Abstract:

：Triaxial air bearing testbed, a core sophisticated equipment for physical simulation of spacecraft, are used widely. The unbanlanced torque caused by elastic deformation and self weight of the testbed is an key index of work ability. To evaluate the unbanlanced torque and optimize the design of the proceeding “5 000 kg triaxial air bearing testbed”, a theoretical model is presented, by which 3 basic deformation parameters are defined to describe the offset of the mass center. With the help of numerical simulation and theoretical analysis, 2 optimization questions are raised and the optimum upward shifts of the mass center are specially advised to reduce the unbanlanced torque. It’s not difficult for testbed design to make the unbanlanced torque during the small swing, e.g. 0.3°, approach zero, while the most challenging task is to minimize the unbanlanced torque during the 15° bias from the initial attitude. Moreover, the tendency of optimum parameters are concluded, which can be adopted as an useful advice for the design and levelling of the air bearing testbed.

Key words: structural deformation, the offset of the mass center, the optimum design, triaxial air bearing testbed