Study On Fatigue Characteristics Of Partially Prestressed Continuous Rigid Frame Bridge Based On The MSC Fatigue

By design,the bridge is under dead load and live load combinations according to the most unfavorable situation,uses the static strength to design,the dynamic load of the bridge under the action of repeated consider less fatigue cumulative damage,and the actual operation of the bridge under various load of the vehicle repeatedly,even in the case of has yet to reach its carrying capacity limit,bridge and concrete cracking,steel corrosion failure may occur,the overall carrying capacity of decline,and many other diseases.Therefore,the fatigue life of concrete bridges and use safety is paid attention to the height of the bridge management day by day.In order to ensure the safety of partial prestressed concrete bridge,it is necessary to conduct research on its fatigue life.This paper based on the project of Sanshui District,Foshan City,Golden Bridge(old bridge)the traffic data collection,has developed a typical fatigue model suitable for the section of the car.Finally,using the statistical principle and rain flow counting method for counting,extract the fatigue load spectrum under vehicle load.By MSC fatigue analysis software of partially prestressed continuous rigid frame bridge are checked,partially prestressed concrete continuous rigid frame bridge fine modeling process was to explore,a simplified simulation of the parts,the simulation effect is good.In this paper,based on the Miner linear cumulative damage theory,with Nominal Stress Method for fatigue life prediction method is used to analyze the structure,and finally the results of fatigue analysis show that: a great influence on bridge fatigue stress concentration phenomenon,should be in the structure to the stress concentration areas,strengthen the fatigue performance.The tension control stress of prestressed reinforcement for 1302 MPa,under the action of fatigue load,the fatigue life can be up to 7.9×10~6 above,the fatigue of the prestressed reinforcement is not control factors of bridge structure fatigue destruction.By adopting different prestressing degree of the bridge are analyzed,and the tension zone of the results found that the fatigue life of ordinary steel is the key factors that affect the bridge structure fatigue performance,in the process of using concrete is generally won't appear the fatigue phenomenon;And improve the tension zone of the prestressed degree can effectively improve the fatigue life of ordinary steel,improving the overall fatigue performance of bridge structure.So,set the appropriate prestressed degree is very important to improve the mechanical performance of bridges.