A Two-Step Marginal-Restraint Mandrel-Free Spinning Method for Accuracy in Forming Large, Special-Shaped Aluminum Alloy Tank Domes

The special-shaped tank dome of a launch vehicle is large, thin-walled, curved structure that difficult to form using the conventional center-restraint spinning method. This study proposes two-step marginal-restraint mandrel-free method for forming large domes. finite element analysis results indicate larger roller fillet radius and feed ratios lead upper convex angle minimum thickness value bottom contour. explored impact shape parameter variations on convexity transition rounding accuracy. show domes increases with while overall height decreases. accuracy adversely affected by angles smaller convexities. For accurate domes, mutual coupling influence during should be considered, suitable process trajectory compensation parameters must carefully selected. Finally, verified 10 mm radius, 2 mm/r ratio, corresponding can achieve precise 2250 thin-walled