延性交错桁架钢框架双槽钢组合H型截面弦杆恢复力模型研究

摘要

为了建立延性交错桁架钢框架双槽钢组合H型截面弦杆的恢复力模型,对8个双槽钢组合H型截面足尺试件进行往复弯曲下的滞回性能试验.试验参数包括填板间距、侧向支撑设置、加劲肋设置.研究了双槽钢组合H型截面构件在往复弯曲下的滞回曲线、骨架曲线、刚度退化规律.试验结果表明,减小填板间距、在塑性铰处设置侧向支撑,可以限制构件发生单肢失稳及整体弯扭失稳;在此前提下,塑性铰区域设置加劲肋可确保构件发生屈服耗能,提高构件的滞回耗能能力.基于试件SJ6～SJ8的试验数据,采用回归分析的方法建立延性交错桁架钢框架双槽钢组合H型截面弦杆的恢复力模型.对比分析表明,该模型的计算结果与试验结果吻合良好,可用于结构的弹塑性分析.%In order to set up the restoring force model of steel double-channel built-up chords of the special staggered truss steel frame structure,the quasi-static tests on eight full-scale double-channel built-up members under cyclic bending were conducted.The main parameters consist of stitch spacing,lateral support settings and stiffeners settings.The hysteretic curves,skeleton curves and the law of stiffness deterioration of double-channel built-up members under cyclic bending were obtained.Experimental results indicated that the reduction in stitch spacing and the lateral support adjacent to the plastic hinge could prevent the lateral-torsional buckling of the individual channel and the entire member.The stiffeners located at the plastic hinge region could assure members yield and dissipate energy firstly instead of buckling,performing good seismic behavior.Based on the experimental data of Specimens 6-8,the restoring force model of the members was built through regression analysis method.Comparison analysis showed that the model calculating results and experimental results were in good agreement,and could be used for elastoplastic analysis of special staggered truss frame structure.