Dynamics Analysis Of Spatial Deployable Truss Structures

A spatial deployable truss structure was studied by the ways of multibody dynamics. The equation of multi body dynamics was set up with the Lagrange multiplier method and the dynamics simulation models of deployable truss structures were built by ADAMS and I-DEAS.Firstly, a rigid spatial deployable truss system with joint clearance was simulated with ADAMS. By comparing the ideal joint and clearance joint for the deployment process of a spatial deployable truss structure in multibody dynamics, it is found that the existence of the joint clearance makes the movement discontinuous, and also found the attitude angle degree and angle velocity of the spacecraft are affected in the deployment for the joint clearance. The contact forces in the joint increase as the same reason.Secondly, a flexible spatial deployable truss system was simulated in the combination of ADAMS and I-DEAS software. The modal neural files (MNF) derived from I-DEAS modal solution were imported into the ADAMS/FLEX. Then the flexible multi body dynamics simulations of the deployable truss system were carried on when the truss is assembled with a spacecraft. The dynamics characteristics of the truss in the moment of folded state and completely deployed state were listed.The rigid and flexible trusses were simulated respectively. The dependences of the attitude angle degree and angle velocity of the spacecraft on the rigid and flexible situation in the deployment process and drive velocities loaded on the joints were derived. The frequency-amplitude characteristic curves were gained from the attitude angle velocity curves of the deployment of the flexible truss and locked flexible truss after deployment through the Fast Fourier Transition (FFT) method.Finally, the motion stability of the flexible deployable truss mentioned before was analyzed. According to the definition of motion stability, the simulation results under the conditions of different initial attitude angle velocities and pulse torque function indicate that the deployment motion of flexible truss under these initial distortions was steady. The drive angle velocity of deployment...