基于能量指标的高层钢结构动力弹塑性抗震能力研究

能量参数作为结构抗震性能的重要指标,因结构滞回耗能和损伤机理的复杂性而较少被研究或仅对SDOF系统进行能量反应分析;然而,真实的结构是多维空间体系,结构构件在空间上具有协同工作的特点,将低维条件下的研究成果推广到更高维的层次上有一定的局限性。针对该问题,基于能量分析方法,研究了1个3×6跨、18层、高55m的高层钢结构在多维地震荷载作用下的抗震性能。明确结构各种能量成分占总输入能的比例关系、结构的极限耗能能力、层间滞回耗能分布规律、结构的损伤(塑性铰)分布,并讨论了不同加速度峰值下瞬态滞回耗能、滞回耗能幅值谱和由能量分析获得的结构等效阻尼比等诸多参数。基于能量指标的分析方法较好地反映地震荷载作用下结构的抗震性能。

Energy-based study on the dynamic elastic plasticity seismic capacity of a high-rise steel structure

Energy parameters are important but they are either inadequately studied or analyzed only in SDOF systems,due to the complexities of hysteretic energy dissipation and damage mechanism in structures.Structures are multidimensional spatial systems.The results from one or two dimensional cases are not applicable to there or higher dimensional cases.To solve the problem,based on energy analysis method,the performance of a spatial structure with 3×6 bay,18 stories and a height of 55m subjected to multidimensional seismic loads is studied.Energy component proportions in total input energy,ultimate energy dissipation capacity,inter-story distribution of hysteretic energy dissipation and plastic hinge distribution are analyzed,and transient hysteretic energy dissipation,its amplitude spectrum and equivalent damping ratios of the structure under different acceleration peaks cases are discussed.