基于Rayleigh阻尼模型的竖向混合结构设计阻尼比研究

发布时间：2018-05-01 13:17

本文选题：竖向混合结构 + 等效阻尼比　；参考：《工程力学》2015年10期

【摘要】：由两种或两种以上不同材料串联组成的竖向混合结构,结构阻尼特征空间分布存在明显差异,这使得整体结构地震作用下的动力响应难以估计。对于结构初步抗震设计,特别是采用常规商用软件进行分析时,往往需要确定结构的阻尼比系数,这就需要引入等效阻尼比的概念。该文基于Rayleigh阻尼模型,推导了竖向混合结构在谐振荷载下的近似解耦位移响应误差函数,由随机地震动激励下位移响应误差最小,得到最佳等效阻尼比计算公式。将竖向混合结构等效成两自由度结构模型,每一自由度的动力特性由对应子结构的主频确定,对该两自由度模型进行不同子结构特性下最佳等效阻尼比分布和位移响应误差分析。结果表明:采用该文给出的最佳等效阻尼比,能更合理地预测结构在地震作用下的位移响应;而简单地采用单一材料结构阻尼比进行分析,可能会过高或过低估计结构耗能能力。
[Abstract]:The vertical mixed structure consisting of two or more than two different materials in series has obvious difference in the spatial distribution of structural damping characteristics, which makes the dynamic response of the whole structure difficult to estimate. For the preliminary seismic design of the structure, especially by the conventional commercial software, the damping ratio of the structure often needs to be determined. The concept of the equivalent damping ratio is introduced. Based on the Rayleigh damping model, this paper derives the approximate decoupling displacement response error function of the vertical hybrid structure under the resonant load. The minimum displacement response error is minimized by the random vibration excitation, and the optimum equivalent damping ratio is obtained. The vertical mixed structure is equivalent to two freedom. The dynamic characteristic of each degree of freedom is determined by the main frequency of the corresponding substructure. The optimal equivalent damping ratio distribution and the displacement response error of the two degree of freedom model are analyzed under different substructure characteristics. The results show that the optimum equivalent damping ratio given in this paper can be used to predict the displacement of the structure more reasonably under the earthquake action. A simple analysis of the damping ratio of a single material structure may be too high or too low to estimate the energy dissipation capacity of the structure.

【作者单位】：同济大学土木工程防灾国家重点实验室;
【基金】：国家“十二五”科技支撑计划项目(2012BAJ13B02) 国家自然科学基金项目(51078274)
【分类号】：TU398.9

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