SDOF体系地震输入能及其分配问题研究

Study of earthquake input energy and its distribution for SDOF system

目前对地震能量方面的研究工作多集中在地震总输入能和结构总滞回耗能的估算上,忽略了能量反应的时变特征。本文基于能量平衡原理,通过Matlab自编程序对比分析了SDOF体系在弹性无阻尼、弹性有阻尼、弹塑性双线型和弹塑性三线型四种滞回模型下的地震能量时程反应,进而探讨了SDOF体系地震能量时程反应、总输入能及瞬时输入能分配的规律。结果表明:滞回模型选取对弹塑性SDOF体系非动能项影响较大;不同滞回模型下SDOF体系地震输入能的大小关系为:弹塑性体系<弹性体系,弹性有阻尼体系<弹性无阻尼体系,弹塑性三线型<弹塑性双线型。

Presently most works for seismic energy analytical methods are focused on the estimation of the total input energy and the total hysteretic one, while the time-variation characteristics are always ignored. Based on the energy balance principle, using a Matlab software, the seismic response time history analysis for SDOF systems is carried out, in which the elastic system with and without damping, the elastic-plastic double linear hysteretic model and the three linear stiffness degradation model are considered, respectively. Then the time history response of the energy terms, the distribution of the total input energy and the momentary input energy for SDOF systems are analyzed. The results show that the energy terms for the elastic-plastic SDOF systems are sensitive to the hysteretic model in addition to the kinetic one. The value features of the seismic input energy for different types of SDOF systems are the elastic one is more than the elastic-plastic one, the elastic without damping one is more than the elastic with damping one, the one with the elastic-plastic double linear hysteretic model is more than the one with the three linear stiffness degradation model.