of a flat web in the beam. For the HTW, a steel tube was used instead of part of the beam web and holes were created in the beam web. For the TW, a steel tube was used instead of part of the beam web but without holes. The connections had adequate shear capacity but made little contribution to flexural stiffness and capacity. Semi-deep beam specimens were fabricated and tested under cyclic loading. The results showed that the beam connections with SWs and HTWs had 30% and 20% less fatigue damage respectively than those with TWs. The story drift capacity was also increased to 7%, much more than that stipulated by current seismic codes. The specimens were modelled using finite-element software to validate the experimental results.