Dynamic response of a flexural non-classically damped continuous beam under moving loadings

In this paper an extension of the complex mode superposition method is presented for the dynamic analysis of a uniform simply supported beam with two rotational viscous dampers attached at its ends subjected to a constant moving loading. The mass of the loading has been assumed small with respect to the beam mass and, therefore, has been neglected. A parametric analysis has been performed, which has shown that the effectiveness of the dampers in reducing the response amplitude strongly depends on the loading speed. A comparative study between the exact response functions, obtained by means of the complex modal analysis, and the approximate ones, provided by the classical modal analysis, has been performed showing significant differences. In those cases where the exact response is larger than the approximate one the reliability of approximate methods may be seriously affected.