芯材构造形式对屈曲约束支撑力学性能影响研究

摘要

Four end reinforced and two traditional buckling-restrained braces (BRB) with two sections and two kinds of cross combinations are designed and produced to study the mechanical properties of the buckling-restrained braces with different core construction which are fabricated with Chinese Q235 steel.The hysteresis performance,damage characteristics,mechanical parameter asymmetry,secant stiffness variation,equivalent viscous damping ratio,ductility coefficient and restoring force model are researched through the quasi-static test.The studies show that the core section welded or not has no significant effect on the overall performance and failure mode,and the weld quality and welding residual stresses are the critical factors related to stable performance of the end reinforced buckling-restrained braces.The mechanical properties of the end-reinforced BRB and the cutting BRB have the same variation.The restoring force model can be described by hyperbola.The results show that the structural design of the end-reinforced is scientific and reasonable.%为研究芯材构造形式对屈曲约束支撑力学性能的影响,采用国标Q235钢材设计并制作了两种截面形式、两种组合方式,外围约束机制为矩形钢管混凝土的4根端部加强型屈曲约束支撑试件及2根切削型屈曲约束支撑试件,通过拟静力加载试验,对试件的滞回性能、破坏特征、刚度变化规律、等效粘滞阻尼比、延性系数及恢复力模型等进行了分析.试验表明,内核芯材核心段焊接与否对支撑综合性能及其破坏形态不产生明显影响,焊缝质量及焊接所产生残余应力的大小是影响端部加强型支撑性能稳定与否的关键因素;端部加强型与切削型屈曲约束支撑的力学性能具有相同的变化规律,其恢复力模型均可用双曲线进行描述.结果表明,端部加强型屈曲约束支撑的构造设计是科学与合理的.