陈志华^1,2, 黄培华², 余玉洁²
AuthorsHTML:陈志华^1,2, 黄培华², 余玉洁²
AuthorsListE:Chen Zhihua^1,2, Huang Peihua ², Yu Yujie ²
AuthorsHTMLE:Chen Zhihua^1,2, Huang Peihua ², Yu Yujie ²
Unit:1. 水利工程仿真与安全国家重点实验室(天津大学)，天津 300072；2. 天津大学建筑工程学院，天津 300072
Unit_EngLish:1．State Key Laboratory of Hydraulic Engineering Simulation and Safety(Tianjin University), Tianjin 300072, China
2．School of Civil Engineering, Tianjin University, Tianjin 300072, China
Abstract_Chinese:传统防屈曲支撑主要采用内芯截面切削的方式实现局部削弱以提前进入塑性耗能, 而本研究基于局部强度弱化热处理技术, 在不削弱截面尺寸的情况下实现定区域的钢材强度削弱, 提出了新型局部低强防屈曲支撑构造．通过对两种不同方式热处理后的材性试验, 验证了超高温缓慢冷却热处理过程对于钢材强度削弱的有效性以及采用陶瓷加热器系统实现大尺寸构件局部热处理的可行性．通过两组局部低强防屈曲支撑循环往复荷载作用下的拟静力试验, 研究了局部低强防屈曲支撑的耗能性能以及不同约束单元设计对其耗能性能的影响．结果表明：局部低强防屈曲支撑滞回曲线饱满, 延性及抗低周疲劳性能优于普通防屈曲支撑, 且可满足抗震设计的要求, 其破坏模式和耗能能力与外围约束单元强度和刚度有关, 且局部低强防屈曲支撑设计时需考虑外伸连接段稳定问题．
Abstract_English:Traditional buckling-restrained brace(BRB) uses section reduction method to ensure local steel strength weakening and early plasticity development. In this study a local steel strength weakened buckling-restrained brace design is proposed，which realizes regional weakening through steel strength reduction rather than section reduction，by using heat treatment technique targeted at local steel strength weakening. The material tests after two different kinds of heat treatment realization methods indicate that the ultra-high temperature heating and controlled slow cooling process can effectively reduce steel strength. The heat treatment can be applied to large-size structural members by using ceramic electric heating system. Uniaxial cyclic loading tests of two groups of local steel strength weakened BRB specimens were conducted to investigate the energy dissipation capacity as well as the effects of encased restrained design on the energy dissipation capacity. The results show that the structure of this new BRB is applicable and all the hysteresis curves are stable and plump. The ductility and resistance to low cycle fatigue are better than those of traditional BRBs and can fulfill the aseismic design requirements. Failure mode of the proposed BRBs is related to the strength and stiffness of encased restrained braces. The buckling strength at outer connecting parts needs to be considered during future design.
Keyword_Chinese:局部低强防屈曲支撑; 超高温热处理; 滞回曲线; 耗能性能
Keywords_English:local steel strength weakened buckling-restrained brace; ultra-high temperature heat treatment; hysteresis curve; energy dissipation performance

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