不同锈蚀程度下Q235钢框架梁恢复力模型研究

Study on Restoring Force Model of Q235 Steel Frame Beam in Different Corrosion Degrees

为研究不同锈蚀程度下Q235钢框架梁的力学性能,基于Q235钢框架梁抗震性能试验,通过对6根锈蚀程度不同钢框架梁试件的低周反复荷载试验,根据试验结果得到其滞回曲线、骨架曲线及刚度退化规律,分析试验数据得到不同锈蚀程度对钢框架梁抗震性能的影响.引入循环退化指数,拟合了具有累计损伤效应的特征点(屈服点、极限点、破坏点)公式,提出了适用于锈蚀钢框架梁的滞回规则,进而建立了考虑锈蚀作用的钢框架恢复力模型.其中3根试件进行模拟曲线与试验曲线的对比,另3根试件进行模拟曲线与有限元分析的对比,对比结果表明恢复力模型有较高的精度,吻合情况良好,所建恢复力模型可为不同锈蚀程度的钢框架梁分析提供理论依据,为钢框架梁在不同锈蚀程度下的弹塑性分析奠定了基础.

To study the mechanical properties of Q235 steel frame girder in different corrosion degrees,low frequency cyclic loading test on steel frame girders of six trusses in different corrosion degrees was carried out on the basis of seismic performance test of steel frame girders. The hysteresis curve,skeleton curve and rigidity degeneration rule were obtained based on the text results. The effect of different corrosion degrees on seismic performance of steel frame beams was acquired by analyzing text data. The cyclic degradation index was introduced,and the characteristic point (yield point,limit point and breaking-down point) formula with cumulative damage effect was fitted. The hysteretic rule applied to rusted steel frame girders was put forward,and then the restoring force model of steel frame with the consideration of corrosive action was established. The comparison between the simulation curve and text curve for the samples of three trusses was performed,and the comparison between the simulation curve and finite element analysis for other samples of three trusses was implemented. The comparison results show that the restoring force model has high precision and better tally,the established restoring force model can provide theoretical basis for the analysis on steel frame girders in different degree of corrosion and lay a foundation for elastic-plastic analysis steel frame girder in different degree of corrosion.