Robust Design of Electron Beam Welding Process for a Compressor Casing Outer

As a key connecting and load-bearing component of aero-engines, the process quality of the compressor casing directly determines the service life and reliability of the engine. During outer ring electron beam welding, inherent fluctuations in material and equipment parameters easily lead to excessive deformation, crack propagation, and dimensional drift caused by residual stress. Considering parameter uncertainty, this work conducts robust design to reduce welding deformation and residual stress. Firstly, five process parameters are selected to represent the five factors of process reliability (Personnel, Equipment, Materials, Process Methods, Environment). A factorial design is applied to generate simulation schemes, and welding simulations are carried out in SYSWELD to obtain samples of maximum deformation and maximum stress. Secondly, a response surface surrogate model is built via stepwise regression and validated by goodness-of-fit test and analysis of variance. Subsequently, global sensitivity analysis is performed using the Sobol method, and uncertainty quantification is implemented through Monte Carlo sampling with parameter distributions determined by equipment precision and expert experience. Finally, an equal-weight robust optimization model is solved by the particle swarm optimization algorithm. Results show that the optimized scheme significantly reduces the mean values of maximum deformation and stress while suppressing their fluctuations effectively. The proposed framework provides a systematic solution for process improvement of key aero-engine components.

Keywords: SYSWELD, Response Surface Methodology, Robust Design, Compressor Casing Outer.