Response of Cylindrical Shells to Moving Loads

1964 ◽  
Vol 31 (1) ◽  
pp. 105-111 ◽  
Author(s):  
J. P. Jones ◽  
P. G. Bhuta
Keyword(s):  
Cylindrical Shell ◽  
Constant Velocity ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Moving Loads ◽  
Coupling Effects ◽  
Influence Coefficients ◽  
Pressure Pulses

The response of a circular cylindrical shell subjected to a moving ring load with a constant velocity has been examined in detail when both longitudinal and transverse coupling effects are included. It is found that the correction in the bending resonance velocity resulting from the inclusion of longitudinal coupling effects is small. The results of the analysis may be used as influence coefficients to determine, by means of Duhamel integrals, the displacements and stresses produced by varying pressure pulses.

Buckling of Stiffened Curved Panels and Cylindrical Shells: A Study of Comparison Among Various Theories

2012 ◽  
Author(s):  
S. Harutyunyan ◽  
D. J. Hasanyan ◽  
R. B. Davis
Keyword(s):  
Cylindrical Shell ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Laminated Composite ◽  
Physical Parameters ◽  
Buckling Loads ◽  
Isotropic Cylindrical Shell ◽  
Analytical Formulas ◽  
Laminated Composite Shells ◽  
Curved Panels

Formulation is derived for buckling of the circular cylindrical shell with multiple orthotropic layers and eccentric stiffeners acting under axial compression, lateral pressure, and/or combinations thereof, based on Sanders-Koiter theory. Buckling loads of circular cylindrical laminated composite shells are obtained using Sanders-Koiter, Love, and Donnell shell theories. These theories are compared for the variations in the stiffened cylindrical shells. To further demonstrate the shell theories for buckling load, the following particular case has been discussed: Cross-Ply with N odd (symmetric) laminated orthotropic layers. For certain cases the analytical buckling loads formula is derived for the stiffened isotropic cylindrical shell, when the ratio of the principal lamina stiffness is F = E2/E1 = 1. Due to the variations in geometrical and physical parameters in theory, meaningful general results are complicated to present. Accordingly, specific numerical examples are given to illustrate application of the proposed theory and derived analytical formulas for the buckling loads. The results derived herein are then compared to similar published work.

Free Asymmetric Vibrations of Composite Full Circular Cylindrical Shells Stiffened by a Bonded Central Shell Segment

2004 ◽  
Author(s):  
U. Yuceoglu ◽  
V. O¨zerciyes
Keyword(s):  
Cylindrical Shell ◽  
Shell Theory ◽  
Natural Frequencies ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Adhesive Layer ◽  
Shear Stresses ◽  
First Order ◽  
Stress Resultant ◽  
Circular Cylindrical Shells

This study is concerned with the “Free Asymmetric Vibrations of Composite Full Circular Cylindrical Shells Stiffened by a Bonded Central Shell Segment.” The base shell is made of an orthotropic “full” circular cylindrical shell reinforced and/or stiffened by an adhesively bonded dissimilar, orthotropic “full” circular cylindrical shell segment. The stiffening shell segment is located at the mid-center of the composite system. The theoretical analysis is based on the “Timoshenko-Mindlin-(and Reissner) Shell Theory” which is a “First Order Shear Deformation Shell Theory (FSDST).” Thus, in both “base (or lower) shell” and in the “upper shell” segment, the transverse shear deformations and the extensional, translational and the rotary moments of inertia are taken into account in the formulation. In the very thin and linearly elastic adhesive layer, the transverse normal and shear stresses are accounted for. The sets of the dynamic equations, stress-resultant-displacement equations for both shells and the in-between adhesive layer are combined and manipulated and are finally reduced into a ”Governing System of the First Order Ordinary Differential Equations” in the “state-vector” form. This system is integrated by the “Modified Transfer Matrix Method (with Chebyshev Polynomials).” Some asymmetric mode shapes and the corresponding natural frequencies showing the effect of the “hard” and the “soft” adhesive cases are presented. Also, the parametric study of the “overlap length” (or the bonded joint length) on the natural frequencies in several modes is considered and plotted.

