应用弹塑性反应谱对IDA方法的改进研究

针对传统IDA方法中结构的加速度反应远高于SPO分析结果的现象,采用弹塑性反应谱作为IDA的烈度度量,同时给出随地震烈度改变而不断变化的屈服强度系数,提出了改进的IDA方法,更有效地考虑了结构的非线性地震反应特征。实际工程分析表明,改进的IDA方法能够体现结构的非线性受力反应,同时兼顾结构的动力反应特征,与SPO曲线和由规范计算得到的结构承载力有更好的可比较性。

Research on modified IDA method by inelastic response spectrum

The traditional increment dynamic analysis(IDA) method gave larger acceleration response than that by nonlinear static pushover(SPO) analysis.The inelastic response spectrum is used as an intensity magnitude,and the yield strength factors are continuously changed with the different seismic intensities.So the modified IDA method is suggested,which can consider the character of the structures' inelastic seismic response more effectively.The practical engineering analysis results indicate that the modified IDA analysis can give more accurate nonlinear seismic force on structures,and the structural dynamic response under earthquakes.The relationship between the modified IDA curves and the SPO curves or the strength lines of structures calculated by the seismic standard can be set up more easily.