ABSTRACT
This study presents a dynamic evaluation of the Suaçui railway bridge considering the vehicle-structure interaction and subjected to heavy axle load trains (HAL). For this purpose, three-dimensional finite element models of the truss bridge, including the track, and train were developed. The dynamic response was obtained using ABAQUS® software which was programed with an iterative uncoupled method for vehicle-structure interaction considering track irregularities. The validation of the numerical models was performed through a comparison between numerical and experimental dynamic responses, in terms of displacements and acceleration of the bridge for the passage of DASH 9W Locomotives and GDE wagons. The experimental response obtained from a dynamic test under railway traffic revealed a good agreement with the numerical response.
The bridge Suaçui is located in the Vitória-Minas Railroad, close to Governador Valadares, a city in the State of Minas Gerais – Brazil. The bridge is a simply supported span with 41 m. The numerical responses were obtained based on a dynamic analysis considering vehicle-structure interaction, including the track irregularities, performed by AIVE program developed in Matlab and ABAQUS. More details about the program will be showed in the PhD thesis of the first author. Since geometrical and mechanical properties for locomotives and typical wagons used in the railways were not available, especially for 3D models, it was necessary to determine these parameters based on theoretical information. The optimization was carried out based on iterative procedure using genetic algorithm.
The experimental measurements of the track irregularities were not available, the power spectral density functions based on the results of measurements on US railway tracks was adopted. Visualization of the numerical model showing the displacement of the bridge and vehicle is shown in Figure 1. Numerical visualization of the displacement results of the uncoupled analysis of vehicle-bridge interaction. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig131_1.tif"/>
The experimental responses were evaluated in a dynamic test under railway traffic. The comparison between numerical and experimental results, in terms of displacements and accelerations in the mid-span of the bridge for the passage of iron ore train at 30 km/h, shows a good agreement. Finally, this investigation shows the importance to consider the vehicle-structure interaction analysis, due mainly to the dynamic contribution of the train to the system. Therefore, the inclusion of the inertia effects and heavy mass of the moving vehicles contributes decisively to the increase of the acceleration response and generate oscillations in the displacements. Particularly for this type of bridges that is completely composed for steel elements and the track is without ballast.
