The Conformation Theories Of Tensility Structures And The Structure Analysis Of Flexible Antennae

Tensility structures, cable antenna and inflatable antenna are all flexible structures. Flexible structure becomes a structure, just because prestress has been applied. Form conformation and force-finding of flexible structures are main direction of this dissertation. This paper mainly consists of five content: form-finding analysis of tensility structures; form and tension analysis of the cable in tensility structures; force-finding analysis of membrane structures; tension optimization analysis and surface deviation analysis of cable antenna; parameter analysis and load analysis of inflatable antenna.Form-finding analysis is one of the most important contents about the conformation theories of tensility structures. This paper systematically reviewed dynamic relaxation method, force density method and nonlinear finite element method. And their improved methods were also researched, for example the force density method with the triangle element transformed the three links, surface stress density method, surface stress density method of sub-structure and nonlinear finite element method of little young's modulus. Through the analysis of classic example and engineering example, their merit and defect were discovered, and the solutions were found. This content is the base of the paper. Combined the curve theory of differential geometry and the cable model applied distributed load, form analysis and tension analysis of boundary cable, ridge cable and valley cable were performed. Then the internal relations between the prestress of membrane, pretension of cable and cable form were found. On the base of above research, the force density method with modified boundary cable and nonlinear finite element method of little young's modulus considered boundary cable were brought forward.The mean of force-finding analysis is how to calculate self-balance prestress of the structures. Used the bending-free theory, analytic formulae between the self-balance prestress and the form were deduced. Based on the similarity principle and nonlinear finite element method, reposition balance method was put forward to find the prestress. And this method was optimized by means of the relationship of the element on membrane curved face. We can use optimized reposition balance method to analyze and optimize the self-balance prestress of curved face found by force density method and nonlinear finite element method of little young's modulus. At last the vista referred, which is about how to make use of force-finding theory to measure the self-balance prestress of founded membrane structures.The self-balance pretension of cable net on Astromesh deployable antenna need be calculated and optimized according to force-finding theory. So the optimized reposition balance method used to calculate cable net was deduced. After the pretension of four different cable antennae had been optimized, the character of their pretension was defined and their merit and defect were discovered. The questions were all discussed, which are about the relationship between layout of cable and...