Application Of Shape Memory Alloy In The Large Deployable Antenna On Satellite

The large deployable antenna in satellites has high flexibility and strong sensitivity to temperature. Antenna always enters into and leaves the earth shadow periodically when it orbits the earth, and it is affected by the shadows of itself. So the structure will induce larger thermal deformation. So, it is very important to control the thermal deformation of antenna at orbit.The main research object in this paper is to use characteristic of Shape Memory Alloys(SMA) to control the thermal deformation of the deployable antenna at orbit. The content of this paper can be divided into four parts as follows. Firstly, stress-temperature relation and the Young's modulus changing with temperature of alloys which are simulated by program Matlab for Brinson constitutive law. Secondly, the temperature and deformation of the deployable antenna are calculated at different site with finite element program ANSYS and the theory of thermal elasticity. Thirdly, in order to let the complex models which embedded into SMA simple calculate. The fractional computation and handing with the load finite mechanics models are put forward. And the feasibility of this method is proved through using a simple example. Finally, the stress of the antenna and the RMS of the reflecting face are calculated with ANSYS for the deployable antenna which embedded into different number of NiTi Shape Memory Alloys and at the different site. According to the discussion in the paper, the RMS of the deployable antenna which the SMA are integrated into is diminished. So, SMA are embedded in the deployable antenna can control its precision.