Research on forming and mechanical properties for one dimensional linear deployable boom Stacer of spacecraft

As the core component of long-distance telescopic driving device, Stacer with its unique advantages plays a vital role in aerospace. In recent years, more than 700 Stacers have been used in space missions. However, its complex nonlinear structure leads to forming difficulties. In this paper, a new method named continuous stretch bending is applied to produce Stacer. The forming process of stacer is studied by the numerical simulation. It shows that the forward and reverse bending occur during the forming process. The residual stress of cold forming stacer has been released or made tending to the favorable direction without any heat treatment. Then Stacers are produced under different key forming parameters. Their mechanical properties variations are analyzed. The ranges of the optimal parameters obtained in this study are as follows: the strip width is 115-130 mm, the natural diameter is 16-26 mm and the natural helix angle is 55-65 degrees. At this time, Stacer can be deployed smoothly and the directivity angles of Stacer are less than 1.0 degrees. The bending stiffness of Stacer is similar to that of the thin-walled tube with the equivalent wall thickness. Sound Stacers with good mechanical properties are obtained by the continuous stretch bending.