Low-Cycle Reversed Loading Behavior Nonlinear Analysis on Out Stiffener Ring Joint of Concrete Filled Steel Tubular
The result of low cycle reversed loading indicates that，hysteresis loops of out stiffener ring joint performs good plumpness and stability, meanwhile, bulge is observed in the joint region. In order to explain this phenomenon, nonlinear simulation analysis is applied on stiffener ring joint under low cycle reversed loading. The analysis includes hysteretic energy dissipation index of joint, deformation and plasticity development at connection area. The analysis observes that:(1) hysteresis loops of the joint is stable, with the dissipation coefficients all above 2.0,which is in accordance with the criterion of good plasticity; (2) the size of web welding line openings is too large so that hysteresis loops of the connection do not coincide, thus the size of the openings must be controlled in a certain range; (3)obvious deformation is observed in the column wall of the connection region with a similar pattern as the hysteresis loops, which manifests the principle that the hysteresis loop is mainly contributed by the column wall deformation rather than beam end plastic deformation; (4)in the initial stage of low cycle reversed loading, plastic zonal area runs through the annular plate and the plasticity occurs in the beam after a fairly long period. Under reversed loading, as significant deformation occurs in the connection area and plastic zonal area runs through the ring plate, it is concluded that stiffener ring joint does not comply with the principle of “strong joint”.
Chaohe Chen, Yong Huang and Guangfan Li
C. Y. Li et al., "Low-Cycle Reversed Loading Behavior Nonlinear Analysis on Out Stiffener Ring Joint of Concrete Filled Steel Tubular", Advanced Materials Research, Vols. 243-249, pp. 854-859, 2011