LARGE-AMPLITUDE FINITE-ELEMENT FLEXURAL VIBRATION OF PLATES STIFFENEDPLATES

Large-amplitude free flexural vibration of stiffened and unstiffened p lates has been studied by using the finite element method. An isoparam etric quadratic plate-bending element has been used both for the plate and the stiffener. The dynamic version of von Karman's field equation s has been adopted and the formulation has been done in the total Lagr angian coordinate system. The in-plane deformation and inertia have be en taken into account. The resulting nonlinear equations have been sol ved by the direct iteration technique using a linear mode shape as the starting vector. The stiffener has been elegantly modeled so that it can be placed anywhere within the plate element and it need not follow the nodal lines. This has increased the flexibility of the mesh gener ation considerably. The arbitrary orientation and eccentricity of the stiffener have been incorporated in the formulation. The shear deforma tion has been incorporated according to Mindlin's hypothesis. Stiffene d and unstiffened plates that have various boundary conditions have be en analyzed and the results have been compared with those available in the literature.