| Cable-stayed bridges are relatively mature bridges in the current bridge structure.Due to their long span and soft structure,they are susceptible to fatigue and damage caused by traffic loads and wind loads.The cable stays of key components of cable-stayed bridges are particularly affected by them.Therefore,the study of its fatigue reliability has become a hot issue.At present,the analytical method for analyzing the dynamic response of bridges under traditional analysis of wind loads and traffic loads is costly,and there are relatively few researches on the fatigue reliability of cables considering the dual random effects of traffic loads and wind loads,considering the influence of corrosion on the operating environment.The related research on the fatigue reliability of cables for cable-stayed bridges has rarely been reported.The regularity and mechanism of the influence of corrosion factors on the fatigue reliability of cable stays under random traffic and wind loads are not yet clear.Based on this,this paper researches the applicability of the wind-vehille superposition analysis method.The reliability evaluation method of cable for cable-stayed bridges under random traffic and wind loads considering the effect of corrosion and the influence of load randomness.This paper relies on the actual cable-stayed bridge case,selects a reasonable modeling method,and establishes finite element analysis model by ANSYS.Based on the bridge traffic investigation data,six typical models were summarized,and the effects of vehicle type,vehicle speed,and deck level on the cable tension were studied.Based on the dynamic analysis and pseudo-static analysis of the vehicle-bridge coupling system,the stress amplification coefficients of the cable under different vehicle models and vehicle speeds are calculated,and the distribution rules are studied.Combining with the stress amplification factor of cable,through the influence of line loading method to solve the time-delay of the cable load of the traffic load,combined with the time history of the pull-wire stress of the wind load,a simplified calculation method for the analysis of the superposition of the traffic and wind loads are proposed,and its applicability is studied for the follow-up researches.According to the bridge traffic survey data and wind environment characteristics,the random traffic load and random wind load of the bridge case are simulated.Based on the analysis method of the windmill superposition effect,the time history of the pull-wire stress of the random vehicle load and the random wind load is calculated,and the linearity based on the Miner criterion is adopted.The fatigue reliability analysis method was used to study the fatigue reliability of cable,and the influence of the randomness of the load was studied.Based on the fatigue strength test data of artificial accelerated corrosion cable highstrength steel wire obtained from the existing research,the cable S-N curves under the influence of different corrosion grade pull-down cable S-N curves and time-varying corrosion were obtained.Based on this,the consideration based on the linear Miner cumulative damage theory was derived.The corrosion reliability assessment method and analysis process influenced by corrosion factors,fatigue reliability analysis of cables considering corrosion effects were summarized,relevant laws were summarized,and reference was provided for the maintenance management of cable stayed bridges. |
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