Research On Storage Accelerated Test And Life Prediction For Aerospace Relay

Aerospace Relay is widely used in weapons systems. The weapon has a long-termstorage, but for single use. Therefore, prodicting relay storage life correctly hasimportant theoretical significance and practical value for normal use of the militaryequipment. Currently, the storage acceleration test failure data are often difficult toobtain, conventional methods can not used to evaluate the shelf life. To solve thisproblem, based on the relay storage failure mechanism analysis, this paper study theaerospace relay accelerated test methods and storage life prediction methods.Currently, measured parameters are often selected from the general parameters, andnot necessarily sensitive of accelerated stress. In this paper, the main aerospace relaystorage failure mechanisms are analyzed. From contact corrosion film and stressrelaxation mechanism, relay failures parameters are determined. Using ion diffusiontheory, contact resistance storage degradation model is established. The reaction offorce and the pick-up time is determined by experimental and simulation method, andpick-up time storage degradation model is established. These provide theoretical basisfor the test plan and the storage life predicton.Aerospace Relay’s storage accelerated test plan, including the test’s type, the typeand level of accelerated stress, the number of samples, the monitored parameters and thetest conditions, is designed. Storage performance degradation data is got throughstorage acceleration test. The parameters selection is verified to be correct through trendanalysis and correlation analysis.Storage Aerospace relay performance degradation is slow, and analyzing thedegradation process can reveal the storage degradation. In this paper, storage lifeprediction method based on degraded data is studied. We use wavelet theory and timeseries stationary test method to pretreat the test data. The degradation fitting model isestablished. Each relay’s pseudo life is extrapolated. Weibull-Arrhenius accelerationmodel is established to estimate storage life under normal stress. Using stochasticprocess method, the failure distribution model is established. And storage life pointestimates and confidence intervals under each temperature can be calculated.Finally, Aerospace relay storage acceleration test measurement system is designedand developed. AC excitation improved four-line method and the two side pair methodare used to improve contact resistance measurement accuracy under small current. Pick-up time measurement circuit is designed belonged to the standard. Using the switchingboard, large sample is test by order polling way. The system software is written usingVC++. The performance regular automatic high precision measurement and analysis of degradation parameters are achieved.