Influence of calculation methods of frame stiffness on distortion effect analysis of box girders
The influence of the frame stiffness calculated by the displacement method and force method on the analysis results of distortion effect of box girders was studied.Firstly,the analytical formulas of moment of in-ertial against distortion of box girders were derived by the displacement method and force method,respective-ly,and then distortion differential equations were established.Meanwhile,initial parametric solutions of the equations were provided when box girders were subjected simultaneously to eccentric uniform and concentrated loads.The distortion effects of a cantilever box girder model and a simply supported box girder example were studied by the two theoretical methods and finite element software.The results show that the distortion warping normal stresses,distortion transverse normal stresses and distortion angles of the box girders with rectangular section calculated by the two analytical methods are consistent,and they are in good agreement with the meas-ured values and finite element results.In addition,the distortion moments and distortion bi-moments of the box girders with trapezoidal section calculated by the two analytical methods are basically consistent,and they agree well with the finite element results.However,there is obvious difference in the distortion angles and transverse bending moments per unit width of the box girders with trapezoidal section calculated by the two methods,and the transverse bending moment per unit width calculated by the force method is closer to the fi-nite element result.With the increase of the inclination of webs,the distortional frame stiffnesses calculated by the two analytical methods and their difference increase,but the distortional warping stiffnesses decrease firstly and then increase.
万方数据
维普
