FINITE-ELEMENT ANALYSIS OF LARGE-AMPLITUDE PANEL FLUTTER OF THIN LAMINATES

Large-amplitude panel flutter of thin rectangular composite laminates is studied using finite elements. The principle of virtual work is use d to develop the equations of motion of a fluttering rectangular panel . The large deflections are represented by von Karman strain-displacem ent relations and the aerodynamic load is represented by the use of th e quasisteady first-order piston theory. The equations of motion are s olved by implementing the lineared updated-mode with a nonlinear time function (LUM/NTF) approximation. Critical flutter values and limit-cy cle amplitudes for graphite-epoxy and boron-epoxy laminates at various boundary conditions, lamination orientations, and numbers of layers a re investigated.