弱耦镜像对称工程结构模态局部化度的结构参数表征

模态局部化现象对弱耦镜像对称工程结构的动态分析与主动设计至关重要。基于小参数摄动理论，针对由左右两个完全相同但在几何上互为镜像的子结构所组成失调对称结构，用峰值振幅比定义模态局部化度，重点建立了预测模态局部化发生的定量判据。该判据确立了局部化度的具体数值与结构的几何、质量及弹性等参数之间的直接影响关系。以此为依据，可实现通过失调量的主动设计达到灵活控制模态局部化强弱程度的目的。对一个弱耦近频对称结构的单边刚度失调模型的局部化振动的数值分析结果表明:（1）联结刚度失调产生的模态局部化对失调对称结构的振型将产生显著的影响；（2）验证了所提出的模态局部化定量判据及局部化度的结构参数表征的可行性和有效性。

Characterization for mode localization level of weakly coupled mirroring symmetrical engineering structures with mistuned structural parameters

Based on the perturbation theory of nearly equal frequencies,the phenomenon of mode localization in mistuned weakly coupled mirroring symmetrical structures was studied.The mistuned stiffness and/or mass in these structures resulted in a significant localization of mode,it in turn affected their dynamic behavior and vibration characteristics.Based on the definition of mode localization level using amplitude ratio in symmetrical structures,a quantitative criterion to predict the occurrence of mode localization and its level for mistuned structures with stiffness perturbed was established.The criterion revealed the relationship between the localization level and structural parameters.The simulation results showed that the mode localization is particularly prominent under weak-coupling condition,and the mode localization level can be effectively controlled by changing mistuned stiffness and/or mass parameters.