Optimization And Control Research Of Cable-strut Tensile Structures

The cable-strut tension structure is composed of cables and struts.Thanks to the characteristics of light and high efficient,it has become a hotspot in the field of space structure.Several topics about cable-strut tension structure have been studied in this paper.Starting from the mechanical properties of the cable-strut tension structure,the optimization method of the structure in design stage and the active control method of the structure in service stage have been studied deeply in this paper.To begin with,the structural system of the cable-strut tension structure is classified by the equilibrium matrix theory,and the initial prestress of the structure can be determined by the theory.Then,the buckling performance of struts in two kinds of cable-strut tension structural elements is analyzed by nonlinear finite element analysis software ANSYS.The effects of the initial prestressing force,the initial defect of the strut and the stiffness of the upper member on the mechanical behavior of the structural elements are taken into account in the calculation process.The whole process of structural analysis have been conducted for cable dome structure and suspendome structure.The aim of the analysis is to have a better understanding of the structural performance under full span load.The procedure of shape optimization design of cable dome is compiled by using MATLAB and ANSYS.Using the genetic algorithm and nonlinear finite element analysis software,the prestressing force,the cross section of members and the shape parameters of the cable dome can be optimized simultaneously by the program.The program can be used to achieve the goal of reducing the amount of steel for the single objective optimization and reducing the structural steel and improving structural stiffness for the multi-objective optimization.The program can be used to help the designer to determine the structural design parameters in the structural design stage.Based on the relationship between structural force and deformation,the theoretical formula of active control of cable-strut tension structure is deduced.The nonlinear force method calculation formula and the incremental relationship between shape and internal force and active control amount are obtained by nonlinear force method.The formula of calculating the internal force and displacement sensitivity of the cable-strut tension structure during the active adjustment process is deduced by force method.The control efficiency of the internal force and shape of the active control unit in different position is calculated,which can provide guidance for the selection of the active control unit.Based on the theory of nonlinear force method,the theory of shape control and force control method of cable-strut tension structure are established.The mathematical model of struc tural shape control,force control and synchronous control are established.Based on the analysis of the existence of the solution of the equation in the active control,the method of determining the number of actuators and the criterion of the arrangement of the minimum number of actuators are presented.On the basis of the theoretical analysis,the herringbone ribbed cable dome model with adjustable cable length was designed.The static experiment which consists of the full-span load test and the half-span load test.was carried out respectively.The active adjustment experiment of the different types of cable as the active unit and the active control test aiming at controlling the internal force of the structural member and the displacement of selected node were carried out.The comparison between the experimental results and the numerical results shows that the response of the structure to the length variation of the different active units is close to the theoretical results,and the active control test can achieve the expected control target.The correctness of the theory and the feasibility of the active control method in the application of the cable-strut tension structure are verified.The research work has improved and promoted the development of the mechanical performance,the optimization design and the active control of the cable-strut tension structure.It also provides the theoretical basis and the experimental verification for the engineering application of the structure.