摘要:
复合材料故障诊断问题日益受到人们的重视。利用振动理论和实验技术进行故障诊断是一种很有吸引力和值得探索的方法。本文提出了一种复合材料层合板损伤的频响一能量诊断新方法,此方法选取对故障比较敏感,又能反映结构动力特性的频响函数作为诊断故障的参数,并引入阻尼耗散能计算本文定义的无损板在各阶模态下广义模态能量的分布,通过理论推导和计算得到了损伤前后频响函数在各阶共振峰处的变化,与无损板在给定模态下各单位的模态能量贡献之间的联系。从而得到一种分析小损伤位置和范围的新方法。此方法的一个重要结论是:在小损伤的前提下,对于同一单元或同一区域各阶广义模态能量贡献之间的比值,同假设这一单元或区域有损伤而得到的各阶频响函数在无损板峰值处的变化率之比基本相等。文中提供了能量贡献分布图等,可供分析之用。算例与实验的结果表明,本文提供的方法是有效,可行的。
Abstract:
Fault diagnosis of composite structure is increasingly of great interests.It is attractive to diagnose damage by means of vibration theory and experimental technique.In this paper,a new Frequency Response Function (FRF)-Modal Energy diagnositic 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 charateristic,as the diagnostic parameter,and lead to concept of damped dissipative energy and calculates the distribution of generalized modal energy of undamaged plate defined in the paper.The relationship between the varition of FRF at different-orderd resonant peak after damage and the modal energy contribute in each element of undamaged plate in given mode is derived by the theory analyses and calculations.Then,the new method is obtanned to detect the small damaged element or area.An important conclusion of this method is that,in the case of small damage,the ratio of each order generalized modal energy contribution in an element or area is approximately equal to the ratio of change rate at each order 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 aushors is effective and feasible.
百度学术
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