Accession Number : ADA310573

Title :   Mixed Finite Element Models for Free Vibrations of Thin-Walled Beams.

Descriptive Note : Technical paper,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s) : Noor, Ahmed K. ; Peters, Jeanne M. ; Min, Byung-Jin

PDF Url : ADA310573

Report Date : FEB 1989

Pagination or Media Count : 30

Abstract : Simple, mixed finite element models are developed for the free-vibration analysis of curved, thin-walled beams with arbitrary open cross section. The analytical formulation is based on a linear, Vlasov-type, thin-walled beam theory with the effects of flexural-torsional coupling, transverse shear deformation, and rotary inertia included. The fundamental unknowns consist of seven internal forces and seven generalized displacements of the beam. The element characteristic arrays are obtained by using a modified form of the Hellinger-Reissner mixed variational principle. Only C continuity is required for the generalized displacements. The internal forces and the Lagrange multiplier are allowed to be discontinuous at interelement boundaries. Numerical results are presented to demonstrate the high accuracy and effectiveness of the elements developed. The standard of comparison is taken to be the solutions obtained by using two-dimensional plate/shell models for the beams.

Descriptors :   *VIBRATION, *FINITE ELEMENT ANALYSIS, *CANTILEVER BEAMS, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, STRESS ANALYSIS, MATRICES(MATHEMATICS), STRUCTURAL ANALYSIS, DEFORMATION, DISPLACEMENT, ACCURACY, SHEAR STRESSES, PARTIAL DIFFERENTIAL EQUATIONS, PERTURBATIONS, FLEXURAL PROPERTIES, TORSION, AXIAL LOADS, LAGRANGIAN FUNCTIONS, MOMENT OF INERTIA.

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE