Fig. 1. ϕ865 mm cylinder with inner cross bars

Fig. 2. Size of the tensile sample （unit：mm）

Fig. 3. Picture of the tensile testing machine

Fig. 4. Finite element model of flow spinning forming for the cylinder with inner cross bars

Fig. 5. Equivalent plastic strain

Fig. 6. Depressions and cracks on the outer side of the cross bars

Fig. 7. Influence of staggered spinning on the filling of inner bars

Fig. 8. Variation of the filling degree of inner bars along the axial direction

Fig. 9. Influence of wheel number on the filling degree of inner bars

Fig. 10. Influence of wheel number on the diameter deviation

Fig. 11. Composite mandrel with a gridded cylinder

Fig. 12. Flowchart of the spinning process for cylinders with inner cross bars

Fig. 13. Single pass spinning forming under large pressure and small feed ratio

Fig. 14. Part and dimension inspection after spinning forming（ϕ865 mm）

Fig. 15. Spinning forming of a large-diameter cylinder with inner cross bars

Fig. 16. Cylinder diameter of ϕ3 350 mm with inner cross bars

Fig. 17. Common defects of inner cross bars and well formed inner cross bars

Fig. 18. Cylinder with inner cross bars