Free vibrations of laminated beams using mixed theory

• Published in: Composite structures 2001-05, Vol.52 (2), p.149-160
• Main Authors: Kameswara Rao, M., Desai, Y.M., Chitnis, M.R.
• Format: Article
• Language: English
• Subjects: Composite materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Fatigue, brittleness, fracture, and cracks; Free vibrations; Laminated composite and sandwich beams; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Mixed theory; Physics
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/S0263-8223(00)00162-8

An analytical method for evaluating the natural frequencies of laminated composite and sandwich beams has been developed in this paper using higher-order mixed theory. The stiffness and mass matrices for the laminate are computed by evaluating the integrands explicitly. Each lamina of the laminate is assumed to be orthotropic and in a two-dimensional state of plane stress. Hamilton's principle has been employed to derive the equilibrium equations. Numerical experiments on laminated composite and sandwich beams of thin and thick sections are performed. The results obtained are compared with those of the first-order shear deformation theory and are validated by comparing them with the published results of analytical methods incorporating displacement-based higher order theories.