Mechanisms of failure and state analysis of electrical connectors in automobiles

Various degradation mechanisms can diminish the performance of electrical connectors in automobiles over time. It is crucial to gain an in-depth understanding of the failure mechanisms and their interactions, as well as to systematically analyze the failure mechanisms of connectors, assess their state of health, and predict the probability of failure in the future. This work provides a comprehensive overview of degradation mechanisms in electrical connectors, including fretting corrosion, oxidation, delamination, wear through of the protective coating, stress relaxation and plastic deformation. It focuses on mechanisms that contribute to increased contact resistance over time and proposes a unified model to explain their interactions. The study introduces a structured methodology for assessing connector health by outlining key measurement techniques and presenting an efficient approach to failure and state analysis that minimizes both testing time and sample size. This methodology is supported by analyses of connectors from long-term life tests and field-used, field-tested vehicles. Additionally, the study explores new aspects of the state analysis for accelerated testing of connectors, supported by examples from field-tested vehicles and various test methods, to predict connectors lifetime and evaluate the effectiveness of existing testing approaches.