The Mechanism Research For Retractable Roof Structure And Study On Wind-Induced Dynamic Response

There are two kinds of mechanism included in the research of this dissertation. One is the adjustment mechanism of the imaging lens's focal length of a space solar telescope, the other is retractable roof structure. Based on the particularities of the space mechanism, much meaningful work has been done in this paper.The work of the adjustment mechanism is a project which is supported by the state committee of "863". Based on a advance model, the space dynamic environment test has been done, and the gap element method is presented on the background of nonlinear vibration system.The effects of clearances within the connections of the mechanisms and of elastic compliance of the links and members of the device are very serious. Especially to the mechanism worked in space environments, the analysis method is important. The gap element method is proposed in the paper for two kinds of problems, which include contact problem and gap joint problem. Elasticity contact problem falls into the category of unknown boundary value problems. It follows that the contact area and contact conditions or states (sticking, sliding or clearance) can never be determined without special mathematical analysis, which is a very difficult work. The boundary conditions of the contact surfaces are deduced. According to the principle of virtual work, the finite element equations of the contact problem composed of gap elements are obtained. The calculating procedure with gap element method and the features of it are all presented. The analysis of parts of the adjustment mechanism made by our lab is given using gap element method. The application of the gap element method in gap joint mechanisms is proposed. The stiffness matrix of the rotate joint elements and sleeve joint elements with gap elements are formed and the dynamic equation of the structure is given in the paper.Retractable roof structure lets building have indoor and outdoor using functions. It is so wildly used in modern sport facilities. There are tens of retractable roof buildings constructed inthe world. They have brought about considerable social and economical benefits. These typical realized retractable roof buildings provide us with great references to further research.The research of retractable roof structures is only at the beginning in China. There are still short of systemic and theoretical guides. With the development of the economy and technology, the requirements of the retractable buildings grow rapidly. Undoubtedly, it is very urgent to do research on the subject. The key point of this research is in its mechanism.The Kalker's theory of three-dimensional elastic bodies in rolling contact with the Non-Hertzina form is employed to analyze the relationships of creep forces and creepages of retractable roof structure's running device. The relations is applied to determine the influence coefficients expressing the relations between the lateral elastic deformations of wheelset and track and the lateral unit loads on the contact areas of wheel/rail. The influence coefficients were used to revise some of the influence coefficients, and the theory of Kalker and the modified theory were respectively employed to analyze creep forces of wheelset and track. The numerical results obtained show a great influence of structures deformations of track on the creep forces.The plane stress theory is applied to analyze the contact stress between wheel and rail. The formulas for calculating contact stress and contact region width are derived. The condition of plane strain does not fulfill.The research of retractable roof structure's wind pressure and wind-induced dynamic response is also been done. The difference of wind pressure distribution between open state and close state is presented. Wind-induced dynamic response analysis with gap element is employed.