Bending And Torsion Analysis Of Thin-walled Curved Girders Using Semi-discrete Semi-precise Integration Method And Considering Shear Lag

Due to the beautiful appearance and the saving of building space,the curved girder structure plays an important role in the modern bridge engineering and highway engineering fields.However,because of the characteristics of bending and torsion coupling of curved girders,it has its own speciality and complexity compared to straight girders.At the same time,shear lag will occur in the actual structure.The analysis of the bending and torsion coupling of the curved beam while considering the shear lag is very important and has practical engineering significance.This paper studies the bending and twisting phenomenon of thin-walled curved beams.Abandon the assumption of longitudinal warp displacement by using the Umanski theory and elementary girder theory.Linear differential function is used to simulate the expression of longitudinal warp displacement function.According to the basic assumptions,the displacement field of the thin-walled curve beam is established,and the linear interpolation function is introduced to obtain the strain field of the structure.Furthermore,the total energy expression of the bending-torsion coupling of the thin-walled curved beam considering the shear lag is deduced.According to the energy variation method,the Lagrange equation of the structural system is obtained.Using the Legendre Transform to lead in Dual Variables,and then derive the Hamiltonian canonical equation.For solving the generalized and generalized displacements of the thin-walled curved box girder considering the shear lag,a precise integration algorithm of two-point boundary value problem is used to solve the problem.Finally calculate the examples in the literature,and compare the results with the results calculated by different methods in other literature.Therefore,it is proved that the method is reasonable and feasible.