Comparative Study On Cutout Geometry Of Orthotropic Steel Bridge Decks Applied On Railway And Highway Bridges

In order to study the applicability of typical cutout geometries on orthotropic steel bridge deck(OSBD)in railway and highway bridges,four different types of cutout geometries are selected respectively to establish OSBD panel models based on a cable-stayed bridge of heavy transportation railway.Through the finite element simulation,the applicability of different types of cutout geometries in railway and highway bridges is compared and analyzed.Main contents and conclusions are listed as follows:(1)The OSBD panel model of railway and highway is established by using ANSYS software.This paper presents the results of the stress curve,stress contours and deformation scenario of the three details adjacent to rib-to-floorbeam connections and cutout details.Furthermore,the fatigue life evaluation is also carried out.It is observed that the stress range of cutout details is the largest among the four connection details under railway or highway wheel loads;Under the passage of wheel loads,the stress of four connection details first increases and then decreases.Due to the load distribution function of sleeper and ballast,the individual axle can’t be identified in the stress curve at four connection details.Only one stress range cycle in the stress curve is observed,and the stress local effect of steel deck under wheel loads is greatly reduced.Under highway wheel loads,the individual axle can be identified in the stress curve at rib-to-floorbeam connection details rather the cutout details.The result also shows that the cutout geometry recommended for railway OSBD in Eurocode 3 performs best among the four types of cutout geometries in railway bridges,followed by the cutout geometry recommended for highway OSBD in Eurocode 3 and the cutout geometry recommended by AASHTO LRFD,while the cutout geometry used in Xihoumen bridge do not sh ow apparent advantage.As the other three types of cutout geometries have on obvious advantages,it is suggested that the cutout geometry recommended for highway OSBD in Eurocode 3 performs best in highway bridges.(2)Based on the results of finite elemen t analysis,the stress range of four connection details with each cutout geometry under the most unfavorable load condition are given,and the vertical and longitudinal deformation diagrams under wheel loads at five positions are listed.With the change of the position of wheel load,the rib and deck experience repeated deflection,and its adjacent diaphragms subject out-of-plane deformation.When the wheel loads act on the five positions of the span,the deformation on the diaphragm and cutout can be summarized as: under railway loads,the longitudinal deformation of four types of cutout geometries changes f rom large to small,while the vertical deformation degree is adverse.The longitudinal deformation of four types of cutout geometries is small when high way wheel loads acts near the diaphragm,and the deformation increases as the loads are close to the center of the span;as the wheel load moves away from the diaphragm,the vertical deformation decreases gradually.(3)The influence of heavy freight trans portation on fatigue performance is analyzed and compared at four connection details considering the four cutout geometries.The results show that under the most critical load condition in the transverse direction,the heavy freight transportation has litt le effects on the most critical load position in the longitudinal direction and the stress range of the cutout details,but it has great influence on the three details of rib-to-floorbeam connections.The stress range with heavy freight transportation incr eases by 53%,21% and 35% respectively at three details of rib-to-floorbeam connections.The results and conclusions of this paper can provide significant reference for the application of OSBD in railway and highway bridges.