Damage Identification Of Transmission Tower Based On ARFIMA Model

The UHV transmission tower is an important hub in the construction of transmission projects and is related to the safe operation of the entire power grid.However,the transmission tower structure is exposed to the complex environment all year round,and is affected by wind,sun,earthquake,rain and snow,etc.Coupled with the inevitable structural design defects and construction errors,the structure is inevitably damaged.These damages are difficult to detect with the naked eye,and in the long run,they will cause greater safety hazards to the structure.Once the transmission tower collapses,the consequences will be unimaginable.Therefore,real-time health detection of transmission towers is of great practical significance for stabilizing social order and ensuring the safety of the people.However,there are currently few effective methods for the health detection of transmission towers.Therefore,in this paper,a global damage detection method based on the time series ARFIMA(Autoregressive Fractionally Integrated Moving Average)model is proposed.This method uses the acceleration response data of the structure as input to establish appropriate ARFIMA models.Using the cepstrum distance between ARFIMA models as damage indicators for damage detection,and applying it to the damage detection of transmission tower structures.First of all,this article classifies the common damage detection methods at home and abroad,and introduces related research content and results of using time series model for damage detection.At the same time,it summarizes the relevant research results of domestic and foreign scholars in the damage detection of transmission tower.Subsequently,the basic theory of ARFIMA time series is introduced in detail,and the characteristics between the commonly used linear time series model ARMA and ARFIMA are compared.It is believed that the ARFIMA model can better describe the acceleration response sequence of the structure under natural excitation due to its memory characteristics.Then,the formula for calculating the cepstrum distance of the ARFIMA model is derived,and the ARFIMA model is combined with the cepstrum metric to propose a new damage detection index——ARFIMACM index.An eight-storey shearing building numerical simulation is performed to demonstrate the effectiveness of the proposed method.And for comparison,the damage detection method based on the cepstral distance of ARMA models is introduced.The results show that the proposed method can accurately determine the damage location of the structure and has certain potential in the quantitative analysis of the damage degree.Then,through an experiment of a three-storey frame structure model,the effectiveness and feasibility of the damage index based on the cepstral distance of the ARFIMA model is verified again.Finally,the damage detection method proposed in this paper is tested in an experiment of the transmission tower model,and good results are obtained.