Maupertuis-Lagrange mixed variational formula for laminated composite structures with a refined higher-order beam theory (Q1371546)

Maupertuis-Lagrange (M-L) mixed variational principle is obtained by using Legendre's transformation and Lagrange's multipliers. This principle is used to deduce the governing equations for laminated composite structures. A rational higher-order displacement-based one-dimensional theory for the analysis of laminated beams is presented. This theory is established using the M-L mixed variational formula to study the vibration behavior of a symmetric laminated beam subjected to normal and tangential traction fields. Numerical results for natural frequencies are obtained according to the classical, first- and higher-order beam theories.