Rigid-Flexible-Thermal Coupling Dynamic Investigation On Flexible Multi-body System

Dynamics problems considering the thermally induced rigid-flexible-thermal coupling have great application in certain engineering background,such as mechanical manufacturing, aviation, aerospace and many otherfields. Applied with thermal load, the thermal deformation is induced,which has significant influence on the rotational motion of the wholemechanism system after a period of time. Concerning thermal load, theinfluence of the deformation and the change of the rotational angle uponthe temperature field radiation angle cannot be neglected, therefore thecoupling effect of rigid body movement, elastic deformation andtemperature field should be considered. In the recent years, therigid-flexible-thermal coupling problems of the spacecraft appendageshave been paid attention to. It is important to establish a more accuratefinite element model for solving the rigid-flexible-thermal couplingproblems in engineering application. In this paper, rigid-flexible-thermalcoupling dynamic performance of flexible multibody system was investigated. Based on the theory of flexible multibody system, therigid-flexible-thermal coupling dynamic equations of three spacecraftmultibody systems were derived considering the change of the thermalboundary condition caused by elastic deformation and the change of therotational angle. Simulation of the spacecraft system applied with thermalload was used to investigate the effect of the characterized parameters onthe dynamic performance of the flexible multibody system. The mainfactors that induce the thermal fluttering and instability are analyzed.In chapter one, the previous work on rigid-flexible coupling dynamicsand thermoelatic dynamics is reviewed, and the objective of thedissertation is proposed.In chapter two, rigid-flexible-thermal coupling dynamic performanceof the Hubble Space Telescope (HST) is investigated. Based on the theoryof flexible multibody system, the rigid-flexible-thermal coupling dynamicequations of multibody system composed of the central rigid body andflexible blanket are derived considering the change of the thermalboundary condition caused by the elastic deformation. Simulation of theHubble Space Telescope applied with thermal load is used to investigatethe effect of the characterized parameters on the thermal flutter of theflexible appendages. In chapter three, the rigid-flexible-thermal coupling dynamics of thesatellite and plate multibody system is investigated. Considering thecoupling relation between the heat flux of radiation and the rotationalangle of the satellite as well as the rotational deformation of the plate, thevariational heat conduction equations are derived. Based on virtual workprinciple, the variational dynamic equations of the satellite and platemultibody system are derived. By leading into the kinematics constraintequations and using finite element method, the rigid-flexible-thermalcoupling dynamic equations of the flexible multibody system areestablished. Furthermore, the main factors that induce the fluttering andstability of the dynamic system are analyzed.In chapter four, the rigid-flexible-thermal coupling dynamicperformance of the rotating satellite and antenna multibody system isinvestigated. The influence of the radiation angle, damping coefficient andthe angular velocity on the fluttering and instability of the system isinvestigated, and the stability region is calculated.In chapter five, the research work is summarized and the conclusion isobtained.