基于高阶剪切理论单箱多室箱梁弯曲及自振研究OA

This paper stuelies the analytical solutions of deflection and vibration fundamental natural frequency of a single-box multi-cell box girder,and analyzes the influence of related factors.Based on the high order shear deformation theory,the axial displacement function of the single-box multi-cell box girder in exponential form was constructed,and the differential equation for bending deformation of the box girder was obtained.The general equation for deflection curve of the single-box multi-cell box girder was derived by using the singular function of external load set.Based on Galerkin principle,the fundamental frequency of the single-box multi-cell box girder was obtained by taking the deflection curve equation of the beam under uniform load as weight function.The calculation accuracy of the high order shear deformation theory to solve the deflection and vibration natural frequency of the single-box multi-cell box girder was verified by the relevant examples.The results show that the application of high order shear deformation theory to solve the deflection and vibration fundamental natural frequency of single-box multi-cell box girder is found in good agreement with the related literature data,which reflects the high calculation accuracy and reduces the difficulty of solving the differential equation and the transcendental equation.The shear deformation has a great influence on the natural frequency of the single-box multi-cell box girder,and the influence becomes greater with the strengthening of the supports at both ends of the box girder.The research provides a simple,rapid and effective analytical calculation method for solving the bending deformation and natural vibration fundamental natural frequency of single box multi-cell box girders.