Mechanical Analysis Of Continuous-span Curved Beams Considering Shear Deformation Effect

Three-dimensional urban traffic system is an important symbol of regional traffic developed level,which the curved girder bridge is widely applied in because of its strong ability to adapt.Compared with straight beam,the mechanical properties,structure,load,construction and other aspects of curved beam are more complex,and its structure not only bears moment and shear,but also has larger warping,twisting,and coupling effect of bending and torsion.Domestic and foreign scholars have done much systematic research on the curve beam,most of which is based on elementary beam theory,ignoring the influence of shear stress on internal force and deformation of curved beam.At present,the study on how shear stress affects curve beam structure is not in-depth,which needs further research.So this paper does the following research based on Timoshenko deep beam theory,through mix analysis method of structural mechanics and energy principle.(1)A deformation formula is derived considering the effect of shear deformation on single span statically indeterminate curve beam under five typical loads,and the influence rule of central angle,radius of curvature,section size’s change affecting the deformation of single span statically indeterminate curve beam is analyzed.It is put forward that deep beam theory should be adopted on the medium and small curved beam force analysis,otherwise it will underestimate the deformation calculation results.(2)A calculation formula of internal force and deformation is established considering the shear deformation influence on two span statically indeterminate curve beam under four kinds of common load,and shear effect on structure deformation of two span continuous beam by varying parameters such as span and curvature radius is analyzed.Studies show that central angle is larger with curvature radius under certain condition,while the influence of shear deformation effect of curve beam is less significant;When span is sure and the radius of curvature is larger,the shear effect on the deflection and rotation angle of two span curve beam will be smaller,however the influence on torsional angle is very significant,and the relative error rate variation is smaller.(3)A calculation formula of internal force and deformation is established considering the shear deformation influence on three span statically indeterminate curve beam under four kinds of common load,and the shear effect on structure deformation of three span continuous beam by varying ratio of side span to main span is analyzed.Studies show that the ratio of side span to main span is larger when span is sure,and the shear effect on the deflection and rotation angle of three span curve beam is smaller,however the influence on angle and twist angle is more significant.