A Novel Deployable Reflector using a Lazy Tong Truss


In this paper, a new concept for a deployable parabolic reflector used in SARsatellite has a support based on a two-dimensional lazy tong mechanism isproposed. Two sets of lazy tong mechanisms are used, one at each side, to supportthe structure through its operation (deploying and folding). The deployment of thestructure is controlled by the vertical inward movement of the ends of the first twobars in each mechanism. This movement is directed by the strain energy stored inthe helical springs that work at those places. A preliminary design of the quarterscale model of the suggested reflector in deployed configuration is modeled andanalyzed using ANSYS software program. The value of the maximum deflectionand Von Mises stress due to effect of inertia load only are obtained for thecomposite material (T300/Hexcel 8552) of the reflective surface and hardaluminum alloys (2024-T3) of the truss. They were 0.465 mm and 23.3 MParespectively. The linear buckling behavior of the structure is as well studied. Thefirst eigenvalue factor was about 19.639. The theoretical total deploying time andvelocity is considered and their magnitudes are about 0.14 sec. and 0.46 m/srespectively. The packaging volume was about 1/6th of deploying volume. The totalestimated mass of this quarter scale reflector was approximately 2.5 kg.