Flexural Wave Propagation in Periodic Stiffened Plate Structures Using Finite Element Method

Phononic crystals exhibit unique dynamic characteristics that make them act as tunable mechanical filters for elastic or acoustic wave propagation. The introducing of the idea of PCs in engineering structures provides a new technique for the control of vibration and noise. In this paper, basing on the Mindlin plate theory, the Timoshenko beam theory and the Bloch theorem, an efficient finite element model is developed to describe the propagation of elastic waves in periodic stiffened plate structures with arbitrarily oriented stiffeners undergoing flexural vibration. The band structure of a stiffened plate structure and mode shapes of the unit cell are calculated using the proposed model and compared with the predictions of the commercial finite element MSC.Nastran. The obtained results demonstrate the effectiveness of the proposed model.