Stress-strain state of the surface of a circular cylindrical shell under the action of acoustic waves

We present the results of an investigation of the stress-strains state of a mechanical system consisting of two coaxial circular cylinders connected by an elastic link under the action of external acoustic pressure waves. We establish regularities of the appearance of displacements of the elements of the surface of the circular cylinders and the characteristics of the state of the entire mechanical system under acoustic loading. Translated from Problemy Prochnosti, No. 3, pp. 139–144, May–June, 1997.     

Torsion of an infinite composite elastic cylindrical shell

Summary The problem considered is that of the torsion of a semi-infinite composite elastic cylindrical shell composed of two materials of different rigidity modulus. It is assumed that there is perfect bonding at the common cylindrical surface. The problem is solved by means of the use of Fourier transforms.     

Looping post-buckling paths of an axially loaded elastic cylindrical shell

We present first-order and second-order iteration solutions to the Donnell cylinder equations for the post-buckling response of an axially loaded elastic cylindrical shell. Both solutions possess looping equilibrium paths with a remote bifurcation point, a feature inaccessible to standard linear perturbation analysis. The implication of this result for linear perturbation theory is discussed.     

Strain growth of the in-plane response in an elastic cylindrical shell

Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading. The local elastic response of the vessel may become larger in a later stage compared to its response in the initial stage. To find out the possible mechanisms of the strain growth phenomenon, the in-plane response of an elastic cylindrical shell subjected to an internal blast loading is investigated. Vibration frequencies of membrane modes and bending modes are calculated theoretically and numerically. The dynamic non-linear in-plane responses of an elastic cylindrical shell subjected to internal impulsive loading are studied by theoretical analysis and finite-element simulation using LS-DYNA. It is shown that the coupling between the membrane breathing mode and flexural bending modes is the primary cause of strain growth in this problem. The first peak strain of the breathing mode and the ratio of the thickness to the radius are the dominant factors determining the occurrence of strain growth. Other mechanisms, which have been suggested in previous studies (e.g. beating between vibration modes with close frequencies, interactions between multiple vibration modes, resonance between vessel vibration and reflected blast wave, influence of structural perturbations), are secondary causes for the occurrence of the strain growth phenomenon in the studied problem.     

Solution of problems on the stress state of an elastic medium with an inhomogeneous orthotropic cylindrical inclusion

A numerical-and-analytical approach to the investigation of the stress state of an elastic medium with an inhomogeneous cylindrical inclusion is proposed. The stress state is presented as a superposition of two state—the main state written in the analytical form and the disturbed one determined using analytical procedures and a numerical method. The stress state in the vicinity of the hollow cylindrical inclusion is analyzed. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev, Ukraine. Translated from Problemy Prochnosti, No. 4, pp. 48–58, July–August, 1999.     

Special features of the state of stress and strain of plates with finite dimensions under acoustic load

The article presents a comparative qualitative and quantitative analysis of the state of stress and strain of the surface of a flat isotropic plate under acoustic load for three cases of state of stress and strain: space-frequency resonance, incomplete space-frequency resonance, and frequency resonance.Translated from Problemy Prochnosti, No. 10, pp. 93–96, October, 1990.     

The transient response of a two-layered elastic cylindrical shell impinged by an underwater shock wave

The governing equations of a two-layered circular cylindrical shell have been derived. A recently developed theoretical approximation, the reflected-afterflow-virtual-source (RAVS) model was applied to determine the fluid–structure interaction. Cases of two-layered infinitive length elastic cylindrical shell impinged by planar shock waves were investigated by using finite difference method. Results by using this model were compared to those by using the software USA/LSDYNA3D, and they are in good agreement. Some parametric studies were done to study the effect of the Young's modulus E_i and thickness h_i of the structure on the transient responses of the shell.     

Deformations in an infinite cylindrical shell restrained by elastic or rigid walls

Summary The contact problem of an infinite cylindrical shell with an elastic or a rigid foundation is investigated. A shear deformation non-linear shell theory is used in setting up the governing differential equations and the functional of total potential energy. The variations of contact pressure and domains are discussed for different shell parameters, friction and rigidity coefficients of foundation. The obtained results are compared with the results for geometrically linear shell theory. Some problems connected with the variational inequality formulation of the analysed unilateral boundary problem are also discussed.With 7 Figures     

Dynamic response of an FGM cylindrical shell under moving loads

This paper presents an analytical study on the dynamic behavior of the infinitely-long, FGM cylindrical shell subjected to combined action of the axial tension, internal compressive load and ring-shaped compressive pressure with constant velocity. It is assumed that the cylindrical shell is a mixture of metal and ceramic that its properties changes as a function of the shell thickness. The problem is studied on the basis of the theory of vibrations of cylindrical shells. Derived formulas for the maximum static and dynamic displacements, dynamic factors and critical velocity for the FGM cylindrical shell subjected to moving loads. Numerical calculations have been made for fully metal, fully ceramic and FGM (Si₃N₄/SUS304) cylindrical shells. A parametric study is conducted to demonstrate the effects of the material property gradient, the radius to thickness ratio and the velocity of the moving load on the dynamic displacements and dynamic factors of the inner and ring-shaped pressures for FGM cylindrical shells.