基于Hilbert-Huang变换的结构损伤识别及振动台试验验证

摘要

结构在强烈地震作用下,构件、节点会产生损伤,刚度、强度等力学性能会降低,结构的动力特性也会改变.分析与处理结构振动信号是结构健康监测和损伤识别的重要手段之一.利用Hilbert-Huang变换,提出利用具有时变规律的瞬时频率和瞬时能量识别结构的损伤演化过程,利用可以反映结构振动能量分布规律的Hilbert边际谱的相对幅值识别结构的损伤位置.通过对一个12层钢筋混凝土框架模型结构振动台试验测点加速度记录数据的处理分析,识别了该模型结构的损伤演化及损伤位置,识别结果与振动台试验的试验现象基本吻合,验证了基于Hilbert-Huang变换可以实现结构的损伤识别.%Damage occurs in components and joints while the structure is affected by strong ground motions. Dynamic characteristics of the structure will change with the deterioration of strength and stiffness. Analyzing and processing the vibration signals is one of mainstream ways for structural health monitoring and damage identification. In this paper, Hilbert-Huang transform is adopted to identify structural damage. Time-varying instantaneous frequency and instantaneous energy is used to identify the damage evolution of the structure. And relative amplitude of Hilbert marginal spectrum is used to identify the damage location of the structure. Finally, the acceleration records at gauge points from the shaking table test of a 12-storey reinforced concrete frame model are processed. Evolution and location of the model damage are identified. Identification results agrees well with experimental phenomena. This indicates that the proposed approaches are capable to identify damage of the structure.