Fatigue Experimental Study Of Orthotropic Steel Bridge Panel Based On Large Span Suspension Bridge

Since the 1950 s,orthogonally steel bridge panels have been widely used in the field of bridges because of their advantages of light weight,good integrity,good wind resistance and good economic benefits.This structure is widely used in suspension bridges and other large span bridge.Although this structure has enriched the structure of the bridge and promoted the rapid development of the bridge structure,the orthotropic steel bridge deck is prone to fatigue damage,and many bridge accidents are caused by the fatigue problem.In this paper,Wanli Expressway is used as the engineering background,and the integral force analysis of the orthotropic steel bridge panel of the consort prince bridge is analyzed by ANSYS.Based on this,two full-scale segment models are designed and a full-scale section model test is carried out.The main research contents are as follows:(1)This paper introduces the development of orthotropic steel bridge deck,its component characteristics and its fatigue problems,and summarizes the related research at home and abroad.(2)This paper elaborates the basic concept and theory of fatigue analysis of steel structure,the theory of fatigue damage accumulation of various structures,and several commonly used steel bridge fatigue design methods.Describes the main methods of fatigue life evaluation of orthotropic steel bridge deck,points out the characteristics and application of these methods.Summarizes the national norms and the current domestic scholars on the fatigue load of the research results.(3)A 3-axis standard fatigue vehicle model suitable for the highway bridge in the southwest mountainous area of China was selected as the loading model,and a 32 m long multi-segment finite element whole plate shell model was established.In order to obtain the stress history of the critical fatigue parts,the bridge load and the vertical bridge are loaded with the selected vehicle load,and the stress frequency spectrum is calculated.According to the structural characteristics of fatigue details,the fatigue life is calculated by nominal stress method or hot stress method.(4)Based on the analysis results of the section analysis of the orthotropic steel bridge deck,two different full-scale model specimens were designed to carry out the full-scale model test.The test fixture was made and the corresponding loading scheme and measurement scheme were worked out.The finite element models of these two specimens are established respectively.The simulation results show that the results can be consistent with the experimental results.(5)Two test pieces were designed to carry out the fatigue test of the design life cycle.During the test,no cracks were detected by manual detection.And the stress values of the key points of the fatigue points measured under each static load test are basically linear with the applied load values.Test results show that the fatigue details are not caused by fatigue damage,the fatigue details are able to meet the design requirements.