Trigonometric Series Solutions For Torsion Behavior Of Composite Beam Bridge With Corrugated Steel Webs

The composite beam bridge with corrugated steel webs is an innovative composite structure,which avoids the problem that the weight of the structure occupies a large proportion of the total load.It is favored by the majority of engineers for the light weight,high prestressed efficiency,good construction performance.However,the corrugated steel web is thin,and the torsion resistance of the structure declined sharply.In the calculation the composite beam bridge with corrugated steel web,it's necessary to consider the torsional effect caused by partial load to ensure that it is more safe and reliable in the construction process.The main work of this article is as follows:1.The structural characteristics and torsional deformation characteristics of the composite beams with corrugated steel web are analyzed.The existing torsional analysis methods of the composite beams with corrugated steel web are divided into two types: The second theory of Umanski and the method of eccentricity magnifying coefficient.The former theory is clear in concept,accurate in result,but difficult to solve and cumbersome in computation.The latter theory is simple and easy to understand,but it lacks theoretical support and it's poor operability.2.The rigid torsional angle ? of composite beams is expressed by trigonometric series function based on the hypothesis of torsional analysis of box girder.And the calculation model of torsion angle of composite beams with corrugated steel web under concentrated torque is derived by using the principle of energy.The numerical simulation is carried out by establishing the spatial finite element model.The results and the experimental results of the related literature are compared with the analytic solution of the triangular series method.It shows that the accuracy of the maximum twist angle of the composite beam with corrugated steel webs by trigonometric series method is very high,and there is a certain difference in the deformation of the body of the calculated beam.The difference is more obvious in the calculation of cantilever composite beams.3.By solving the torsional angle function ?(x),the internal force,stress and shear stress are solved,and the results are compared with the numerical simulation results.The results show that:(1)The convergence rate of the double moment number is slower than the displacement function and the calculation precision in the internal force calculation;(2)The warpage stress calculated by the trigonometric series method has high accuracy;(3)The free torsion shear stress accounts for more than 90% of the torsional shear stress.The results gained would provide theory basis for design and calculation of the composite beam bridge with corrugated steel webs.