Sequential Reliability Analysis for the Adjusting Mechanism of Tail Nozzle Considering Wear Degradation

The adjusting mechanism is an important part of an aero engine, and the wear degradation of clearance is widely present in its hinges. In this work, an adjusting mechanism with hinge clearance is analyzed by dynamic simulation and the wear depth is predicted precisely using a wear model. Based on that, a sequential reliability analysis of motion accuracy is carried out. In order to avoid the expensive computational cost of simulation, the adaptive radial-based importance sampling method combined with the adaptive Kriging model (AK-ARBIS) is employed, which describes the decrease of reliability in the standard normal space sphere by sphere with the updated Kriging model. To further utilize the information about each state of wear degradation, the advanced AK-ARBIS method is investigated. Through analytical examples of two typical mechanisms and the engineering application of the adjustment mechanism, the results show that the calculation cost of the sequential reliability analysis under different states can be effectively reduced.