基于HHT变换的结构地震响应与能量计算分析

为了更好地研究地震动激励与结构响应之间的定量关系,通过HHT变换得到瞬时能量谱、Hilbert能量谱以及三维幅值谱,研究了基于HHT变换的结构地震反应的能量计算方法.提出了以地震动峰值能量的最大值和峰值系数作为地震对结构破坏的定量指标的概念。通过算例计算了地震动和结构位移的能量,求出了各种地震波峰值能量的最大值和峰值系数,得到结构各层能量与反映非平稳特征的峰值系数的关系。结果分析表明,基于HHT变换的结构地震能量计算,更加明确了地震波在结构传播过程中能量的变化规律,计算结果的精度可以满足工程设计要求.初步建立了地震动对结构破坏的强弱的判据,该判据是可行和可靠的.可为工程抗震设计和结构控制等研究提供重要的基础资料.

Computation and analysis of seismic response and energy based on Hilbert-Huang transform

For better research of numerical relation between earthquake stimulation and structural response,instant energy spectrum,Hilbert energy spectrum and three-dimensional amplitude spectrum is obtained by Hilbert-Huang transform(HHT);and energy computation method of seismic response of structure is studied based on HHT.Moreover,the concept that shall be used as the numerical index of structural damage which is caused by earthquake is proposed.In the case study the earthquake and energy of structural displacement is calculated;the maximum value and peak coefficient of peak energy of earthquake is derived;and the relation between the energy of each structural storey and the peak coefficient reflecting nonstable characteristics is finally derived.The analytical result reveals that the computation of seismic energy of structure based on HHT makes clear that the rule of energy variation of earthquake wave during its dissemination in structure.The precision of computation result satisfies the requirement for engineering design.The criterion for the judgment of structural damage caused by earthquake is initially established,which is feasible and reliable.The useful conclusion provides important and basic data for the research of engineering aseismic design and structural control.