Study On Key Problems Of Cable-Supported Structure

The cable-supported structure is a new high efficient structural system, which is generated on the basis of summarizing the merit and demerit of cable-stayed structure and suspended structure respectively. The horizontal force of cable is effectively reduced by conducting self anchorage of the cable, for the sake of reasonable bearing force, high cable utilization, safety and economics. The cable-supported structure has some key issues, including cable-supported joint, control of pre-stressing ratio of the cable, optimization for dimension parameters of the cable-supported structure and structural wind dynamic response. In this thesis, the first two problems were mainly studied. Firstly, full-scale experimental test and finite element analysis (FEA) for the cable-supported joint are mainly studied in the research field of cable-supported structure. The mechanics performance of the joint is analyzed. Secondly, the control of pre-stressing ratio of the cable for a structure of single cable-supported truss with one stripe of cable is analyzed and the stress behavior of the whole structural system is studied under the different pre-stressing status of the cables.the main research contents in this field include:1) The joint performance differences are studied in the different contact media. From the test results, the cable performances are estimated on the variety of the contact media between the cable and the bracket, in order to propose for the contact medium choice for the real project. Furthermore, the pre-stressing friction loss and the cable slip measurement are measured and their variation processes are further studied during the test to obtain the variation rules of pre-stressing friction loss, slippage measurement and friction coefficient. Besides, the pre-stressing over-tension test is performed to estimate the effects of the number of pre-stressing over-tension and the degree of over-tension on decreasing the pre-stressing friction loss, and to provide some advices for real projects.2) In addition, nonlinear contact FEA analysis is conducted with various friction factors to study the impact factors and the theoretical basis of pre-stressing friction loss, to obtain the relationship among pre-stressing loss, slippage measurement and friction factor, and to provide the mechanics performance and the design reference for cable-supported joint combined with the experimental test results.3) The FEA model is created for a structure of single cable-supported truss with one stripe of cable. The cable-supported joint system is simply considered by coupling degrees of freedom along the friction face between the cable and the truss bracket in the normal direction. Therefore, the pre-stressing loss of the cable along the joint can be predicted in the FEA model after stressed. Furthermore, the stress behavior of the whole structural system is studied under the different pre-stressing status of the cables to obtain the variation rules of the structural deformation and the element forces respectively with the variable pre-stressing ratios of the cables, and to provide some advice for the control of pre-stressing ratio of the cable.