We present an idealised model of gravitational collapse, describing a collapsing rotating cylindrical shell of null dust in flat space, with the metric of a spinning cosmic string as the exterior. We find that the shell bounces before closed timelike curves can be formed. Our results also suggest slightly different definitions for the mass and angular momentum of the string. Introduction A stat...

A new method for obtaining the response of a baaed, uid{loaded, nite cylindrical shell using the nite element method is presented. The Galerkin nite element formulation for this problem utilizes a Neumann Green's function representation of the pressure loading on the shell. By representing the pressure loading in this manner, only the structure need be discretized. Both C 0 and C 1 nite element...

Cylindrical shells, unstiffened or stiffened with rings and/or stringers are commonly used in offshore structures as main loading-carrying members. Comprehensive theoretical work and experimental studies on the buckling behavior of cylindrical shells have been carried out in the past. The increasing offshore application of stiffened cylindrical shells has raised some new challenges that need to...

Abstract In this contribution a brief overview of the development of an orthotropic material model for the simulation of clear spruce wood under simultaneous biaxial in-plane stresses and transverse shear stresses is given. The model considers an initially linear elastic domain as well as hardening and softening behaviour at higher states of stress and strain, respectively. Combining the advant...

In this study, the free vibration of partially fluid-filled laminated composite circular cylindrical shell with arbitrary boundary conditions has been investigated by using Rayleigh-Ritz method. The analysis has been carried out with strain-displacement relations based on Love’s thin shell theory and the contained fluid is assumed irrotational, incompressible and inviscid. After determining the...

the produced electric and magnetic fields due to lightning strikes to mountainous ground are determined in this paper. for the sake of simplicity a cone-shaped ground with finite conductivity is assumed to represent a natural nonflat ground. by this assumption, we deal with an axillary symmetrical structure so we use the cylindrical 2d-fdtd to save the simulation memory and time, dramatically. ...

Article history: Received: 04.09.2013. Received in revised form: 20.09.2013. Accepted: 02.10.2013. This paper presents a linear cellular automation (LCA) method for predicting the dynamic failure (DF) mode of both single-layer latticed shell and single-layer cylindrical latticed shell subjected to ground motions. The LCA model of the shell obtains the state values of cells/nodes including the n...

For cylindrical shell gyroscopes, node position of their operating eigenmodes has an important influence on the gyroscopes' performance. It is considered that the nodes are equally separated from each other by 90° when the resonator vibrates in the standing wave eigenmode. However, we found that, due to manufacturing errors and trimming, the nodes may not be equally distributed. This paper main...

The paper introduces a new alternative towards fabrication of auxetic metamaterials (materials with negative Poisson’s ratio) controlled by geometric transformations. These transformations are derived from the theory of small (infinitesimal) elastic deformation superimposed on finite elastic deformations. By using this theory, a cylindrical region filled with initial deformed foam is transforme...

We investigate the twofold functionality of a cylindrical shell consisting of a negatively refracting heterogeneous bianisotropic (NRHB) medium deduced from geometric transforms. The numerical simulations indicate that the shell enhances their scattering by a perfect electric conducting (PEC) core, whereas it considerably reduces the scattering of electromagnetic waves by closely located object...