耗能梁段的构造对K型偏心支撑钢框架受力性能的影响

对具有不同加劲肋间距和厚度的K型偏心支撑钢框架的滞回性能与耗能梁段的破坏模式进行了非线性有限元分析,结果表明:腹板加劲肋可加强腹板的抗剪刚度,阻止或延缓对角拉伸带的形成,同时减少由于腹板反复屈曲变形所产生的刚度和承载力退化,使耗能梁段的耗能能力能够得以充分发挥.厚度较小的加劲肋对耗能梁段腹板的受剪刚度和屈曲后的强度贡献亦较小,其在耗能梁段腹板达到剪切屈服时不能有效地阻止腹板屈曲变形的发展,最终导致框架的耗能性能下降,而加劲肋过厚则对框架的受力性能无明显改善.并根据有限元模拟结果对耗能梁段的构造提出了设计建议.

Effects of the link's configuration on load-bearing characteristic of K shape eccentrically braced steel frames

The nonlinear FEM analysis is carried out on the K shape eccentrically braced steel frames' hysteretic behavior and links' failure mode on the basis of different distance and thickness of the ribs.The analysis indicates that the rib can reinforce the shear-resistance stiffness of the web,and restrain or delay the formation of the diagonal tension strip.Furthermore,the rib can reduce the deterioration of the stiffness and load-bearing characteristic caused by the repetitive bucking deformation of the web,and make the energy-dissipation capacity of the links fully develop.The thinner of the rib,the smaller the stiffness of the shear-bearing and post-buckling strength of the links are.Additionally,the thinner rib can't prevent the web buckling deformation effectively when the web of links reached the shear-yielding strength.This would result in the energy-dissipation capacity of the frame descends,but the thicker rib can't improve the load-bearing characteristic of the frame effectively.Based on the FEM simulation results,the proposal is given for the designing of the configuration of the link.