In this paper, the flexural vibration of Timoshenko beams, modeled as a series of intercon-nected distributed and lumped elements, is considered. The natural frequencies of a uniform beam with various boundary conditions are calculated based on the distributed lumped mod-eling technique (DLMT). The results obtained by this method are verified with the results of other techniques. The method is then employed for calculating the natural frequencies of a propeller shaft system using the Euler- Bernoulli and Timoshenko beam theories, and the re-sults are verified with FEM frequencies and mode shapes. It is shown that the presented method provides highly accurate results, while it can be simply and effectively applied to the complicated systems.

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