Numerical and experimental investigation on forming stacer using compositing stretch and press bending process

A continuous cold forming method, named compositing stretch and press bending (CSPB), is an effective process to manufacture a stacer, which is a typical cylinder element with a thin strip for deployable booms in various spacecraft missions. The forming tools in CSPB are a pair of punch and die; a stacer is formed continuously by pulling the strip from the gap between the tools. The process of compositing stretch and press bending is introduced, and the forward bending and the reverse bending occur during this process. The stability of cold forming workpieces has been increased due to those processes above. In this paper, the forming process is analyzed by the numerical simulation and experimental method. The key process parameters such as post tension, die gap, punch radius, and strip thickness are studied. The macromorphology of the stacer formed by CSPB is measured and analyzed. And, the deploying force and the bending stiffness of the stacer under different treatments are investigated. The results show that the simulation results and the experimental results are in good conformity, and a stacer with good forming precision and performance can be obtained by the CSPB process without any other stabilization treatments.