基于模态局部化和跃迁的网壳结构损伤指标

Damage Characteristic Vector of Reticulated Shell Structures Based on Mode Localization and Mode Transition

由于模态局部化和模态跃迁使结构损伤前后的振型产生较大差别,二者间的相关性发生较大程度的弱化,基于这一事实,利用结构的振型相关系数,构造出一种对网壳结构局部损伤具有高敏感性的损伤特征向量。该向量构造简单,仅使用少数振型和少量的测试自由度。通过一个网壳结构的算例分析,对所提出的损伤特征向量的性质进行了检验。结果表明,该向量不仅具有较好的空间可分辨性、损伤敏感性和噪声鲁棒性,并且对结构有限元模型误差具有一定的适应性。

Both mode localization and mode transition can make the modes of a structure change a lot before and after its damage,and make the correlation between the modes weaken to a great extent.Based on the fact,using mode correlation coefficient,a damage characteristic vector with high sensitivity is presented for the detection of the partial damage of reticulated shell structures.The vector is simple,and it is composed of several modes and a few test freedoms.Through a numerical example of a reticulated shell structure,the properties of the damage characteristic vector are tested.The results show that the vector not only has fairly good resolution performance,damage sensitivity and noise robustness,but can keep its adaptability to some extent to the error of a structural finite element model.