Composite Hanger Fatigue Property Of Concrete-filled Steel Tubular Tied Arch Bridge

Based on the highway bridge traffic load survey and statistical methods of inductive analysis, this paper builds fatigue load spectrum in form of numerical simulation using the Monte Carlo method and makes a comparative study on the fatigue analysis of hanger by adopting two different fatigue load spectrums. What’s more, stress amplitude rule and corresponding fatigue properties of hanger are calculated with the consideration of characteristics of composite hanger, which provides technical guidance for the design and maintenance of composite hanger. The main contents of the paper are as follows:1. Based on the inductive analysis of the basic theory of probability and statistics, the method of statistical analysis on the relevant measured data of vehicle load is made clear; besides, the inductive analysis on the relevant fatigue theory provides traditional methods of fatigue analysis as the basis method and application process of the present study on fatigue properties of hanger, which lays theoretical foundation for this study.2. Based on the basic theory of mathematical statistics, after making an analysis on borrowed data of vehicle load survey, the distribution types and statistical parameters of relevant factors of fatigue vehicle loads is made clear. By taking Monte Carlo method as the basic idea, fatigue load spectrum in the form of random traffic flow is generated under general running state, which provides load mode for fatigue design and analysis of highway steel bridges.3. The paper develops relevant algorithm programs of fatigue analysis. By using MATLAB software, the generating program of random traffic flow, the calculation program for stress history loaded on the influence line, statistical program for calculating the probability distribution of stress amplitude by rain-flow counting method are developed, which makes the fatigue analysis and calculation of composite hanger more convenient.4. Taking a real bridge as the support project, the paper makes analysis on the fatigue property of composite hanger. Two fatigue load spectrums are selected to load on the stress influence line of hanger, and then the probability distribution of stress amplitude of finished cable hanger and steel casing hanger is calculated; based on the linear fatigue cumulative damage rule and S-N curve, after calculating the fatigue cumulative damage degree of composite hanger the fatigue damage rule of composite hanger of concrete-filled steel tubular arch bridge is explored.