FE Simulation on Superplastic Forming of Propellant Tank Dome

In the current study, a feasibility study on fabricating propellant tank dome by superplastic forming process has been carried out. Due to the size, most of propellant tank domes of large launch vehicles have been being manufacutured by spin forming using large blank sheets, creep age forming or stretch forming of gore panels which are assembled by welding. Although superplastic forming process is one of key technology to manufacture aerospace components, it is difficult to find an example that tank dome was manufactured by SPF process because of its relatively high tooling cost, equipment complexity, and capacity limit. Thus, in the current study, finite element simulation is carried out to investigate propellant tank dome forming using SPF process. Through the simulation, forming process and tool geometry are designed and discussions and some considerations are suggested in the point of view of forming equipment and tooling to realize the implementation of SPF process to propellant tank dome manufacturing.