【摘要】 如何简便合理地确定组合结构的整体阻尼比是结构抗震设计中的重要内容.在动力时程分析时,结构系统是确定的,然后对结构施加不同的作用,来求解结构的响应.基于此点,本文从振型能量角度出发,提出一种求解多维地震作用下空间结构整体阻尼比的新方法.在结构模型确定后,可根据动力时程分析所要输入结构的地震波的情况,估算结构的整体阻尼比,通过计算得出此法所需截取的振型数可以按照"振型参与质量达到总质量的90%"的原则进行确定.并将此法计算的阻尼比与位能加权平均法进行了对比,认为在进行时程分析时,阻尼比应根据要输入的地震动及结构来确定,计算结果才会更加合理.更多还原

【Abstract】 Calculation of damping ratio about the overall model of composite structure is essential to the earthquake-resistant design.Structural system is definite when dynamic time-history analysis method is used.The response of structure is not only related to the structural system,but also to the earthquake wave properties.Damping ratio about overall models of spatial structure should be calculated considering the response to the dynamic load.A new method for estimating damping ratio of overall models under multi-dimensional earthquake is put forward based on modal energy.The number of modes of vibration for this method can be determined by the principle that the sum of modal participating mass ratio should exceed 90%.This method is compared with the potential energy weighted average method which is generally applied in the domestic engineering domain.Computation considering both structural system and dynamic load for the damping ratio about overall models of spatial structure is more reasonable.更多还原