A dynamic theory for laminated composites consisting of anisotropic layers

Yalçın, Ömer Fatih
In this thesis, first a higher order dynamic theory for anisotropic thermoelastic plates is developed. Then, based on this plate theory, two dynamic models, discrete and continuum models (DM and CM), are proposed for layered composites consisting of anisotropic thermoelastic layers. Of the two models, CM is more important, which is established in the study of periodic layered composites using smoothing operations. CM has the properties: it contains inherently the interface and Floquet conditions and facilitates the analysis of the composite, in particular, when the number of laminae in the composite is large; it contains all kinds of deformation modes of the layered composite; its validity range for frequencies and wave numbers may be enlarged by increasing, respectively, the orders of the theory and interface conditions. CM is assessed by comparing its prediction with the exact for the spectra of harmonic waves propagating in various directions of a two-phase periodic layered composite, as well as, for transient dynamic response of a composite slab induced by waves propagating perpendicular to layering. A good comparison is observed in the results and it is found that the model predicts very well the periodic structure of spectra with passing and stopping bands for harmonic waves propagating perpendicular to layering. In view of the results, the physical significance of Floquet wave number is also discussed in the study.


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The path integral representation for the propagator of a spinning particle in an external electromagnetic field is derived using the functional derivative formalism with the help of a Weyl symbol representation. The proposed method essentially simplifies the proof of the path integral representation starting from the equation for the Green function and automatically leads to a precise and unambiguous form of the boundary conditions for the Grassmann variables and puts a strong restriction on the choice of t...
Citation Formats
Ö. F. Yalçın, “A dynamic theory for laminated composites consisting of anisotropic layers,” Ph.D. - Doctoral Program, Middle East Technical University, 2006.