基于压缩采样和模态分析的冲击载荷反演研究

摘要

近年来,许多学者针对大型飞行器结构的冲击载荷识别进行研究,以期提高这些结构的安全性、降低维护费用、延长使用寿命.在大型结构健康监测中,如何快速、准确地获得冲击力是一个值得深入研究的问题.提出了基于数据的模态分析方法,取代基于有限元分析的模态分析方法,解决传统载荷反演需要依赖结构力学模型的问题;并引入压缩采样理论,基于压缩采样理论提出了一种冲击载荷识别方法,其中包含了稀疏模型,即采样矩阵,还包含重构优化模型;该方法可以解决存储及传输的响应数据过于庞大的问题.最后,用一块大型航空铝板仿真实验来举例说明该冲击力识别方法,结果显示,该方法能够快速、准确地识别出作用在大型结构上的冲击力.%Recently,the scholars have studied the impact force identification in aircraft primary structures in order to improve the operation safety of these structures,reduce the maintenance costs and prolong the service life.How to obtain the impact force quickly and accurately is a worthy subject of in-depth study in the structural health monitoring.The method of modal analysis based on data is proposed to solve the problem that traditional load inversion depends on structural mechanics model,which replaces the modal analysis method based on finite element analysis.Based on the theory of compression sampling,a new method for the identification of impact load is presented,which includes the sparse model,that is,the sampling matrix,and the reconstruction optimization model.This method can solve the problem that the response data are too large.Finally,an example of a large aluminum plate is used to illustrate the impact force identification method.The results show that the method can quickly and accurately identify the impact force on the large structure.