An equivalent layer-wise approach for the free vibration analysis of thick and thin laminated and sandwich shells

摘要: The main purpose of the paper is to present an innovative higher-order structural theory accurately evaluate natural frequencies laminated composite shells. A new kinematic model developed starting from theoretical framework given by a unified formulation. expansion taken as free parameter, and three-dimensional displacement field described using alternatively Legendre or Lagrange polynomials, following key points most typical Layer-wise (LW) approaches. structure considered unique body all geometric mechanical properties are evaluated on shell middle surface, idea well-known Equivalent Single Layer (ESL) models. For this purpose, name Layer-Wise (ELW) introduced define approach. governing equations solved numerically means Generalized Differential Quadrature (GDQ) method solutions compared with results available in literature obtained through commercial finite element program. Due generality current method, several boundary conditions various configurations considered. Finally, it should be underlined that different doubly-curved surfaces may mathematical differential geometry.