| It is a high potential technique to identify those damaged cables from all supporting cables of a cable-supported structure (especially the large-scale cable-supported structures, such as cable-supported bridges). Now it is widely used to evaluate the health of supporting cables by monitoring their cable forces in the area of structural health monitoring. Change of a single cable's cable force has a specific and monotone relationship with damage degree of its own. However, when the cable is one cable of all supporting cables of a cable-supported structure, change of the cable's cable force seem does not have a specific and monotone relationship with damage degree of its own, because its cable force is influenced by damage degree of itself and other cables. Change of its cable force is ruleless apparently even when the cable's health state does not change at all, but health state of other cables is changing. In fact, cable force of a health cable can be observed to be increased after an observation of decrease. This situation is a big drawback for health monitoring of cables. To have a reliable monitoring and evaluating of structural health state of a cable-supported structure, cable-supported bridge for example, a reliable relationship between change of cable force of every supporting cable and health state of all cables must be established firstly, then the health evaluation of all cables can be trusted based on the relationship.For health monitoring of all cables of cable-supported structures, a series of method is introduced and investigated in the present thesis. Jianfeng Bridge (a cable-supported bridge) is selected as a case study to introduce the created health monitoring technique for all cables of Jianfen Bridge. A set of health monitoring method for all cables of cable-supported structure is introduced based on the case study of Jianfen Bridge.The main works and novel research performed in this dissertation include 4 parts:â‘ Numerical analysis method, such as finite element method (FEM), is used for analyzing mechanical properties of large-scale structures, instead of direct solution of those mechanical functions which describe the structure's mechanical relationship. In fact, FEM is usually used to analyze the relationship between changes of cable forces of all cables of a cable-supported structure too. In the first part of this thesis, a finite element (FE) baseline model of a cable-supported bridge, Jianfen Bridge, is introduced firstly. Secondly, change of cable forces of one hundred and four supporting cables are calculated through FE simulation method based on the FE baseline model of the bridge when some supporting cables are appointed to be damaged at the same or different degree. All the FE simulation cases (database) include those situations when only one, two, three, five, six, seven, thirteen, twenty-four, twenty-six, thirty-two, thirty-nine, forty-eight, fifty-two, fifty-six and one hundred and four cables are appointed to be damaged. Thirdly, state of the change of supporting cables'cable forces is analyzed to find some potential rules that might be helpful for identification of damaged cables based on the FE simulation database and SHM technique. It is firstly definitely pointed out that the identification results of damaged cables are quite potentially unreliable, if the identification just based on increasing the amount of simulation cases and lingual description of the database of the simulation cases.â‘¡In the second part, a novel linear relationship hypothesis, about changes of cable forces of all supporting cables for the health monitoring of Jianfeng Bridge, is introduced and tested based on the database illustrated in the first part. Firstly, A linear relationship function is defined by vectors and matrix, which are defined. Especially, a novel matrix which describes changes of all supporting cables'cable forces due to unit damage, is defined. The process and methods to establish the defined vectors and matrix is given too. Then, based on FE simulation results got in the first part of this thesis, processes for assessment of the introduced lineal relationship is described and error vector is defined in this part for convenient of assessing the lineal relationship. Finally, the linear relationship hypothesis is tested based on the database illustrated in the first part of the present thesis.â‘¢It is found in the second part of this thesis, the linear relationship hypothesis is acceptable when damage degree of all damaged cables is not bigger than 30% and amount of damaged cables is not too large. On the other hand, we can say that the linear relationship hypothesis is not perfect and has error so that the linear relationship function can not be solved directly to get damage degree vector of all cables; if the function is solved directly, then some unacceptable negative damage degree might got. To get an acceptable solution of damage degree vector of all cables, multi-objective optimization arithmetic is used to solve the linear relationship function in this part. The solution process is described in detail. The solved damage degree vector of all cables can describe the damaged supporting cables, both the position and damage degree. Then the introduced method is tested based on the finite element simulated results of the two pre-parts. It is found that t the introduced method to identify damaged cables of Jianfen Bridge is very effective in some degree.â‘£The preconditions for the linear relationship hypothesis and the actual application of the processes for identification of damaged cables, developed in this thesis, include that structural material is lineal elasticity and structural deformation is not too large. Finally, general, essential and compact processes of identification of damaged cables of cable-supported structures, based on the method developed for Jianfeng Bridge, are given for convenient of its actual application for health monitoring of all cables of other cable-supported structures.
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