Study On Torsion Behaviors Of Composite Beam With Corrugated Steel Web

Corrugated steel web composite box girder is a new type of composite structure that has been widely used in China's bridge structure in recent years.Broad development prospects.This paper relies on the National Natural Science Foundation project "Research on the Mechanism and Calculation Theory of Bending and Torsion of Prestressed Concrete Curved Composite Beams with Corrugated Steel Webs"(51778377),to test the mechanical performance of two corrugated steel web composite box beams under pure torsion Research and theoretical analysis,work done and main conclusions are as follows:(1)Carry out a static load model test of the torsional performance of a composite box girder with corrugated steel webs.The test results show that at the initial stage of loading,the torsional deformation of the test beam is small,and the relationship between the torsion rate and the torque increases linearly.After the torque reaches the cracking torque,the torsional stiffness of the test beam decreases,the torsion rate and torque increase non-linearly,and the concrete wing Spiral oblique cracks with an angle of 40 ° ? 45 ° with the beam axis began to appear on the plate.(2)A finite element model of the beam corrugated steel web composite box girder was established using ANSYS finite element analysis software,and the finite element analysis results were analyzed and compared with the experimental measured results.It was found that the experimental values were close to the finite element results,which verified that The correctness of the finite element model.Based on the finite element model,further parameter analysis of the corrugated steel web composite box girder is performed.The results show that the ultimate torsional capacity of the corrugated steel web composite box girder depends on the compressive strength of the concrete,the thickness of the corrugated steel web,and the initial The prestress and reinforcement strength ratios increase,but the influence of each parameter on the ultimate torsional capacity is different.(3)Equivalent load decomposition methods for arbitrary torque on single-box single-chamber section and single-box dual-chamber section are given,and torsion of corrugated steel web composite box girder with single-box single-chamber section and single-box dual-chamber section Effects and distortion effects are analyzed.It was found that under torsional and first distortion loads,the warping stresses of the concrete top and bottom plates of the composite box girder with corrugated steel webs are antisymmetrically distributed along the transverse position of the section;under the second distortion load,the section warping stresses The transverse position along the section was distributed in a positive symmetry.(4)Based on the original theories such as thin-walled box girder theory and space truss model theory,the superimposed method was used to obtain the torsional bearing capacity calculation formula of the corrugated steel web composite box girder.The analysis results are compared and found that the three results are relatively close.