Development of mathematical model for cyclic behaviour of blind bolted HSS column components

This paper presents an experimental and finite element analysis based mathematical modelling of cyclic behaviour of the component of hollow structural section (HSS) columns under bolt tensile loads. This component acts as an important constituent part to the blind bolted connections with HSS columns. Two typical failure modes and their related hysteretic curves are examined experimentally. It is shown that force versus displacement curves under monotonic loading can be regarded as the upper bound of the envelope of the counterpart cyclic response. Moreover, the hysteretic force-displacement curves of test columns with relatively thick tube walls demonstrate significant pinching manner thus less energy dissipative capacity. Based on the calibrated finite element model, the flexibility of tube wall and its influences on the connection response are compared for two failure modes. Parametric analyses are also performed to investigate the influence of geometric parameters on the elastic stiffness and yield strength. The mathematical hysteretic models allowing for the behaviour of the connections in two typical failure modes are proposed that distinguishes the developed model from those reported in the literature. It is demonstrated that the proposed model incorporating degradations of stiffness and/or energy dissipation can achieve a good representation of test hysteretic behaviours.