Belief reliability modeling and its accelerated model verification design method: a case for the three-grid ion thruster

Reliability modeling for long-life complex aerospace products is important in engineering practice, especially for their design, production, and usage. However, the model verification by testing is generally difficult to conduct due to the long lifetime of the products. In this work, the belief reliability modeling and its accelerated model verification design method is proposed, and a case of the three-grid ion thruster for deep space exploration is studied. For the belief reliability modeling, the physical models of the thrusters considering performance degradation and multi-source epistemic uncertainties are constructed, integrating multidisciplinary knowledge. Further, a controlled-accelerated degradation testing can be rationally designed to verify the established models in a shortened duration. Finally, the illustration of the three-grid ion thruster shows the feasibility of the proposed method.