Two-span bridge under moving load – numerical and experimental approach

Abstract

From the point of view of bridge structures, the moving load is one of the most important components of the load. The analysis of the influence of moving load on bridges is carried out numerically or experimentally and can be traced in the literature since the year 1849. The first impulse was the collapse of the Chester Rail Bridge in England in the year 1847. The present paper analyses the effect of the moving load on a two-span bridge, both numerical and experimental way. The planar model of the vehicle and the bridge is adopted. The bridge is modeled as Bernoulli-Euler beam. The heavy vehicle is modeled as a discrete computational model with 8 degrees of freedom. Two approaches are used in numerical modeling. For the first time, the task is solved by the finite element method in the environment of the program system ADINA. The Newmark's method is used for the solution of equations of motion. The classic approach is used for the second time. A discrete computational model of a bridge with two degrees of freedom is used. Equations of motion are solved numerically in the environment of program system MATLAB by the Runge-Kutta 4th order method. The influence of vehicle speed on vertical deflections in the middle of individual bridge fields is analyzed in the speed range from 0 to 130 km/h with a step of 5 km/h. The detailed comparison of both numerical approaches is made at a vehicle speed of 70 km/h. The deflections of the bridge and the deflection of the vehicle are compared with each other. The correctness of the assumptions used in the numerical solutions was verified by measurement on a model beam in the laboratory. The results of the experimental tests were compared with the results of the numerical solution.

Numerical Investigation on the Transverse Vibration of Prestressed Large-Span Beams with Unbonded Internal Straight Tendon

“…Thus, the element size 50 mm was carefully chosen for the sake of optimality and efficiency. For the moving load problem, a numerical example from Yang and Yau [ 25 ] and the test results of a moving mass on a two-span continuous beam from [ 38 ] were selected to verify the FEM simulation. The dynamic responses of the midspan deflections have been plotted in Figure 9 , which are within the rational error margins with those of the reference.…”