EI、Scopus 收录
中文核心期刊

基于频率相关黏性阻尼模型的复模态叠加法

COMPLEX MODE SUPERPOSITION METHOD BASED ON FREQUENCY DEPENDENT VISCOUS DAMPING MODEL

  • 摘要: 黏性阻尼模型存在每周期耗散能量与外激励频率相关的缺陷, 复阻尼模型时域计算结果存在发散现象. 为克服上述两种阻尼模型的不足, 在复阻尼模型基础上, 依据时频域转化原则推导了频率相关黏性阻尼模型. 频率相关黏性阻尼模型不仅具有每周期耗散能量与外激励频率无关的优点, 还保证了结构位移时程的稳定收敛. 混合结构由具有不同阻尼特性的材料组成, 其阻尼矩阵为非比例矩阵, 无法直接采用实模态叠加法. 根据频率相关黏性阻尼模型与复阻尼模型的转换关系, 提出了适用于混合结构的基于频率相关黏性阻尼模型的复模态叠加法. 算例分析结果表明, 与基于黏性阻尼模型的复模态叠加法相比, 基于频率相关黏性阻尼模型的复模态叠加法不仅计算结果唯一, 且不增加矩阵维度, 具有较高的计算效率. 小阻尼情况下, 两种方法的计算结果近似相等, 且与复阻尼模型的频域计算结果一致. 当阻尼比较大时, 两种方法的计算结果差异增大, 但频率相关黏性阻尼模型的复模态叠加法与复阻尼模型的频域计算结果仍保持一致.

     

    Abstract: According to the viscous damping model, energy dissipation is related to external excitation frequencies in each cycle. There is divergence in time domain calculation results of complex damping model. In order to overcome the two kinds of disadvantages of damping models, frequency dependent damping model is obtained by time-frequency transformation principle on the basis of complex damping model. Energy dissipation is not related to external excitation frequencies in each cycle. In addition, time-history calculation of frequency dependent damping model is convergent. Real mode superposition method is not directly adopted, because the damping matrix of mixed structure of multiple damping characteristic materials is non-proportional. By the transformations of frequency dependent damping model and complex damping model, complex mode superposition method is proposed based on frequency dependent damping model. And it can be directly applied to mixed structure. The analysis results of the cases show that compared with complex mode superposition method based on viscous damping model, the calculation results of the complex mode superposition method based on frequency dependent damping model are unique. In addition, the method does not increase matrix dimensions and has high computational efficiency. The analysis results of small damping cases show that calculation results of the two methods are approximately equal. They are consistent with frequency domain calculation results of complex damping model. When the damping ratios are larger, the difference of calculation results by the two methods will increase. While the calculation results of complex mode superposition method based on frequency dependent damping model will remain consistent with frequency domain calculation results of complex damping model.

     

/

返回文章
返回