Moving mass/load speed influence on the structural dynamic response of a bridge

Influência da velocidade da massa/carga móvel na resposta dinâmica da estrutura de uma ponte

Abstract

The increasing technological advance in the structural engineering field allows not only the design of better structures, but also the development of new methods. When it comes to bridges, more specifically, railway bridges, a special kind of attention is necessary since the dynamic nature of some external loads must be taken into account. In this study, the inertial effect caused on the structure by the moving vehicle is quantified and taken into consideration in the analyses, through the coupling of the vehicle mass matrix with the global mass matrix of the structure at each integration time step. The numerical dynamic analysis was performed by the LOADYN software, a computer program developed by the authors. The influence of the train speed on the structural dynamic response is analyzed. Comparisons between the structural responses with and without the vehicle inertial effect are made. The results show the importance of the inertial forces generated by the vehicle. Those forces must be taken into account, especially at higher speeds and mass ratios since they play an important role on the response magnitude and critical velocities.

Keywords:
structural dynamics; railway bridges; moving mass; numerical solution; LOADYN