We study the dynamics of false vacuum bubbles in the Brans-Dicke theory of gravity by using the thin shell or thin wall approximation. We consider a false vacuum bubble that has a different value for the Brans-Dicke field between the inside false vacuum region and the outside true vacuum region. Within a certain limit of field values, the difference of field values makes the effective tension o...

The applicability and limitations of simplified models thin elastic circular cylindrical shells for linear vibrations double-walled carbon nanotubes (DWCNTs) are considered. models, which based on the assumptions membrane moment approximate thin-shell theories, compared with extended Sanders–Koiter shell theory. Actual discrete DWCNTs modelled by means couples concentric equivalent continuous t...

Most models of blown film extrusion are based on thin shell theory, which was first applied to these processes by Pearson and Petrie. There has been some contention in the literature as to the suitability of the thin shell model. More recently, Liu and coworkers presented an alternative quasi-cylindrical model that neglects longitudinal curvature but was reported to agree more closely with expe...

We summarize some recent results of the authors and their collaborators, regarding the derivation of thin elastic shell models (for shells with mid-surface of arbitrary geometry) from the variational theory of 3d nonlinear elasticity. We also formulate a conjecture on the form and validity of infinitely many limiting 2d models, each corresponding to its proper scaling range of the body forces i...

In this paper, we analyze a few physical characteristics of gravastar with cylindrical geometry in $f(R,T)$ theory, where $R$ is the Ricci scalar and $T$ trace energy-momentum tensor. The generally considered to be substitute black hole three different regions. present work, examine formulation gravastar-like structures theory. By using Darmois Israel matching conditions, formulate mass functio...

A thin shell finite element approach based on Loop’s subdivision surfaces is proposed, capable of dealing with large deformations and anisotropic growth. To this end, the Kirchhoff-Love theory of thin shells is derived and extended to allow for arbitrary in-plane growth. The simplicity and computational efficiency of the subdivision thin shell elements is outstanding, which is demonstrated on a...

The influence of wall elasticity on the response of a Helmholtz resonator is examined by analyzing the canonical case of a thin elastic spherical shell with a circular aperture subject o plane wave excitation. By neglecting the thickness of the wall and representing the elasticity via a "thin shell" theory the problem is reduced to one of solving an integral equation over the aperture for the p...