Leading indicators for prognostic health management of electrical connectors subjected to random vibration

In this paper a leading indicators of failure has been developed to monitor the progression of fretting corrosion in electrical connectors and prognosticate remaining useful life. Connectors subjected to harsh environments may experience vibration resulting in fretting corrosion and degradation in contact resistance over time. Tin coated, rectangular-pin and socket electrical connectors have been studied. Connectors are extensively used in automotive systems in conjunction with wire harnesses. Electronics may be full filling many vehicle performance critical functions including: collision avoidance, lane departure warning, supplemental restraint, and driver distraction detection. Connector degradation may cause electrical failure during or prior to vehicle operation. In this paper, a random vibration test profile has been used to stimulate the contact resistance degradation due to connector fretting corrosion. The contact resistance has been measured in situ using the resistance spectroscopy method in conjunction with phase sensitive detection. It has been shown that precise resistance spectroscopy and phase measurements can provide a leading indicator of failure significantly prior to the traditional definition of failure. Prognostic health management (PHM) is a useful tool for assessment of the remaining life of electrical components, and is demonstrated for electrical connectors in this paper. The ability to predict the remaining useful life of a connector can benefit operators with the knowledge of when to schedule preventative maintenance, aid in the cost optimization of operations and products and increase safety by providing advanced warning of potential critical failures. The presented approach can be used for assessment of damage accrual in connectors systems in the pre-failure space and prognosticate remaining useful life. Impending failure can be identified prior to both intermittent and catastrophic failure. Repeatability of the setup and the robustness of the unique PHM prediction algorithms have been quantified.