Method for identifying concentrated loads of damaged cables in linear displacement process based on strain monitoring

Abstract

The invention discloses a method for identifying concentrated loads of damaged cables in the linear displacement process based on strain monitoring. The method is based on strain monitoring and includes the steps that whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring linear displacement of a support, the temperature of the cable structure and the environmental temperature, and the mechanical calculation reference model, including the linear displacement of the support, the temperature of the cable structure and the environmental temperature, of the cable structure is obtained; unit damage monitored quantity value variation matrixes are calculated based on the model; non-inferior solutions of current nominal damage vectors of evaluated objects are calculated according to current value vectors of monitored quantities, current initial value vectors of the monitored quantities, the unit damage monitored quantity value variation matrixes and approximate linear relations among the current nominal damage vectors of the evaluated objects to be gained. When the linear displacement of the support and the temperature change, the influence of interference factors can be eliminated, and concentrated load variable quantities and the damaged cables can be identified.

Description

technical field [0001] Cable-stayed bridges, suspension bridges, truss structures and other structures have one thing in common, that is, they have many parts that bear tensile loads, such as cable-stayed cables, main cables, slings, tie rods, etc. , cables, or rods that only bear tensile loads are supporting components. For the sake of convenience, this method expresses this type of structure as The rods under tension or axial compression loads (also known as two-force rods) are collectively referred to as "cable systems" for convenience, and the term "supporting cables" is used in this method to refer to bearing cables, bearing cables and A member that bears axial tension or axial compression load is sometimes referred to as a "cable", so when the word "cable" is used later, it actually refers to a two-force member for a truss structure. The damage and slack of supporting cables is a major threat to the safety of cable structures. In this method, damaged cables and slack ca...

AI Technical Summary

Problems solved by technology

[0005] When the support has a linear displacement, some of the currently disclosed technologies and methods can only identify the change of the structure's load when all other conditions remain unchanged (only the load on the structure changes), and some can only identify the change of the load on the structure under all other conditions. Recognizes changes in structural health when constant (only structural health changes) and some only recognizes structural (environmental) temperature and structural health while all other things are constant (only structural temperature and structural health change) State changes, there is currently no public and effective method that can simultaneously identify changes in structural load, structural (environment) temperature, and structural health status, or in other words, when the load on a structure and the structural (environment) temperature change simultaneously At that time, there is no effective method to identify the change of the structural health state, and the load on the structure and the structure (environment) temperature often change, so how to eliminate the load change when the load on the structure and the structure (environment) temperature change and the impact of structural temperature changes on the identification results of the health state of the cable structure, so as to accurately identify the change of the health state of the structure is an urgent problem to be solved at present. This method discloses a method that can be used in When the concentrated load on the cable structure and the structural (environmental) temperature change, the influence of the support line displacement, load change and structural temperature change on the identification results of the cable structure health status is eliminated, and the problematic cable is identified based on the monitoring of the monitored quantity. The safety of structures is of great value

[0006] Similarly, in the currently disclosed methods, there has not been a method that can eliminate the influence of support line displacement, structural temperature change, and support cable health status, so as to realize the correct identification of the degree of concentrated load change. For structures, the load It is also very important to identify changes

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