Research on reliability evaluation of aviation actuator seal based on response surface model

To address the recurrent leakage issue at the sealing interface of a specific actuator model during maintenance operations, we established a parametric two-dimensional axisymmetric finite element model of the piston sealing structure. To systematically investigate the critical factors affecting sealing reliability, we selected manufacturing tolerances, fitting clearances, and working pressure as key variables. Using response surface methodology (RSM), we developed a surrogate model for predicting O-ring contact stress characteristics. Subsequent reliability assessment based on this surrogate model revealed that insufficient contact stress constitutes a primary failure mechanism. To resolve this identified failure mode, we propose increasing the O-ring cross-sectional diameter as an effective countermeasure. Comprehensive reliability evaluation demonstrates that this design modification significantly enhances the actuator’s sealing performance, with quantitative analysis confirming a marked improvement in sealing reliability.