建筑结构地震响应混沌特性及影响因素分析

Chaotic characteristics of the seismic response of building structures and analysis of the influencing factors

采用混沌时间序列分析方法分别对以经典混沌信号和地震动为激励的结构响应进行混沌特性分析,从关联维数、Kolmogorov熵及最大Lyapunov指数等定量指标的角度,考察结构自振周期、地震动的类型和幅值等因素对结构地震响应的非线性特性的影响。研究结果表明:在经典混沌信号和地震动作用下,经过结构的放大和滤波作用,结构加速度响应仍然保留了混沌特性,且通过混沌参数的变化程度能够判断结构是否进入弹塑性状态。结构自振周期为结构加速度响应的混沌特性的主要影响因素;幅值对经典混沌信号作用结构下加速度响应的混沌特性影响较为显著;而地震动的类型、幅值等因素对地震动作用下响应的混沌特性影响更为显著。

Chaotic time series analysis method was used to analyze the chaotic characteristics of structural responses excited by classical chaotic signals and ground motions.The effects of natural vibration period and damping,type and amplitude of ground motion on the non-linear characteristics of the structure’s seismic response were investigated from the perspective of such quantitative indicators as the correlation dimension,Kolmogorov entropy and the maximum Lyapunov exponent.Results show that,under the action of classical chaotic signal and ground motion,the acceleration response of the structure retains the chaotic characteristics through the amplification and filtering of the structure.The degree of the variation of chaotic parameters can be used to judge whether the structure has entered the elastic-plastic state.The natural vibration period of the structure is the main factor affecting the chaotic characteristics of the acceleration response of the structure.The amplitude has a significant influence on the chaotic characteristics of the acceleration response under the action of classical chaotic signals,while the type and amplitude of ground motions have a more significant impact on the chaotic characteristics of the response under the action of ground motions.