Analysis of Dynamic Impact Factors of Bridge Due to Moving Vehicles Using Finite Element Method

This article presents analysis of dynamic impact factors for displacement, bending moment, and shear force of bridge under moving vehicles by finite element method. Vehicle is a dumper truck with three axles. Each axle of vehicle is idealized as two mass dynamic systems, in which a mass is supported by a spring and a dashpot. The structural bridges are simulated as bending girder elements. The finite element method is applied to establish the overall model of vehicle–bridge interaction. Galerkin method and Green theory are used to discrete the motion equation of vehicle–bridge system in space domain. Solutions of the motion equations are solved by Runge–Kutta–Mersion method (RKM) in time domain. The numerical results are in good agreement with full-scale dynamic testing under controlled traffic condition of the super T concrete girder at NguyenTriPhuong Bridge in Danang city, Vietnam. Numerical results figure out that there are significant differences between dynamic factors for displacement, bending moment, and shear force. Therefore, the common use of only one dynamic impact factor for displacements, bending moment, and shear forces of bridge structure in each limited state should add more consideration. Furthermore, current results are references for bridge engineers to have more information for safety design requirements and suitability in bridge operation.