加劲肋加强大尺寸焊接方管K型节点滞回性能分析

Analysis of Hysteretic Behavior of Stiffener Strengthen Large-Sized Welded Square Tube K-Joints

目的研究加劲肋加强节点各尺寸参数对节点极限承载力的影响,评价加劲肋加固后大尺寸焊接方管K型节点的抗震性能.方法在试验与有限元分析对比的基础上对节点进行拟静力滞回分析,研究在加劲肋开洞直径R、加劲肋厚度tw、支管间隙a、主支管夹角θ不同情况下的承载力、延性系数、滞回环形状、能量耗散系数E,来评价这种节点的抗震耗能能力.结果节点的滞回面积、延性系数和能量耗散系数等数据表明:参数θ对能量耗散系数E影响最大,支管间隙α为零时对抗震最不利,加劲肋加强大尺寸方管K节点比无加劲肋节点延性系数高36%,极限承载力提高28%,有加劲肋加强的节点滞回曲线饱满,具有更好的抗震性能.结论加劲肋不仅能大幅提高节点极限承载力,而且可以大大改善节点抗震性能。

This paper was proposed to study the impact of node size parameters on the ultimate bearing capacity of stiffener strengthen joint, in order to evaluate the seismic performance of the stiffener strengthen large-sized welded square tube K-joints. The pseudo-static hysteric property was investigated based on the comparison results between test and finite element analysis to evalu- ate the seismic capacity of this type joint, including the ultimate bearing capacity, ductility coeffi- cients, the shape of the hysteresis loop, energy dissipation coefficient E impacted by stiffener diam- eter R, stiffener thickness tw, gap a between branch pipe, angle 0 between the branch pipe and the main pipe. The data showed that the parameter a showed the greatest influence on the energy dissi- pation coefficient E;the seismic performance was the worst when the gap a was zero;the ductility coefficients of the stiffener strengthen large-sized welded square tube K-joints was 36% larger than that without stiffener joints, the ultimate bearing capacity was 28% larger than that without stitten- er joints, the hysteresis loop of stiffener strengthen joints were plump with better seismic capacity. It can be concluded that the rib stiffener could greatly increase the ultimate bearing capacity of large size box-K-joint to improve its seismic performance.