Dynamic Theory Analysis, Simulation And Experiments For Deployment Process Of Deployable Space Structures

As a new kind of structure, the deployable structure is more and more widely used in the fields of astronautics, building structure and military engineering, etc. It can be divided into deployable space structures and deployable ground structures. Based on some projects, dynamic theory analysis, simulation and experiments had been studied systematically for the deployment process of deployable space structures in this dissertation.Firstly, after referring a lot of pertinent literature worldwidely, the application of deployable space structure and the research actuality of its deployment process were summarized, the research significance and approaches were presented.Afterward, this dissertation described the theoretical basis employed to analyze the deployment process of deployable space structures. As a significant theory to analyze the deployment analysis, the Moore-Penrose generalized inverse matrix theory's definition, solving method, character and application were introduced detailedly. The kinetics relation and the quasi-static shape analysis of deployable structures were presented, and the influence of the geometric restriction's higher order items to the deployment analysis accuracy was discussed.The circular truss deployable antenna has attracted more and more attention in some countries for its small package volume and light weight. For the sake of the dynamic analysis of its deployment process, a small proportional circular truss deployable antenna model was made, the designing of which was introduced simply: the moveable component design, the rod and driving cable design, and the supporting cable net design etc., and the deploying and stowing mechanism was explained completely. Dynamic equations of the structure were formulated with the idealized truss joints as variables in the Cartesian coordinates. Using the null space orthogonal basis vectors of the constraint equations' Jacobian matrices, a set of quasi- velocity was integrated into the dynamic equations, then a group of independent dynamic equations with no coefficients were formulated. The deployment process was analyzed by combining the generalized inverse matrix and multi-body dynamics theory. The most attention was paid to the following: the formulation and solving method of dynamic equations of a constrained multi-body system, the deployment dynamic analysis with Coulomb friction, the formulation of kinematic constraint equations and the Jacobian matrix, the discussion of the Jacobian matrix, and the active correction of constraint violation and so on. So the numerical values of everycharacteristic parameters during structural deployment process were obtained, which could be an effective reference to the structural design and optimization.This dissertation introduced the structure design of a tetrahedral truss modular deployable antenna driven by torsional springs model briefly, and the shape topology of the deployed state and stowed state was also introduced. The dynamic equations of the deployable structure driven by torsional springs were deduced, which could reflect the variable driving force during deployment. According to the deploying and stowing mechanism of the structure, a new mathematic algorithm was developed to formulate the kinetic constraint equations and relevant Jacobian matrices, and the unilateral kinematic constraints of deployment were specifically solved by adopting a forcast-lock method, whose procedure flow chart was presented. Considering the actual movement of the structure, the influence of viscous friction damping to the structure deployment was analyzed. This dissertation presented the calculation method of the grid paraboloid antenna' reflector accuracy which could be used to forecast the influence of different torsional springs stiffness and structure design to the deployment reliability. Moreover, the minimal stiffness of the torsional springs needed to deploy the structure was discussed.Deployment analysis of deployable truss structures with flexible deformation was discussed. Based on the kinetics relation and equilibrium equation of the structure, a new hybrid method was developed to analyze deployable truss structures with mechanism motion and flexible deformation by using the generalized inverse matrix theory, and the coupling between these two motions was calculated.The geometry shape of deployable spatial shell structure can be approximated by many plane triangle elements when the elements are small enough. The triangular shell element was described using two sides and the relevant angle, the kinematics relation and the basal equation used to solve rigid body displacement of the structure was presented, then the moving process of the structure under applied loads was analyzed by using the generalized inverse matrix theory and multi-body dynamics theory. This dissertation had also derived the kinematics relation and the basal equation used to solve rigid body displacement of a quadrangle element which is widely used to divide the structure. The approximate method was presented to analyze the flexible deformation of the structure during deployment, and the efficiency of the method was verified by simulation program based on it.According to the research above, the method of developing its deployment dynamic simulation software with self graphic platform was presented in detail in thisdissertation, some key technologies during developing process such as the system frame, the data structure, the constitution and arrangement of class, the development principle of core analysis module, and the procedure of visualization were included. Then by using VC++, MATLAB and OpenGL mixed programme technology, a deployment dynamic simulation software (DSDSP) was developed, whose validity of analytical process, completeness of its basic function, properness of its mistake disposing and convenientness of its operation were verified by some tests using different deployable structure design data and comparing them with the ADAMS analyses and theoretics solution.After studying the theory analysis and simulation software, the dynamic experiment method of deployment process for deployable truss antenna was discussed. The stiffness and initial angle of torsional springs were tested. With a small proportional deployable truss antenna model, this dissertation fulfilled the deployment process experiment, introduced the relevant experiment equipments, discussed the different experiment schemes, gathered the impulse acceleration of measure nodes during movement, compared the experiment result and the analytical result using the simulation software, and analyzed the reason of difference.