A spectral element for laminated composite beams: theory and application to pyroshock analysis

In this article a spectral element for anisotropic, laminated composite beams is developed. Firstly, the axial-bending coupled equations of motion are derived under the assumptions of the First order Shear Deformation Theory, then the spectral element matrix is formulated. The proposed spectral element is validated by comparing, with corresponding results from the scientific literature, natural frequencies of a number of both orthotropic and anisotropic laminated composite beams and the dynamic response of an anisotropic cantilever beam to high frequency transients. Finally, the application of the proposed element to the evaluation of the dynamic response to a simulated pyroshock of an idealized satellite structure made of sandwich beams is shown.