任意非对称截面薄壁箱梁畸变效应分析OA

In order to analyze the distortion effect of thin-walled box girders with asymmetric cross section,a general expression for the distortional warping rate was established based on the compatibility relationship be-tween the corner displacement and the in-plane displacement of each plate.The concept of anti-distortion stiff-ness for asymmetric box cross sections was introduced,and the energy variation principle was applied to estab-lish the governed differential equation for distortion of box girders with arbitrary asymmetric cross section.Based on the beam-segment finite element formulation,a program for analyzing the distortion effect of box girders with arbitrary asymmetric cross section was developed to achieve integrated calculation of the distor-tional warping geometric property,the distortional generalized internal force and displacement,and the distor-tional warping stress of the box girders with arbitrary asymmetric single-cell cross section.The research results show that the calculation results by the analytical method are generally in a good agreement with those by the Ansys shell element.The maximum value of the distortional warping normal stress of the asymmetric cross section box girder with inclined top plate is located at the intersection of the lower web plate and the bottom plate,and significant distortional warping shear stress occurs inside the bottom plate.For concrete box gird-ers,distortion effect may cause in-plane diagonal crack in the bottom plate,and the unfavorable effect should be fully considered in design process.