Development And Application Of Stress Measurement Device And Safety Evaluation Expert System Of Transmission Tower In Service

The safe and stable operation of power grid is an important issue of the people's livelihood and national security.As the important facility of the grid system,the safe and reliable operation of the transmission tower is an important guarantee.The transmission tower sustains wind loads and other loads during service,which leads to the fatigue damage of materials.The transmission tower will be easy to collapse due to the accumulation of fatigue damage.So it is of significance to detect the real-time stress and assess the fatigue life of the transmission tower in service.In this paper,the static analysis of a typical transmission tower has been conducted,to determine the stress concentration areas of the tower.A stress real-time detection system based on FBG sensor has been designed and used to measure and detect the real-time stress of transmission tower.he stress measurement system which can achieve the real-time measurement and storage of stress,and the data measured will be sent to a specified receiving terminal via radio signals at the same time once the data exceeds the threshold value.The nominal stress approach and fracture mechanics are determined to use to assess the fatigue life of the transmission tower,through the analysis of different fatigue life assessment methods.The statistical analysis of measured stress have been conducted by rain-flow counting method to get the fatigue loading spectrum of transmission tower,namely the value cumulative frequency curve,and then the fatigue loading spectrum of the expert system has been weaved.The mechanical property test have been conducted to get the yield strength,fracture toughness and fatigue S-N curve of the Q345 steel,which is the tower material,and then the data base of material property of the expert system has been weaved.The fatigue assessment expect system of transmission tower,based on nominal stress approach and fracture mechanics,has been developed using C# programming language,and can realize the fatigue life assessment of the transmission tower in service.