C. T. F. Ross

Bio: C. T. F. Ross is an academic researcher. The author has contributed to research in topics: Vibration & Cylinder (engine). The author has an hindex of 1, co-authored 1 publications receiving 49 citations.

Finite elements for the vibration of cones and cylinders

Abstract: Elemental mass matrices have been produced for the vibration of conical and cylindrical shells, based on a semi-analytical approach. Frequencies and modes of vibration have been compared with existing solutions and also with experimental results obtained from other sources. Good agreement has been found between theory and experiment for thin-walled circular cylinders and cones, a cone-cylinder combination, and a cooling tower model. A theoretical investigation was also made on the vibration of a circular cylinder when subjected to uniform pressure.

Non-Linear Vibrations of Shell-Type Structures: a Review with Bibliography

Abstract: The aim of this paper is to provide a contemporarily relevant survey of studies on non-linear vibrations of shell-type structures. The effects of geometrical non-linearity, and specific difficulties encountered in non-linear dynamic analysis of shell-type structures are presented and discussed. Studies on non-linear vibrations of shells are categorized by different shell configurations (shapes) in a chronological order. Also, the most commonly used methods of modelling and solution are reviewed and commented. Published reviews on non-linear vibrations of shell-type structures including complicating effects of anisotropy, initial stress, added mass, elastic foundation, stiffeners, open geometry (singly and doubly curved), transverse shear deformations, torsion, and interaction with fluid are also surveyed. Comments on the previous non-linear works are presented and some orientations for future research are suggested. Another purpose of this paper is to provide engineers, scientists and researchers with a list of 175 references, which should be very useful for locating relevant existing literature quickly.

Vibration analysis of laminated conical shells with variable thickness

Abstract: Effects of thickness variation on natural frequencies of laminated conical shells have been studied by using a semi-analytical finite element method. Love's first approximation thin shell theory is used to solve the problem. Effects of various parameters, such as the number of layers of the shell, the semi-vertex angle, the slant length to small end radius ratio and the thickness variation parameter (maximum to minimum thickness ratio), are studied, particularly on the lowest natural frequency. Shells of linear symmetrically varying thickness, about the mid-length of the shell, have been considered for the analyis. During the computation, the mass of the shell was kept constant for a particular slant length to small end radius ratio in order to provide useful examples of the effect of the thickness distribution on the natural frequencies.

Free vibration of circular cylindrical shells with axially varying thickness

Abstract: A semi-analytical finite element analysis is presented for determining the natural frequencies of thin circular isotropic cylindrical shells with variable thickness. Love's first approximation shell theory is used to solve the problem. The effect of thickness distribution on natural frequencies was determined for two boundary conditions; viz., simply supported-simply supported and clamped-clamped with different length to radius ratios. The thickness distribution was assumed to be linear and quadratic along the axial direction.

Calculation of natural frequencies and vibration modes of variable thickness cylindrical shells using the Wittrick-Williams algorithm

Abstract: Dynamic stiffness equations are formulated for variable thickness cylindrical shells, under the assumptions of Donnell, Timoshenko and Flugge theories. Transcendental dynamic stiffness matrices are formed by solving numerically the governing eighth order differential equations using the boundary-value solver COLSYS. Undamped natural frequencies are found using the Wittrick-Williams algorithm. The shell is divided into smaller elements whose clamped end natural frequencies exceed the highest frequency of interest. A parametric study examines the effects of varying the geometry, degree of thickness taper and end conditions on the natural frequencies and mode shapes, providing benchmark results for designers and future researchers.

Vibration analysis of orthotropic shells with variable thickness

Abstract: The free vibration characteristics of orthotropic circular cylindrical shells are analysed using Love's first approximation shell theory. Semianalytical finite element method is used as the method of solution. Shells of clamped-clamped and simply supported-simply supported boundary conditions are analysed with thickness varying along the axial direction. The influence of thickness distribution on natural frequencies, especially on lowest natural frequency, is studied. The effect of degree of orthotropy on natural frequencies of shells is also investigated.