Stability of Cylindrical Shells Under Moving Loads by the Direct Method of Liapunov

1967 ◽  
Vol 34 (4) ◽  
pp. 991-998 ◽  
Author(s):  
G. A. Hegemier
Keyword(s):  
Constant Velocity ◽  
Local Stability ◽  
Shell Theory ◽  
Circular Cylindrical Shell ◽  
Direct Method ◽  
Sufficient Conditions ◽  
Functional Space ◽  
Moving Loads ◽  
The Stability ◽  
Shell Axis

The stability of a long, thin, elastic circular cylindrical shell subjected to axial compression and an axisymmetric load moving with constant velocity along the shell axis is studied. With the aid of the direct method of Liapunov, and employing a nonlinear Donnell-type shell theory, sufficient conditions for local stability of the axisymmetric response are established in a functional space whose metric is defined in an average sense. Numerical results, which are presented for the case of a moving decayed step load, reveal that the sufficient conditions for stability developed here and the sufficient conditions for instability obtained in a previous paper lead to the actual stability transition boundary.

Experimental Study on Pre-Stressed Circular Cylindrical Shell

2012 ◽  
Author(s):  
Antonio Zippo ◽  
Marco Barbieri ◽  
Matteo Strozzi ◽  
Vito Errede ◽  
Francesco Pellicano
Keyword(s):  
Experimental Study ◽  
Cylindrical Shell ◽  
Axial Load ◽  
Nonlinear Vibrations ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Experimental Studies ◽  
Element Model ◽  
Experimental Setup ◽  
Circular Cylindrical Shells

In this paper an experimental study on circular cylindrical shells subjected to axial compressive and periodic loads is presented. Even though many researchers have extensively studied nonlinear vibrations of cylindrical shells, experimental studies are rather limited in number. The experimental setup is explained and deeply described along with the analysis of preliminary results. The linear and the nonlinear dynamic behavior associated with a combined effect of compressive static and a periodic axial load have been investigated for different combinations of loads; moreover, a non stationary response of the structure has been observed close to one of the resonances. The linear shell behavior is also investigated by means of a finite element model, in order to enhance the comprehension of experimental results.

scholarly journals Instability of Cylindrical Shells Subjected to Axisymmetric Moving Loads

1966 ◽  
Vol 33 (2) ◽  
pp. 289-296 ◽  
Author(s):  
G. A. Hegemier
Keyword(s):  
Cylindrical Shell ◽  
Constant Velocity ◽  
Broad Class ◽  
Infinite Length ◽  
Functional Difference ◽  
Moving Loads ◽  
Loading Function ◽  
Double Laplace Transform ◽  
Special Cases ◽  
The Stability

Using a Donnell-type nonlinear theory and the stability in the small concept of Poincare´, the instability of an infinite-length cylindrical shell subjected to a broad class of axisymmetric loads moving with constant velocity is studied. Special cases of the general loading function include the moving-ring, step, and decayed-step loads. The analysis is carried out with a double Laplace transform, functional-difference technique. Numerical results are presented for the case of the moving-ring load.

Bending of Cord Composite Laminate Cylindrical Shells

2003 ◽  
Vol 70 (3) ◽  
pp. 364-373 ◽  
Author(s):  
A. J. Paris ◽  
G. A. Costello
Keyword(s):  
Cylindrical Shell ◽  
Differential Equations ◽  
Closed Form ◽  
Composite Laminate ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Axisymmetric Loading ◽  
Shell Axis

A theory for the bending of cord composite laminate cylindrical shells is developed. The extension-twist coupling of the cords is taken into account. The general case of a circular cylindrical shell with cord plies at various angles to the shell axis is considered. The differential equations for the displacements are derived. These equations are solved analytically in closed form for a shell subjected to axisymmetric loading and no in-plane tractions. The results of the current study are compared with the commonly used Gough-Tangorra and Akasaka-Hirano solutions.

A Theoretical Study of the Elastic Behavior of Two Normally Intersecting Cylindrical Shells

1969 ◽  
Vol 91 (3) ◽  
pp. 563-572 ◽  
Author(s):  
J. W. Hansberry ◽  
N. Jones
Keyword(s):  
Cylindrical Shell ◽  
Theoretical Study ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Bending Moment ◽  
Pressure Vessels ◽  
Numerical Results ◽  
Elastic Behavior ◽  
Cylinder Diameter ◽  
Plane Transverse

A theoretical study has been made into the elastic behavior of a joint formed by the normal intersection of a right circular cylindrical shell with another of larger diameter. The wall of the larger cylinder is assumed to remain open inside the joint in order to give an arrangement which is encountered frequently in pressure vessels or pipeline intersections. An external bending moment which acts in the plane of the joint is applied to the nozzle cylinder and is equilibriated by moments of half this magnitude applied to either end of the parent cylinder. A solution for this loading has been obtained by assuming antisymmetric distributions of certain stresses across a plane transverse to the joint. The analysis presented is believed to be valid for nozzle to cylinder diameter ratios of less than 1:3. Numerical results are given for a number of cases having radius ratios of 1:10 and 1:4.

