Wave propagation in periodic stiffened shells: spectral finite element modeling and experiments

2001 ◽  
Author(s):  
G. Solaroli ◽  
Zheng Gu ◽  
Massimo Ruzzene ◽  
Amr M. Baz
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Finite Element Modeling ◽  
Element Modeling ◽  
Stiffened Shells ◽  
Modeling And Experiments ◽  
Spectral Finite Element

Wave Propagation in Periodic Stiffened Shells: Spectral Finite Element Modeling and Experiments

2003 ◽  
Vol 9 (9) ◽  
pp. 1057-1081 ◽  
Author(s):  
G. Solaroli ◽  
Z. Gu ◽  
A. Baz ◽  
M. Ruzzene
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Periodic Structures ◽  
Dynamic Stiffness ◽  
Geometrical Parameters ◽  
Pass Band ◽  
Matrix Formulation ◽  
Stiffened Shell ◽  
Stiffened Shells ◽  
Spectral Finite Element

The capability of periodic structures to act as filters for propagating waves is used to control the propagation of waves in thin shells. The shells are stiffened by periodically placed rings in order to generate periodic discontinuities in the stiffness and inertial spatial distribution along the longitudinal axes of these shells. Such discontinuities result in attenuation of the wave propagation over certain frequency bands called stop bands. A distributed-parameter approach is used to derive a spectral finite element model of the periodically stiffened shell. The model accurately describes the dynamic behavior of the shell using a small number of elements. The stiffening rings, modeled using the curved beam theory, are considered as lumped elements whose mass and stiffness matrices are combined with those of the shell. The resulting dynamic stiffness matrix of the ring-stiffened shell element is used to predict the wave propagation dynamics in the structure. In particular, the shell propagation constants are determined by solving a polynomial eigenvalue problem, as a numerically robust alternative to the traditional transfer matrix formulation. The study of the propagation constants shows that the discontinuity introduced by the stiffeners generates the typical stop/pass band pattern of periodic structures. The location and width of the stop bands depend on the spacing and geometrical parameters of the rings. The existence of the stop bands, as predicted from the analysis of the propagation constants, is verified experimentally. Excellent agreement between theoretical predictions and experimental results is achieved. The presented theoretical and experimental techniques provide viable means for designing periodically stiffened shells with desired attenuation and filtering characteristics.

Sign in / Sign up

Export Citation Format

Share Document