循环冲击作用下缺陷飞机液压管路微泄漏故障诊断

Fault Diagnosis of Micro-leakage in Hydraulic Pipeline of Defected Aircraft Under Cyclic Impact

带有表面微缺陷的飞机液压管路在循环压力冲击作用下会逐渐形成非贯穿裂纹,但是随着裂纹处应力的循环作用,会扩展成贯穿性微裂纹,导致管路产生微泄漏。基于管路内瞬变流数学模型,采用AMESim软件对循环压力冲击载荷下飞机液压管路泄漏故障进行模拟,分析不同泄漏情况对管路压力信号波形的影响;然后根据管路压力信号波形的仿真结果,通过Daubechies小波系中5类小波函数分别对其进行小波分解,分析并对比小波函数的分解结果,选取最优小波函数分解结果定位信号中奇异点位置;最后开展管路泄漏故障实验,通过最优小波函数和负压波定位法检测及定位管路泄漏位置。研究成果为飞机液压管路泄漏故障诊断提供新的方法,同时,为我国飞机液压管路视情维修模式进行探索。

Micro-defects on the surface of the aircraft hydraulic lines can gradually form non-penetrating cracks under the cyclic pressure;but with the cyclic action of stress;cracks may expand into penetrating micro-cracks;resulting in micro-leakage of pipelines.In this paper;AMESim software is used to simulate the leakage failure of aircraft hydraulic pipeline under the cyclic pressure impact load;based on the mathematical model of transient flow in pipeline.In addition;the influence of different leakage conditions on the pipeline pressure signal waveform is analyzed.Then;according to the simulation results of the pipeline pressure signal waveform;the wavelet decomposition is carried out using 5 kinds of wavelet functions in Daubechies wavelet system.The decomposition results of the wavelet function are analyzed and compared.The optimal wavelet function decomposition results are selected to locate the singularity points in the signal.Finally;the pipeline leakage fault experiment is carried out to detect and locate the pipeline leakage location through the optimal wavelet function and the negative pressure wave location method.Results provide a new method for the fault diagnosis for the aircraft hydraulic pipeline leakage.