Extending Koiter’s Simplified Equations to Shells of Arbitrary Closed Cross Section

2005 ◽  
Vol 73 (4) ◽  
pp. 709-711
Author(s):  
James G. Simmonds
Keyword(s):  
Cylindrical Shell ◽  
Energy Density ◽  
Error Estimate ◽  
Cross Section ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Equilibrium Equations ◽  
Pointwise Error

The techniques used by Koiter in 1968 to derive a simplified set of linear equilibrium equations for an elastically isotropic circular cylindrical shell in terms of displacements and the associated pointwise error estimate engendered in Love’s uncoupled strain-energy density are here extended to derive analogous simplified equilibrium equations and an error estimate for elastically isotropic cylindrical shells of arbitrary closed cross section.

Bending of Cord Composite Cylindrical Shells

1999 ◽  
Vol 67 (1) ◽  
pp. 117-127 ◽  
Author(s):  
A. J. Paris ◽  
G. A. Costello
Keyword(s):  
Cylindrical Shell ◽  
Boundary Conditions ◽  
Analytical Method ◽  
Deformation Behavior ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Middle Surface ◽  
The Matrix ◽  
Shell Axis ◽  
Composite Cylindrical Shells

An analytical method for determining the load-deformation behavior of cord composite cylindrical shells is developed by considering the mechanics of the matrix, the cords, and the shell. To illustrate the method, a circular cylindrical shell with a single ply of uniformly spaced cords parallel to the shell axis is considered. The differential equations for the displacements are derived. These equations are solved analytically in closed form for a shell with the cords on the middle surface and subjected to axisymmetric loading. The deformations are strongly dependent upon the properties of the constituents, including the extension-twist coupling of the cords, and the geometry, boundary conditions, and loading. [S0021-8936(00)02701-X]

Experiments and Simulations in Travelling Wave and Non-Stationary Nonlinear Vibrations of Circular Cylindrical Shells

2016 ◽  
Author(s):  
Marco Amabili ◽  
Prabakaran Balasubramanian ◽  
Giovanni Ferrari
Keyword(s):  
Cylindrical Shell ◽  
Traveling Wave ◽  
Internal Resonance ◽  
Nonlinear Vibrations ◽  
Circular Cylindrical Shell ◽  
Cylindrical Shells ◽  
Excitation Amplitude ◽  
Added Mass ◽  
Travelling Wave ◽  
Wave Response

The nonlinear vibrations of a water-filled circular cylindrical shell subjected to radial harmonic excitation in the spectral neighborhood of the lowest resonances are investigated numerically and experimentally by using a seamless aluminum sample. The experimental boundary conditions are close to a simply supported circular cylindrical shell. Modal analysis reveals the presence of predominantly radial driven and companion modes in the low frequency range, implying the existence of a traveling wave phenomenon in the nonlinear field. Experimental studies previously carried out on cylindrical shells did not permit the complete identification of the characteristic traveling wave response and of its non-stationary nature. The added mass of the internal quiescent, incompressible and inviscid fluid results in an increase of the weakly softening behavior of the shell, as expected. The minimization of the added mass due to the excitation system and the negligible entity of the geometric imperfections of the shell allow the appearance of an exact one-to-one internal resonance between driven and companion modes. This internal resonance gives rise to a travelling wave response around the shell circumference and non-stationary, quasi-periodic vibrations, which are experimentally verified by means of stepped-sine testing with feedback control of the excitation amplitude. The same phenomenon is observed in the nonlinear response obtained numerically. The traveling wave is measured by means of state-of-the-art laser Doppler vibrometry applied to multiple points on the structure simultaneously. Previous studies present in literature did not show if this vibration can be chaotic for relatively small vibration amplitudes. Chaos is here observed in the frequency region where the travelling wave response is present for vibrations amplitudes smaller than the thickness of the shell. The relevant nonlinear reduced order model of the shell is based on the Novozhilov nonlinear shell theory retaining in-plane inertia and on an expansion of the displacements in terms of a properly chosen base of linear modes. An energy approach is used to obtain the nonlinear equations of motion, which are numerically studied (i) by using a code based on arc-length continuation and collocation method that allows bifurcation analysis in case of stationary vibrations, (ii) by a continuation code based on direct integration and Poincaré maps, which also evaluates the maximum Lyapunov exponent in case of non-stationary vibrations. The comparison of experimental and numerical results is particularly satisfactory throughout the various excitation amplitude levels considered. The two methods concur in describing the progressive development of the companion mode into a fully developed traveling wave and the subsequent appearance of quasi-periodic and eventually chaotic vibrations.

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