this research deals with axial and oblique impact crash tests on simple and hybrid composite tubes. axial and oblique impact tests have been generated on simple and hybrid composite tubes with one, two and three layers. a drop test rig was used to conduct the experiments. furthermore, in order to gain more detailed knowledge about the crash process, finite element simulations of the experiments...

The results of a numerical study of the nonlinear response of thin unstiffened aluminum cylindrical shells with a longitudinal crack are presented. The shells are analyzed with a nonlinear shell analysis code that accurately accounts for global and structural response phenomena. The effects of initial crack length on the prebuckling, buckling and postbuckling responses of a typical shell subjec...

Abstract In this article, the nonlinear dynamic responses of sandwich functionally graded (FG) porous cylindrical shell embedded in elastic media are investigated. The studied here consists three layers, which outer and inner skins made solid metal, while core is FG metal foam. Partial differential equations derived by utilizing improved Donnell’s theory Hamilton’s principle. Afterwards, Galerk...

The transmission coefficient for vibrational waves crossing an abrupt junction between two thin elastic plates of different widths is calculated. These calculations are relevant to ballistic phonon thermal transport at low temperatures in mesoscopic systems and the Q for vibrations in mesoscopic oscillators. Complete results are derived in a simple scalar model of the elastic waves, and results...

In this paper, natural frequency and response of forced vibration of composite laminated conical shells under different boundary conditions are investigated. To this end, equations of Donnell's thin shell theory are used as governing equations. The analytical Galerkin method together with beam mode shapes as weighting functions is employed to solve the problem. Due to importance of boundary con...

In this work the equations of motion of a Solid State Wave Gyroscope (SWG) with rotary thin cylindrical shell resonator is analyzed using the shell and plates elasticity theory. The gyroscope conversion factor found in this analytical study corresponds with the experimental results obtained and listed in the References. The function of the SWG to measure the angular velocity or the rotating ang...

The generalized Darmois–Israel formalism for Einstein–Gauss–Bonnet theory is applied to construct thin-shell Lorentzian wormholes with spherical symmetry. We calculate the energy localized on the shell, and we find that for certain values of the parameters wormholes could be supported by matter not violating the energy conditions.

The subject of this paper is the study of the asymptotic behaviour of the equilibrium configurations of a nonlinearly elastic thin rod, as the diameter of the cross-section tends to zero. Convergence results are established assuming physical growth conditions for the elastic energy density and suitable scalings of the applied loads, that correspond at the limit to different rod models: the cons...

The nonlinear axisymmetric post-buckling behaviour of perfect, thin, elastic spherical shells subject to external pressure and their asymmetric bifurcations are characterized, providing results for a structure/loading combination with an exceptionally nonlinear buckling response. Immediately after the onset of buckling, the buckling mode localizes into a dimple at the poles. The relations among...