Dynamic response analysis of girder-orbit systems considering the constraining effect of orbit extension under moving load

In order to examine the dynamic response of a girder-orbit-moving load coupling system considering the constraint effect of the orbit extension, an analytical calculation method for the dynamic response of the girder-orbit system with arbitrary boundary conditions under a moving load is proposed based on the finite Fourier transform. Using the analytical calculation method, the dynamic response of the girder-orbit system with orbit extension at different moving load speeds is calculated, and the calculated results are compared with ANSYS finite element numerical calculation to examine the effect of moving load speed, orbit and girder flexural stiffness, interlayer spring stiffness, and orbit extension length on the dynamic response of the system. Results show that the analytical calculation results are in good agreement with the ANSYS calculation results, verifying the correctness of the analytical calculation method. The amplitude-moving load velocity relationship curve of the girder-orbit system dynamic response is a waveform curve. The interlayer spring stiffness, orbit flexural stiffness, and orbit extension length have significant effects on the dynamic response of the orbital layer, but the effect on the dynamic response of the girder layer is not significant.