布设自复位SMA摩擦阻尼器的框架结构减震优化设计方法研究

SEISMIC DESIGN OPTIMIZATION OF FRAME STRUCTURE WITH SELF-CENTERING SMA FRICTION DAMPER

  • 摘要: 建筑结构消能减震优化设计是通过调整消能减震装置在结构中的布设位置和布设数量,以满足不同水准地震作用下结构受力变形需求。该文将形状记忆合金(Shape memory alloy, SMA)和摩擦材料相结合,提出了一种新型自复位SMA阻尼器,将其布设于框架结构中以降低结构的地震响应。以四水准抗震设防目标下结构峰值层间位移角为约束条件,建立了基于循环迭代法和回溯搜索优化算法的两阶段结构减震优化设计方法。第一阶段通过在结构中逐次增设阻尼器数量开展循环迭代,寻求结构中阻尼器使用总数量;第二阶段使用基于全局搜索机制的回溯搜索优化算法开展二次优化计算。通过上述方法对9层Benchmark钢框架结构进行了减震优化设计,结果表明:所提出的两阶段减震优化设计方法可得到经济合理的阻尼器布设方案,优化后结构各楼层层间位移角沿楼层分布更为均匀,在阻尼器总数量最小的情况下保证减震结构在地震作用下可满足预设的层间位移角限值。

     

    Abstract: The goal of seismic design optimization of buildings is to meet the requirements on loading capacity and deformation under different levels of earthquake by adjusting the location and number of energy-dissipation devices. An innovative self-centering damper is proposed in this paper which consists of shape memory alloy (SMA) and friction material, and can be installed in frame structures to reduce the seismic response. Taking the inter-story drift ratio (IDR) under the four-level seismic fortification targets as the constraint condition, a two-step design optimization method is proposed based on cyclic iterative method and backtracking search optimization algorithm (BSA). Firstly, cyclic iterations are carried out by increasing the number of dampers in the structure one by one to find the total number of dampers. Then the BSA based on global search mechanism is used to conduct the re-optimization. Seismic design optimization is conducted for a nine-story benchmark building by the aforementioned method. Results show that the proposed method can generate a reasonable placement scheme of dampers. The IDR of the optimal structure is more evenly distributed along the floor, which satisfies the preset IDR limit under seismic loading with the minimum number of dampers.

     

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