Free vibration analysis of stiffened shells by the finite element technique

The paper presents the development of a new stiffened shell element and subsequent application of this element in determining natural frequencies and mode shapes of the different stiffened structures. In the present method each stiffener is treated as a discrete one. The stiffener is modelled in such a way that it can be placed anywhere within the shell element. The method has the advantage over most approximate analyses of being applicable to any shell and stiffener configuration. The analysis becomes considerably more flexible due to this idealisation. Various types of shallow and deep stiffened shell structures have been analysed and the results have been compared with the previously published results.