民用飞机机体连接结构动刚度计算分析及试验验证

Dynamic Stiffness Analysis and Test Validation on Connecting Structure of Civil Aircraft

目的通过分析和试验得到民用飞机机体连接结构动刚度。方法通过理论分析,得到动刚度的推导公式,并运用有限元分析软件进行频响分析,进而得到连接结构动刚度。运用锤击法得到动刚度试验数据,并进行试验验证。结果试验结果受信号衰减的影响,低频范围内较难得到静刚度结果,但可以通过分析模型得到。试验刚度结果开始波动较大,但在高频范围趋于稳定,最终稳定在分析刚度值左右。当动刚度分析结果受频率影响变化不大时,可以采用动刚度分析均值来作为不同频率下的刚度值。结论通过频响分析得到民用飞机某种结构的动刚度变化曲线,并通过动刚度试验进行了试验验证,分析对比结果表明,有限元分析可以较为准确地得到机体支持结构动刚度,并用于工程实际。

Objective To get the dynamic stiffness of civil aircraft by analysis and test.Methods Theoretical method was used to get the derivation formula of dynamic stiffness and the FEM software was used to have frequency response analysis to get the dynamic stiffness of connecting structure.Hammer test was also carried out to get data on the dynamic stiffness test and carry out experimental verification.Results The test results were affected by signal attenuation.It was hard to get static stiffness under low frequency.But it could be obtained by model analysis.The test result of dynamic stiffness did not fluctuate greatly in the beginning,tending to be stable in the range of high frequency and was finally stabilized near to the stiffness value.When the dynamic stiffness was not affected much by frequency in analysis results,then the average dynamic stiffness in analysis result can be used as the finally stiffness for different frequency.Conclusion By frequency response analysis,the curve of dynamic stiffness for connecting structure of civil aircraft is get.The FEM method is confirmed by dynamic stiffness test.From the comparison,it can be seen that the FEM method can get the accurate dynamic stiffness and can be used in the engineering practice.