混合联肢PEC墙结构基于合理失效模式的性能化设计方法研究

Performance-based design method for hybrid coupled PEC wall structure based on reasonable failure modes

基于性能化设计理念,提出了混合联肢PEC墙结构基于合理失效模式的性能化设计方法:以结构达目标位移时实现合理失效模式作为性能目标,基于能量平衡原理确定结构设计基底剪力,并给出符合失效模式的侧向力分布;依据给定目标塑性耦连比分别求解钢连梁和PEC墙肢底部加强区内力需求;采用塑性设计方法设计钢连梁和PEC墙肢底部加强区截面,采用弹性设计方法设计PEC墙肢非加强区截面,保证结构实现预期性能目标。依据提出的基于合理失效模式的性能化设计方法,设计了12层混合联肢PEC墙算例结构,对其进行Pushover分析和弹塑性动力时程分析,验证了该方法的可行性。基于合理失效模式的性能化设计方法设计的混合联肢PEC墙结构抗震性能良好,地震作用下,各层钢连梁首先剪切屈服耗散能量,然后PEC墙肢底部形成弯曲塑性铰,塑性铰分布及发展过程符合预期,实现了“两阶段耗能体系”设计目标。

Based on the concept of performance-based design,a performance-based design method for hybrid coupled PEC wall structures based on reasonable failure modes was proposed.The performance objective was to realize reasonable failure modes during a structure reaching target displacement.Structural design base shear force was determined based on the principle of energy balance,and lateral force distribution in accordance with failure modes was given.Internal force requirements for bottom reinforcement zone of PEC wall limbs and steel coupling beams were calculated based on the given target plastic coupling ratio.The plastic design method was used to design the reinforced zone cross-section at bottom of PEC wall limbs and steel coupling beams,and the elastic design method was used to design the non-reinforced zone cross-section of PEC wall limbs to ensure realizing the structure’s expected performance targets.According to the proposed performance-based design method based on reasonable failure modes,a 12-story hybrid coupled PEC wall structure was designed as an example.Pushover analysis and elastic-plastic dynamic time history analysis were performed for it to verify the feasibility of this method.It was shown that this hybrid coupled PEC wall structure designed with the performance-based design method based on reasonable failure modes has good aseismic performance;under seismic action,its various stories’steel coupling beams firstly dissipate energy with shear yielding,and then bending plastic hinges are formed at bottoms of PEC wall limbs,plastic hinges’distribution and development processes are in accordance with expectations to realize the design goal of a“two-stage energy-dissipation system”.