Dynamic response analysis of subsea electric actuator considering physical constraints of structural uncertainty

A novel subsea electric actuator is designed to drive and control valves, such as subsurface safety valves, in subsea environments. Given its harsh operating conditions and high reliability requirements, it is essential to analyze the actuator's dynamic response under stochastic disturbances to manage structural uncertainty parameters and guide structural optimization. To address this, a parameter distribution analysis method that considers physical constraints of uncertain parameters in dynamic response analysis is proposed. A dynamic model of gear meshing and shaft transmission under multi-source uncertainties is established to evaluate structural uncertainty parameters and their mutual constraints. The actuator's dynamic response under various stochastic disturbances is analyzed, including the influence patterns of uncertainty parameters on the response. Additionally, vulnerable structural components under stochastic disturbances are investigated. The main innovation of this study is to construct the feasible-set construction via physical constraints before uncertainty propagation. The proposed method offers advantages for uncertainty analysis in complex engineering structures, particularly when numerous uncertain parameters exhibit significant physical correlations. It enables detailed description of uncertain parameter distribution intervals based on mutual constraints between structural parameters, thereby preventing impractical parameter combinations in engineering applications.