Research On Measurement Method And Divice Of Cable Force Based On Elastic Deformation

Cable-stayed bridge and suspension bridge, which are most widely used inlong-span bridges, make up a large proportion in large and major bridges. The safetyand health problems of bridge are very critical. In this kind of large and extra-typebridge, the cable is a core component of the bridge which used to bear the load. Cable isan important component, and cable health directly affects the internal force distributionof bridge structure, linear structure and the overall structure of security. Themeasurement of the cable-stayed stress state is an important indicator to measure thebridge cable whether in the safe operation. The traditional cable force measurementmethods have their inherent drawbacks, and they are difficult to meet the long-termonline monitoring of the cable force. Put forward a method with high measurementprecision, long life, low cost and long-term online monitoring, which is an importantissue to be solved in engineering field.This paper firstly summarizes the methods of cable tension monitoring at homeand abroad. The measurement method of cable force is put forward based on the elasticdeformation. The measuring devices are designed, and the experimental platform is setup to carry out tension experiment. Then analyze the experimental data. The specificresearch works are as follows:(1) To master the basic method and principle of large bridge cable forcemeasurement, and analyze the measurement principle of the steel cable force. Toanalyze the shortage of the current measureing methods by studying current research onsteel cable stress measurement methods, and put forward the development trend of thecable force on-line monitoring.(2) To do researches on the principle of cable force test based on Elasticdeformation effect, and design the cable force measuring device based on this principle.(3) Combined with the actual measurement requirements, design the measurementsystem according the requirements of precision, measuring range, monitoring frequency,etc.(4) To design the cable force monitoring, including hardware design andapplication program design.(5) By tension experiments on designed system, the results show that the feasibility of the new method is valid. By analyzing the experimental data, the repeatability andaccuracy are valid.The experimental data indicate that the system can measure the cable force valueand the changes of cable forces. For the test cable, the measuring range of this system isfrom0to400KN, the actual measurement frequency is1HZ. The greater the cableforce, the more accurately the measurement system and the actual measurement error isin±1%. The results meet the design requirements.