Study On Bucking Performance Of Variable Cross-section Corrugated Steel Webs With Horizontal Diaphragms

The box girder with variable cross-section corrugated steel webs with horizontal diaphragms is a new type of box girder structure,which is composed of concrete roof,corrugated steel webs,concrete floor and concrete horizontal diaphragms.In the design of this kind of box girder,the web height is relatively high,so the shear buckling problem of corrugated steel web is particularly prominent.In order to improve the shear buckling capacity of corrugated steel web,in a certain height range from the bottom plate,the horizontal diaphragm is designed to support the web out of plane,so as to improve the buckling strength of corrugated steel web.In order to analyze the buckling behavior of corrugated steel webs with the horizontal diaphragms,this paper takes the Yellow River Bridge as the engineering background,and uses the methods of theoretical calculation and numerical simulation to study the buckling behavior and buckling control factors of corrugated steel webs in the single plate model and the whole bridge model:(1)The elastic buckling theory of plate and shell is analyzed,and the calculation methods of buckling strength of corrugated steel webs in previous literature are summarized,including elastic local buckling,elastic global buckling and elastic interactive buckling.The nonlinear buckling performance of corrugated steel webs in the design process is analyzed and studied.Taking the size of corrugated steel webs in the actual engineering background as an example,the theoretical calculation and analysis are carried out.(2)The ANSYS finite element model of corrugated steel webs is established and its correctness is verified;Taking the 1600 type corrugated steel webs in engineering background as an example,the buckling parameters of corrugated steel webs are numerically analyzed.The effects of height span ratio and thickness on the buckling mode and buckling strength of corrugated steel webs with equal section and variable cross-section are compared,and the influence of restraint height on the buckling performance of corrugated steel webs with variable cross-section under the action of horizontal diaphragm is analyzed;According to the results of parametric analysis,the relationship between the buckling strength of corrugated steel webs with variable cross-section and that of corrugated steel webs with equal cross-section is fitted.(3)Taking the composite box girder bridge with corrugated steel webs with horizontal diaphragms as an example,the finite element model of ABAQUS is established to analyze the ultimate bearing capacity and failure mode of corrugated steel webs with and without horizontal diaphragms;The design shear buckling strength is checked,and the influence of different corrugated steel web thickness on the bearing capacity and failure mode of the whole bridge is analyzed.