Free vibration of a Timoshenko beam partially loaded with distributed mass

Exact frequencies and mode shapes have been calculated for a Timoshenko beam, on different boundary supports and partially loaded with a distributed mass span. They agree with experimental data. For the higher modes, frequencies obtained through the Euler-Bernoulli theory are not as accurate as the Timoshenko ones. Results show the effects of the added mass length, position and density on natural frequencies. The variation is cyclical with range depending on the added mass inertia. For certain loading, the range of variation is small, showing frequency to be insensitive to added mass location. (C) 1997 Academic Press Limited.