Cable Length Error Analysis And Structural Redundancy Evaluation Of Cable-struct System Based On Redundancy Theory

The redundancy of Structural is an important evaluation index that indirectly reflects the overall robustness of complex structural systems.It is often associated with structural vulnerability,error sensitivity and component importance.Researchers have done a lot of research and application on traditional rigid structures based on the redundancy theory.However,the research on the redundancy of long-span special structures,especially the cable-memeber system,is only in its infancy.The cable rod system is a flexible structural system that provides rigidity by prestressing.In this type of system,the structural form is closely related to the prestressing and complementing each other.The amount of change in the length of the cable will affect the prestressing of each component in the cable rod system.Value,which in turn affects structural performance.In the initial manufacturing and later construction,various error factors cannot be avoided.Therefore,the research on the cable length error of the cable system and the evaluation of the structural redundancy characteristics based on the redundancy theory are of great significance for the design,manufacturing and construction of the cable system..The main work of this article includes the following three parts:(1)Starting from the redundancy theory of the cable-rope system,the sensitivity coefficient of cable length error and the global sensitivity coefficient of cable-length error are deduced,and the influence of the cable length error on the deviation of the overall prestress level of the cable-rope system is revealed.Global error-sensitive components and local error-sensitive components are defined,and the differences between the effects of the two types of components on the overall prestressing level of the system are compared.The error sensitivity coefficient analysis method of the traditional ribbed annular cable dome was carried out using the calculation method of the error sensitivity coefficient of the cable rod system based on the redundancy theory,and the feasibility and practicability of this method were verified by the orthogonal test method.Further,the M-shaped tensioned integral ring and the traditional rib-shaped cable dome were combined to form a self-balancing cable dome.The sensitivity of cable length errors of various components in the traditional cable dome and the self-balancing cable dome was compared and studied.The research results show that the self-balancing dome of the self-balancing cable dome with the tensioned integral ring has a certain degree of reduced cable length error sensitivity,which indicates that the self-balancing dome has the same cable length error in the construction of the structure.Compared with the traditional cable dome,it has better tolerance and adaptability.(2)Considering the stress characteristics of the cable-rope system and the definition of the limit state of the structure,three types of failures of the cable-rope system are proposed:strength failure,relaxation failure and deformation failure.Combining reliability standards,the cable-rope system under different failure forms is constructed.Critical state equation.Based on the redundancy theory,the cable length error-internal force influence coefficient matrix and the cable length error-node displacement influence coefficient matrix are derived.Finally,the initial manufacturing error of the cable rod system is obtained by solving the multi-objective non-linear programming problem.By using the above method,the initial manufacturing error control limit of the cable-rope system can be determined more completely when the initial geometric topology and member information of the cable-rope system are known.This method takes into account the reliability requirements of the cable rod system,the accuracy requirements of manufacturing and processing,and the cost requirements,and can provide a scientific basis for the fabrication and processing of cable rod system structural components.The initial cable length error control limit of the ribbed annular cable dome was calculated using the method of determining the cable length error limit based on the redundancy and reliability theory,and compared with the standard error limit.The results show that the actual manufacturing It is necessary to improve the manufacturing accuracy of the cable and strictly limit the initial error control limit of the cable length,so as to reduce the probability of possible relaxation failure and deformation failure.Finally,the initial error control limits of the cable lengths of each member of the two structures of the rib-annular cable dome and the self-balancing cable dome were found.It further shows that the self-balancing dome has better tolerance and adaptability to the initial manufacturing error of the structure than the traditional cable dome(3)Based on the static and indeterminate redundancy theory of the cable-roof system,a set of indicators for the redundancy of the cable-roof system has been formed by examining a series of indicators such as the linear and nonlinear redundancy of the structure,the redundant distribution of the components,and the redundancy balance.The structure evaluation system provides a new idea for the evaluation of the cable structure.The redundancy characteristics of two new types of tensioned integral rings of X-type and M-type are studied.The finite element analysis is used to compare the annular stiffness of the two types of annular tensioned members under the same conditions.In the case of different redundancy equilibriums,it is found that the structure with better redundancy equilibrium has larger circumferential stiffness.Then,the differences between the linear and non-linear redundancy index,the redundant distribution of components,and the redundancy equilibrium of the self-balancing cable dome and the traditional cable dome were examined.The displacement responses and internal force of the components under the same conditions and load were compared.Variety.The results show that the self-balanced cable dome has improved redundancy and balance compared with the traditional cable dome.Under the same static load,the self-balanced cab le dome has smaller node displacement and component stress.Potential for large loads.