A Flii'gge-type theory is employed in studying the dynamic characteristics of simply supported shells of oval cross section. The components of displacement are expressed in a double Fourier series of the axial and circumferential coordinates and substituted into the equations of motion. This leads to four different typical, algebraic, eigenvalue problems from which the frequencies and shapes of four types of harmonic modes are determined. These modes are either symmetric or antisymmetric with respect to the principal axes of the cross section of the shell. A comparison of the dynamic characteristics of oval cylindrical shells obtained on the basis of the Donnell, Love, Sanders, and Flu'gge theories is presented. It is shown that the deviations in the results of these theories increase with increasing noncircularity.
NomenclatureA mn ,B mn ,C mn , D m,n> E m, n > F m"n = Fourier coefficients D = (\/\2)Eh 3 /(-v 2 ) E = Young' s modulus t -time u,v,w = axial, circumferential, and radial components of displacement of a point on the median surface of a shell, respectively U m ,V m , W m = displacement functions for axial wave number m ?>ij = Kronecker delta e = ovality parameter v = Poisson's ratio