Dynamic Pressure Simulation Analysis Of Steel Bridge Deck Pavement With Cracks

As a key technology of long-span bridge construction,steel bridge deck pavement has become a research focus in recent years.Under the influence of different loads,different temperatures,and fatigue damage,the deformation and stress conditions of the steel bridge deck directly paved with asphalt pavement is far more complex than that of highway pavement.From the examples of many long-span bridges at home and abroad,the performance of epoxy asphalt pavements,which are superior to modified asphalt and ordinary asphalt concrete pavements,is also easy to produce many diseases,especially the cracks.Most of the maintenance of steel bridge deck pavement is concentrated in the rainy season.In this paper,the steel bridge deck pavement with cracks under seeper is analyzed and studied,and the water damage problem of the steel bridge deck pavement with cracks is studied.Firstly,the formation mechanism of hydrodynamic pressure and its influence on steel deck pavement are investigated in detail.Secondly,FLUENT software is used to establish a fluid-structure coupled finite element model and carry out simulation analysis based on the method of computational fluid dynamics.The distribution of the fluid distribution and the pressure distribution inside the crack during the movement are analyzed.And by controlling the variables such as vehicle speed,water film thickness,crack width,crack depth and the distance from the center of the tire to the center of the crack,the distribution of mixed fluid and the pressure distribution in the cracks of the pavement under various working conditions are studied.Thus,the most unfavorable factor affecting hydrodynamic pressure in pavement cracks is obtained.The analysis results show that:with the increase of speed,the thickness of water film,the depth of cracks and the crack width,the dynamic water pressure and the maximum dynamic water pressure in the cracks are all increased,and the degree is relatively different..The change of distance between tire center and crack center is discussed,When the distance is 30cm,the dynamic water pressure at the crack changes greatly.Furthermore,considering the hydrodynamic pressure,the J integral is used to quantitatively characterize the stress and strain fields at the crack tip.The variation of the dynamic water pressure and the crack depth is used to analyze the change law of the J integral at the crack tip,which can be used for reference for the calculation of the fracture parameters in the steel bridge deck pavement with the action of dynamic water pressure.The analysis results show that when the crack depth is constant,J integral increases with the increase of hydrodynamic pressure,and 0.2Mpa is a key value of hydrodynamic pressure.In the case of constant pressure,2cm is a key value of crack depth.