基于滞变阻尼模型的反应谱CQC法

A response spectrum CQC method based on hysteretic damping model

复阻尼模型具有每周期耗散能量与外激励频率无关的优点,但自由振动解中存在发散项。基于复阻尼模型的等效滞变阻尼模型不仅保留了相应的优点,且克服了时域发散的缺陷。本文在模态叠加法的基础上,提出了基于滞变阻尼模型的反应谱CQC法,并利用时域精确解验证了所提方法的正确性。在此基础上,以反应谱和相关系数为分析对象,对比了基于滞变阻尼模型的反应谱CQC法和基于黏性阻尼模型的反应谱CQC法。算例分析表明:小阻尼比情况下,两种方法的计算结果近似相等;大阻尼比情况下,两种方法计算所得的反应谱值和相关系数皆差异较大;大阻尼比结构需依据结构材料的阻尼特性,选择合适的反应谱CQC法。

The advantage of the complex damping model is that energy consumption is not related to external excitation frequencies in each cycle.However,there is divergent item in the free vibration solution.The hysteretic damping model is obtained based on the complex damping model.Based on the hysteretic damping model,the advantage can be retained and the shortcoming of time-domain divergence can be also overcome.In this paper,a response spectrum CQC method of the hysteretic damping model is proposed based on mode superposition method.At the same time,the correctness of the proposed method is verified by time-domain exact solution.On the basis,the response spectrum and correlation coefficient are analyzed,and the response spectrum CQC methods of the hysteretic damping model and viscous damping model are compared.The cases show that the calculation results of the two methods are approximately equal in the small damping cases.In the big damping cases,the calculated spectral values and correlation coefficients of the two methods are obviously different.For the structures with large damping ratio,a reasonable CQC method of response spectrum should be selected based on the damping characteristic of structural material.