基于热力收缩线特征的电接触载荷衰减状态在线评估方法

提出了一种基于红外特征的在役飞机电接触可靠性在线评估方法。在役飞机长期的振动、腐蚀、高温等环境负荷冲击导致电接触载体表面状况恶化,其程度往往难以定量评估。通过模型机理分析发现,斑点化特征引起接触电阻等可靠性指标下降。然后针对某型电接触载体施加一定的扭矩载荷谱,实时获取电接触部位的“热”信息。在低载荷、临近额定载荷状态下,随载荷状态变化而出现的斑点化特征较为明显。由此认为,将热力收缩线区域最高温度、等温线密集程度、连通区域面积及边界模糊化程度等作为表征指标,能够反映电接触表面施加机械载荷状态的实际衰减程度。因此,该方法可用作在役飞机接触电阻恶化程度的有效评估方法。

Online Evaluation Method of Electrical Contact Load Attenuation State Based on Characteristics of Thermal Contraction Line

An online evaluation method for electrical contact reliability of in-service aircraft based on infrared characteristics is proposed. The long-term vibration, corrosion, high temperature and other environmental loads of in-service aircraft lead to the deterioration of the surface condition of the electrical contact carrier, and its degree is often difficult to quantitatively evaluate. Firstly, it is found that the spotty characteristics cause the decrease of contact resistance and other reliability indexes through model mechanism analysis. Then a certain torque load spectrum is applied to a certain type of electric contact carrier, so as to obtain the "thermal" information of the electric contact part in real time. Under the condition of low load and near rated load, the speckle characteristics appear obviously with the change of load state. It is concluded that the maximum temperature in the area of thermal contraction line, the density of isotherms, the area of connected region and the degree of boundary blurring as the characterization indexes can reflect the actual attenuation degree of mechanical load applied on electrical contact surfaces. So it can be used as an effective evaluation method for the deterioration degree of contact resistance of aircraft in service.