By double Fourier transform and contour integration technique, a closed-form solution to the steady-state response of a uniform beam placed on Kerr foundation and subjected to a moving harmonic load was obtained. The beam was described as a Euler-Bernoulli beam, and the cut-on frequency and critical velocity of the foundation beam were determined based on the dispersive curve of Kerr foundation beam. The influences of the train speed, load frequency, coefficient of subgrade reaction and foundation shear coefficient on the deflection of foundation beam were investigated and the influence of foundation damping on the critical velocity and resonant frequency was also studied. Moreover, a two-dimensional beam-soil model was established to calculate the deflection of foundation beam under non-moving constant load and simple harmonic load. The numerical results were compared with the analytical solutions of Kerr foundation, Pasternak foundation, and the Winkler foundation. It is concluded that the Kerr foundation model can give best agreement with the FEM results, while the Winkler foundation model presents greatest discrepancy in static calculations. As for dynamic calculation, the time history responses base on different types of foundation beam models are only close to the numerical results at the places near the applied load.
Key words
Kerr foundation model /
deflection of foundation beam /
dispersive curve /
foundation damping /
moving oscillating load
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References
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