【摘要】 综合考虑强度退化、刚度退化、捏拢效应等典型滞回特性的影响,建立了双向地震作用下平面不对称结构非弹性地震动力响应分析的平扭耦联Bouc-Wen模型。该模型采用圆形屈服面来描述双向抗侧恢复力之间的耦合效应,而采用锥体或球体屈服面来描述双向抗侧和抗扭恢复力之间的耦合效应,并结合69条强震记录,定量地分析了平扭耦联效应对平面不对称结构地震延性需求的概率统计特征的影响。计算结果显示:球体屈服面比锥体屈服面更能合理描述双向抗侧恢复力和抗扭恢复力之间的耦合效应;地震延性需求的均值随着规一化屈服强度和非耦联平动自振周期的减小而增大。当非耦联平动自振周期较大时,地震延性需求的均值的对数与规一化屈服强度的对数近似成线性关系。平扭耦联效应可以明显增大地震延性需求的变异性,当非耦联平动自振周期和规一化屈服强度较小时尤为明显。更多还原

【Abstract】 A new lateral-torsional coupling Bouc-Wen model for inelastic seismic dynamic response analysis of plan-asymmetric structure under bidirectional horizontal excitations was developed considering the strength degradation,stiffness deterioration and pinching effect.In this model,the circular yield surface is adopted to describe the coupling effect between biaxial normalized lateral restoring forces,while the pyramidal or spherical yield surface is adopted to consider the coupling effect between lateral and torsional restoring forces.The influence of lateral-torsional coupling on the statistical characteristic of seismic ductility demand of plan-asymmetric structure was investigated using 69 earthquake records.Analysis results show that the spherical yield surface is better than the pyramidal yield surface to describe the lateral-torsional coupling effect.The mean value of seismic ductility demands increases with the decrease of the normalized yield strength and the uncoupled lateral vibration period.The relation between the logarithms of the seismic ductility demand and the normalized yield strength is almost linear,when the uncoupled lateral vibration period is long.The lateral-torsional coupling effect can amplify the variation of the seismic ductility demands obviously,especially when the normalized yield strength is small and the uncoupled lateral vibration period is short.更多还原