Thermal Cycling Test and Life Prediction of Aviation Electrical Connectors

Through the accelerated life tests and analyses, the reliability and life prediction method of aviation electrical connectors was studied under thermal cycling conditions. A thermal cycling accelerated test scheme for simulating diurnal temperature differences was proposed, including experiments and circuit designs. The strains of jacks in the period of stable high temperature during the tests were used as the main monitoring parameters indicating the performance degradation processes of aviation electrical connectors. The accelerated thermal cycling tests were carried out and the performance degradation laws of aviation electrical connectors induced by stress relaxation were analyzed. The critical strain values for the failure of aviation electrical connectors were derived theoretically. And the gray model, time series model and neural network based time series model were adopted in the life prediction of aviation electrical connectors under thermal cycling conditions. The results show that the strain decreases with the increases of the numbers of thermal cycles. And the larger the temperature differences, the more the strain reduction is, the more obviously the stress relaxation phenomenon shows, the faster the performance degrades and the shorter the service life is. The thermal cycling life is approximately exponential attenuation with the increases of temperature differences. © 2018, China Mechanical Engineering Magazine Office. All right reserved.