Shape Analysis For Antenna With Constraint Of Homologous Deformation And Experiment, Clearance Analysis For Deployable Structure

Following the developing of the antenna technology, How to control the antenna' reflector accuracy, How to analyze clearance of the joint in the deployable structure, and How to simulate movement process of deployable space structures have become the focal point. Based on these question, The research content of this dissertation is divided into three main part:1) shape Analysis for truss structures with the Nonlinear Constraint of homologous deformation;2) dynamics numerical analysis of deployable space structure with three-dimensional clearance revolute joint;3) tensile test of the driving cable and deployment process simulation of the circular truss deployable antenna.Firstly, after referring a lot of pertinent literature world widely, the background of the three questions above was expounded. And the research actuality of the three questions above were summarized, the research significance and approaches were presented.Afterward, As a significant theory used in the following part of this dissertation, the Moore-Penrose generalized inverse matrix theory's definition, solving method, character and application were introduced detailed. The formulation is presented for the first order derivation of AA~+ (A is a matix,A~+ is the generalized inverse matrix of A)to its variables in order to solve the nonlinear equation in the following part of this dissertation.This dissertation deals with the shape analysis for truss structures with the nonlinear constraint conditions of homologous deformation .Based on the Best Fitting Parabloid.the constraint conditions of nonlinear homologous deformation was prenstend.The nodal coordinates of structure can be divided into two groups: nodal coordinates under nonlinear constraint conditions of homologous deformation, and free nodal coordinates. Then the existence condition of solution for basic equation, which includes the constraint conditions of nonlinear homologous deformation, is expressed as a set of nonlinear equations with variables of nodal coordinates under nonlinear constraint conditions of homologous deformation. After the solution of the nonlinear equations by generalized Newton-Raphson method, the final shape is found out .The validity of the proposed method is verified by numerical examples concerned with space truss.Clearance in the joint is used to keep running fit of the joint in the deployable structure, and is unavoidable, but the clearance also results in wear, loss of performance, noise, and vibration. The clearance in the joint is a complex and important issue in the precision space deployable structure. The work of analysis of clearance in the deployable structure is supported by the national defense "973" project. In this dissertation both radical and longitudinal clearance in the revolute joint of the space deployable structure were considered. With the analytical define of the least distance between pin and journal in the radical and longitudinal direction of the pin , the discriminant equation was formulated which decided contact and separation between pin and journal in the three-dimensional clearance joints, the normal contact force between journal and pin was modeled by a nonlinear elastic-damper model, then divided the movement process into "contact" and "separation" to found the dynamic equation of the multi-body system .Based on the numerical analysis of the deployable truss ,the influence of three-dimensional clearance on the movement process was analyzed.For its small package volume, light weight, and high success rate of deployment, the circular truss deployable antenna has attracted more and more attention. The work of tensile test of the driving cable and deployment process simulation of the circular truss deployable antenna is supported by a national defense project. The designing of the circular truss deployable antenna was introduced simply, and the deploying and stowing mechanism was explained completely. For presenting the accurate tension of the driving rod used in the simulation of deployment process, a device was designed to measure the tension of the driving rod in the whole deployment process. The designing and working principle of the device was illustrated. The tensile test process was explained. The dynamic strain of the device recorded by the dynamic strain indicator in the test was prensented.Based on the test result, the tension of the driving rod was calculated. Error analysis of test was made.Based on the tension of driving rod in the deployment process from the test abve,the deployment process in the deployment ground test was simulated using ADAMS : the three-dimensional model of the circular truss deployable antenna was built up in ADAMS/View. All the constraint conditions was considered in the model, including the revolute joint, the translation joint, the synchromesh gear and the constraint applied by the zero gravity instrument. Both the driving force of the driving rod and the force of the torsion springs were considered in the model. Form the ADAMS/ postprocess, the numerical values of every characteristic parameter during the deployment process were obtained, the asynchronous deployment was simulated by considering the decaying of the driving rod tension and the failure of the synchromesh gear. The reason of the asynchronous deployment was analyzed. Theseresult from the simulation could be an effective reference to the structural design andoptimization.