【摘要】 为了解双工字钢组合梁桥偏载扭转效应对钢主梁应力的影响，并能准确计算其扭转应力，以淮河特大桥引桥为背景，进行有限元及理论计算。采用ANSYS软件建立引桥有限元模型，结合有限元计算结果，理论分析钢主梁跨中及支点处的扭转翘曲正应力和弯曲正应力；研究桥梁跨径、钢主梁高度、桥面板厚度、横梁间距、钢主梁间距等参数对钢主梁扭转效应的影响；提出采用修正系数计算偏载系数及考虑弯扭耦合效应的钢主梁扭转应力简化计算方法，并与有限元结果进行对比。结果表明：偏载作用下钢主梁的纵向正应力大于均布荷载作用，最大超过20 MPa,偏载作用下的扭转效应不能忽略；钢主梁间距对钢主梁翘曲效应影响较大，其余参数影响较小；提出的钢主梁扭转应力简化计算方法与有限元法计算结果偏差较小。更多还原

【Abstract】 In this paper, the approach viaduct of Huaihe River Bridge is used as a case to investigate the influence of torsion effect on stresses in steel girders of the composite girder bridge consisting of twin-I steel girders and concrete slabs and figure out the torsion effect computation method. The theoretical computation was supplemented with finite element analysis(using ANSYS)to analyze the torsional warping normal stress and bending normal stress in steel girders at midspan and supports. The effects of parameters, including the span length, steel girder depth, deck slab thickness, spacing of floor beams and spacing of the twin I steel girders, on the torsion effect of the steel girders were examined.It is shown that the longitudinal normal stress in the steel girder under eccentric loading is greater than that under uniform loading, with a maximum difference exceeding 20 MPa, indicating that the torsion effect under eccentric loading should not be omitted. The influence of the spacing of the twin I steel girders is more significant than the other parameters mentioned. There is a minor deviation between the torsional stress of the steel girder obtained by the proposed simplified computation method and that acquired by finite element calculation.更多还原