Buckling performance of egg-shaped shells fabricated through free hydroforming

This study investigated the performance and external pressure-supporting capacities of egg-shaped shells fabricated through free hydroforming. Nine preforms (length: 256 mm; width: 178 mm) were fabricated from thin-walled stainless plates (nominal thickness: 0.86 mm), eight of which were internally bulged into egg-shaped shells at various hydroforming pressure levels. Their geometric properties were optically and ultrasonically measured before and after hydroforming. Subsequently, all samples were hydrostatically destroyed through pressurization to evaluate their ultimate strength and destruction modes. Internal hydroforming and external pressurization were numerically (nonlinear) assessed. The experimental and numerical observations were consistent. The shells exhibited adequate external pressure-supporting capacities.

Automated summary

This study investigated the performance and external pressure-supporting capacities of egg-shaped shells fabricated through free hydroforming. Experimental and numerical evaluations revealed that the shells exhibited adequate external pressure-supporting capacities. Overall, the research demonstrates the feasibility and effectiveness of using free hydroforming to create egg-shaped shells with desired properties.