Robust optimization design for sealing performance of globe-cone joint considering manufacturing and assembly uncertainties

Globe-cone joint as a common connection form is the weakness to cause leakage in pipeline system of satellite or rocket product. Manufacturing and assembly uncertainties exist extensively, which causes the uncertainty of sealing performance inevitably and thus decreases the reliability of pipeline system under harsh environment. This study proposes a novel method for the robust optimization design of key structural sizes in globe-cone joint considering manufacturing and assembly uncertainties. First, an accurate three-dimensional finite element model of globe-cone joint is built, including size error and surface micro-topography. Based on assembly simulation, it is convenient to achieve sufficient sample data. Second, the second-order polynomial response surface model is built for establishing the relationship between uncertain parameters, optimized structural parameters, and sealing performance. Third, the combination of the interval possibility method, penalty function method and improved particle swarm optimization algorithm are proposed to optimize the structural parameters including cone angle and spherical radius for improving the robustness of sealing performance. The experimental results based on simulation indicated that not only the globe-cone joints with the optimized cone angle and spherical radius had the better sealing performance, but also the sensibility of sealing performance to various manufacturing and assembly uncertainties was greatly decreased.