Multi-stage hydroforming method for conical thin-walled parts

Taking certain types of conical aviation engine cowling as cases, the variation of latitude direction strain during the hydro-mechanical deep drawing was analyzed qualitatively. The method of multi-stage forming process was adopted to solve the bottom rupture and suspended area wrinkles of the conical parts. The middle configuration influence on suspended area wrinkles, wrinkling regional distribution and wall thickness distribution was investigated by combining the numerical simulation and experimental verification. The optimized parameters of the intermediate configuration forming process were determined. Finally, the parts with less thinning rate and good surface quality were formed successfully.