附加黏弹性阻尼与金属阻尼耗能的自复位墙结构抗震性能对比分析

相对传统结构,自复位墙结构在地震作用下具有更大的变形能力且几乎无残余位移,但其耗能能力较弱,需采用附加阻尼来增加整体耗能.目前,金属阻尼器已广泛用于自复位墙结构,其可显著减小结构大震下的地震响应,但小震下的位移和加速度减震效果不佳.因此,将小变形下即可耗能的黏弹性阻尼器应用于自复位墙结构中.设计一幢10层自复位墙结构,分别采用黏弹性阻尼器和 U 型金属阻尼器作为附加耗能构件,通过弹塑性时程分析对比采用两种耗能机制的结构地震响应.结果表明,黏弹性阻尼器可显著减小自复位墙结构在小震下的位移和加速度响应;U 型金属阻尼器在中震下开始耗能,在大震和巨震下,其减震效果会超越黏弹性阻尼器.因此,为进一步优化自复位墙结构在不同水准地震作用下的抗震性能,建议结合阻尼器的特点进行合理设计.

Comparative analysis on seismic performances of self-centering wall structures with viscoelastic and metal dampers

Self-centering (SC) wall structures show larger deformation capacity and almost no residual displacement than the traditional structure under earthquake excitation. However, energy dissipaters must be installed to increase the energy dissipation capacity for SC wall structures. Metal dampers are widely used in SC wall structures, which can significantly reduce the seismic response of structures under large earthquakes. However, these dampers have limited effect under small earthquakes. This paper applies the viscoelastic damper, which can dissipate energy under small deformation to SC wall structures. A 10-story SC wall structure was designed with viscoelastic and U-shaped metal dampers as additional energy dissipation components. The comparison between seismic performances of the structure using two energy dissipation mechanisms was conducted through elastic-plastic time-history analysis. Results show that the viscoelastic damper can significantly reduce displacement and acceleration responses under minor earthquakes. However, the energy dissipation capacity of the U-shaped metal damper will surpass that of the viscoelastic damper under large earthquakes. Therefore, the characteristics of different dampers should be considered in the design to further optimize the seismic performance of SC wall structures under earthquakes with different intensities.