Dynamic Buckling of a Damped Externally Pressurized Imperfect Cylindrical Shell

1979 ◽  
Vol 46 (2) ◽  
pp. 372-376 ◽  
Author(s):  
D. F. Lockhart

The dynamic buckling of a finite damped imperfect circular cylindrical shell which is subjected to step-loading in the form of lateral or hydrostatic pressure is examined by means of a perturbation method. The imperfection is assumed to be small. An asymptotic expression for the dynamic buckling load is obtained in terms of the damping coefficient and the Fourier component of the imperfection in the shape of the classical buckling mode. A simple relation which is independent of the imperfection is then obtained between the static and dynamic buckling loads.

1975 ◽  
Vol 42 (2) ◽  
pp. 316-320 ◽  
Author(s):  
D. Lockhart ◽  
J. C. Amazigo

The dynamic buckling of imperfect finite circular cylindrical shells subjected to suddenly applied and subsequently maintained lateral or hydrostatic pressure is studied using a perturbation method. The geometric imperfections are assumed small but arbitrary. A simple asymptotic expression is obtained for the dynamic buckling load in terms of the amplitude of the Fourier component of the imperfection in the shape of the classical buckling mode. Consequently, for small imperfection, there is a simple relation between the dynamic buckling load under step-loading and the static buckling load. This relation is independent of the shape of the imperfection.


Author(s):  
S. Harutyunyan ◽  
D. J. Hasanyan ◽  
R. B. Davis

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.


2001 ◽  
Author(s):  
Anthony N. Kounadis

Abstract Nonlinear dynamic buckling of one-degree-of freedom (1-DOF) undamped systems under step loading (autonomous systems) of constant direction and infinite duration is discussed in detail using Catastrophe Theory. Attention is focused on the relation of static cuspoind catastrophes to the corresponding dynamic catastrophes for 1-DOF autonomous undamped systems by determining properly the dynamic singularity and bifurcational sets for such systems. Using local analysis one has to classify first the total potential energy (TPE) function of the system into one of the elementary Thom’s catastrophes by defining the corresponding control (unfolding) parameters. Subsequently, using global analyses one can readily obtain exact results for the dynamic buckling loads (DBLs) and their imperfection sensitivity of systems subjected to dynamic dual cusp and tilted cusp catastrophes. It was found that the maximum DBL of the dynamic tilted cusp catastrophe corresponds to a limit point lying in the vicinity of the hysteresis point (related to the static tilted cusp catastrophe). Numerical examples illustrate the methodology proposed herein.


2010 ◽  
Vol 10 (03) ◽  
pp. 411-439 ◽  
Author(s):  
YONG-LIN PI ◽  
MARK ANDREW BRADFORD ◽  
SHUGUO LIANG

Performing a dynamic buckling analysis of structures is more difficult than carrying out its static buckling analysis counterpart. Some structures have a nonlinear primary equilibrium path including limit points and an unstable equilibrium path. They may also have bifurcation points at which equilibrium bifurcates from the primary equilibrium path to an unstable secondary equilibrium path. When such a structure is subjected to a load that is applied suddenly, the oscillation of the structure may reach the unstable primary or secondary equilibrium path and the structure experiences an escaping-motion type of buckling. For these structures, complete solutions of the equations of motion are usually not needed for a dynamic buckling analysis, and what is really sought are the critical states for buckling. Nonlinear dynamic buckling of an undamped two degree-of-freedom arch model is investigated herein using an energy approach. The conditions for the upper and lower dynamic buckling loads are presented. The merit of the energy approach for dynamic buckling is that it allows the dynamic buckling load to be determined without the need to solve the equations of motion. The solutions are compared with those obtained by an equation of motion approach.


1973 ◽  
Vol 40 (3) ◽  
pp. 736-740 ◽  
Author(s):  
C. A. Fisher ◽  
C. W. Bert

As an exploratory effort toward improving the crashworthiness of light aircraft cabins, a theoretical analysis was made to predict the dynamic buckling load and buckling time of a stiffened, thin-walled circular cylindrical shell. To provide for the large stiffener spacing in light aircraft, the stiffeners were considered as discrete elements by means of a Dirac delta procedure. The nonlinear governing equations were derived using Hamilton’s principle and the final equations were obtained by means of Galerkin’s method. Solution was carried out by using a Gauss-Jordan technique on the algebraic equations and a Runge-Kutta technique on the nonlinear differential equations. Numerical results are presented for an idealized model of a typical light aircraft cabin.


Author(s):  
Jia-Bin Sun ◽  
Xin-Sheng Xu ◽  
Chee-Wah Lim

AbstractIn this paper, the dynamic buckling of an elastic cylindrical shell subjected to an axial impact load is analyzed in Hamiltonian system. By employing a symplectic method, the traditional governing equations are transformed into Hamiltonian canonical equations in dual variables. In this system, the critical load and buckling mode are reduced to solving symplectic eigenvalues and eigensolutions respectively. The result shows that the critical load relates with boundary conditions, thickness of the shell and radial inertia force. And the corresponding buckling modes present some local shapes. Besides, the process of dynamic buckling is related to the stress wave, the critical load and buckling mode depend upon the impacted time. This paper gives analytically and numerically some new rules of the buckling problem, which is useful for designing shell structures.


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