Affiliations: Aerospace Research Engineer, Aerospace Structures
Group, NASA Center for Aerospace Research, North Carolina A&T State
University, 1601 E. Market St., Greensboro, NC 27410, USA. Tel: +1 336 334
7255; Fax: +1 336 334 7417; E-mail: ghoshal@ncat.edu | Department of Aerospace Engineering, Indian Institute
of Technology, Kharagpur, Kharagpur-721302, India. Email:
parthan@aero.iitkgp.ernet.in | Graduate Research Assistant, McNair Research Fellow,
Structural Dynamics and Control Laboratory, North Carolina A&T State
University, 1601 E. Market St., Greensboro, NC 27410, USA. Tel.: +1 336 334
7260 x606; Fax: +1 336 334 7417; Email: dhughes@ncat.edu | Department of Mechanical Engineering, North Carolina
A&T State University, 1601 E. Market St., Greensboro, NC 27410, USA. Tel.:
+1 336 334 7260 x313; Fax: +1 336 334 7417; E-mail: schulz@ncat.edu
Note: [] Corresponding author
Abstract: In the present paper, concept of a periodic structure is used to
study the characteristics of the natural frequencies of a complete unstiffened
cylindrical shell. A segment of the shell between two consecutive nodal points
is chosen to be a periodic structural element. The present effort is to modify
Mead and Bardell's approach to study the free vibration characteristics of
unstiffened cylindrical shell. The Love-Timoshenko formulation for the strain
energy is used in conjunction with Hamilton's principle to compute the natural
propagation constants for two shell geometries and different circumferential
nodal patterns employing Floquet's principle. The natural frequencies were
obtained using Sengupta's method and were compared with those obtained from
classical Arnold-Warburton's method. The results from the wave propagation
method were found to compare identically with the classical methods, since both
the methods lead to the exact solution of the same problem. Thus consideration
of the shell segment between two consecutive nodal points as a periodic
structure is validated. The variations of the phase constants at the lower
bounding frequency for the first propagation band for different nodal patterns
have been computed. The method is highly computationally efficient.
