Fatigue Analysis Of Reinforced Concrete Bridge Under The Vehicle Load

Structures many of which are in the field of aerospace, road and rail undervibration loading environment.these structures often lead to fatigue failure becauseof the role of cyclic loading. Actual operations in the bridge due to repeated heavyvehicles, uninterrupted disturbance (alternating) loads, easily lead to the occurrenceof fatigue damage and destruction. With the rapid development of China’s nationaleconomy, the number of vehicles and load operations are rapidly increasing, a largenumber of existing bridges to the prevalence of low design load, lack of carryingcapacity and other issues. Therefore, research of the bridge fatigue problem under thevehicle load is imminent.This paper calculated that the bridge’s bearing capacity under static load andbridge service life under the action of cycle vehicle loads, and then analysis of theimpaction of overloaded vehicles on the bridge. Using the explicit dynamic finiteelement software to calculate and simulate the ultimate bearing capacity of the bridgeunder static load.. And vehicle load spectrum through on-site traffic flow survey, theuse of transient analysis, rainflow counting method, linear cumulative damage theoryto calculate the bridge service life, and finally discuss the case of overloaded vehicleson the bridge life. In addition, we also studied the relationship between speed and thevehicle dynamic magnification factor.The main innovation of the article as follows:1This article does not consider the bridge uneven pavement of the degree of thevehicle deck load as an instantaneous half-sine shock load. Then consider the bridgefundamental frequency to analysis, trying to get new ideas to calculate the vehicleload amplification factor.2In this paper, using PLASTIC-KINEMATIC as the steel bars material modelinside the box girder and H-J-C as a concrete material model to numerical simulatethe damage of box girder under the ultimate load, and getting a good result.3In this paper, using the traffic survey to get the vehicle load spectrum. Usingthe transient analysis to calculate vehicles with different number of axles through thebridge’s dynamic response, and the steel bars inside the box girder cyclic axial stresscurve was obtained. Rain flow counting method reinforced loop on the front from theaxial stress curve grading to the linear cumulative damage theory to calculate thebridge service life, and discussed the overload on the bridge life...