Smooth Hysteretic Model of H‐shaped Steel Beams

ABSTRACTSteel frame structures are generally designed with a beam‐collapse mechanism in mind. Beam members are important earthquake‐resistant elements that dominate the behavior of an entire structure during an earthquake. In order to improve the structural design of such beams, it is important to clarify their performance during cyclic loading, because beams are subjected to a cyclic bending moment under the influence of seismic forces. Hysteretic models have been proposed for each slenderness ratio of lateral buckling for H‐shaped steel beams with lateral buckling. However, this provides inconsistent results and a lack of continuity. Since lateral buckling is a continuous process, it is more reasonable to use a hysteretic model containing continuous parameters.In the present study, we develop a simple smooth hysteretic model that is valid for all lateral buckling slenderness ratios. We applied the that proposed hysteretic model for the reinforced concrete structure to H‐shaped steel beams. In the proposed hysteretic model, which involves an H‐shaped steel simple beam undergoing bending at one‐end, the behavior of the weakened area when the maximum loading capacity has been exceeded can be expressed using two parameters: the lateral buckling slenderness ratio and the standardized width thickness ratio. In addition, we also propose a hysteretic model that can be adapted for a uniformly distributed bending moment and an antisymmetric bending moment. We expect that simple smooth hysteretic model can be applied to a wide range of H‐shaped steel beams.