一种诊断复合材料层合板损伤的频响方法

本文首先选取对故障比较敏感,又能反映结构动力学特性的频响函数作为诊断故障的参数。通过计算无损板在给定模态下各单元的模态能量,求得每个单元对该阶模态下全板能量的贡献,并由模态实验得到损伤前后频响函数在各阶共振峰处的变化。分析发现两者之间存在内在联系,从而得到一种分析小损伤位置和范围的新方法。

A Frequency Response Diagnostic Method for Damage Detection of Composite Laminated Plates

In this paper, a new Frequency Response Function (FRF) diagnostic method is proposed for damage detection of composite laminated plates. The method chooses FRF. which is relative sensitive to the damage and can reflect structure dynamic property. as the diagnostic parameter, and calculates the distribution of modal energy of undamaged plate. The relationship between the variation of FRF at different-order resonant peak after damage and the modal energy contribution in each element of undamaged plate in given mode is derived by the theoretic analyses and calculations. Then, the new method is obtained to detect the small damaged element or area. An important conclusion of this method is that, in case of small damage, the ratio of each order modal energy contribution in an element or area is approximately equal to the ratio of change rate at each order generalized FRF resonant peak of undamaged plate in the corresponding damaged element or area. Energy distribution diagrams are given for damage analyses. The results of illustrative examples and experiments show that the method proposed by the authors is effective and feasible.