Uncertainty analysis and multi-objective billet robust optimization for transitional region of multi-rib component under isothermal local loading forming

摘要: Isothermal local loading forming is promising to manufacture the large-scale Ti-alloy multi-rib component, but folding, die underfilling, and strain concentration (SC) are undesired characteristics existing in transitional region due reciprocating material transfer between unloading region. The current research showed that optimized billet could eliminate or improve these defects. However, it may also lead unacceptable results variation of uncertainty factors, such as manufacturing tolerance billet, fluctuation stroke length, friction factor, temperature. Aiming at this issue, an analysis multi-objective robust optimization performed based on 3D finite element simulation dual-response surface model. Firstly, a valid FE model eigenstructure established represent Then, significance factors carried out significant obtained. Subsequently, concerning mean standard deviation underfilling rate average SC zone under condition avoiding folding established. Finally, Pareto-optimal solutions obtained by NSGA-II minimum distance selection method employed acquire satisfied solution. comparison deterministic not only effectively avoided more filling deformation homogeneity can be achieved.