基于IDA 方法的钢筋混凝土结构失效模式优化
OPTIMIZATION OF FAILURE MODES FOR REINFORCED CONCRETE BUILDINGS BASED ON IDA METHOD
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摘要: 结构失效的关键在于非最优的失效模式导致结构不能承受最大的外部荷载。为改善结构的失效模式,采用OpenSees软件建立一个5 层3跨的钢筋混凝土框架纤维模型。按场地条件选取10 条不同的地震动对结构进行增量动力分析(IDA),结合IDA曲线的特征和结构的失效准则,提出基于IDA方法的结构最弱失效模式。最后提出3种方案对结构进行失效模式优化,其中以综合考虑失效路径中失效截面的先后顺序和形成“强柱弱梁”型全梁铰式耗能失效机制的方案最优,其结构的抗震能力最强。基于IDA 方法的结构失效模式优化,可广泛用于其它结构形式,为工程结构抗震能力的提高开辟了一种新的方法。Abstract: The structure's failure to withstand heavier loads is primarily caused by their unreasonable failure modes. In order to optimize the failure modes of structures, a five-storey and three-bay reinforced concrete plane frame is established, based on the fiber model using OpenSees. Ten different ground motions are selected according to the site conditions as the input of an IDA analysis. The weakest failure mode of the structure under the failure criterion is obtained based on IDA curves. Finally, three approaches are employed to improve the structure's failure modes. The results considering both the order of the failure section in the failure path and energy dissipation occurring only in beam sections to achieve the “strong column weak beam”, have the best superiority to improve the seismic performance. The optimization of structure's failure modes based on the IDA method can also be applied to other structural systems, providing a new way for the seismic design.