33 research outputs found
Aspects of topology of condensates and knotted solitons in condensed matter systems
The knotted solitons introduced by Faddeev and Niemi is presently a subject
of great interest in particle and mathematical physics. In this paper we give a
condensed matter interpretation of the recent results of Faddeev and Niemi.Comment: v2: Added a reference to the paper E. Babaev, L.D. Faddeev and A.J.
Niemi cond-mat/0106152 where an exact equivalence was shown between the
two-condensate Ginzburg-Landau model and a version of Faddeev model.
Miscelaneous links related to knotted solitons are available at the author
homepage at http://www.teorfys.uu.se/PEOPLE/egor/ . Animations of knotted
solitons by Hietarinta and Salo are available at
http://users.utu.fi/h/hietarin/knots/c45_p2.mp
Implementation and Validation of Schapery-Rand Anisotropic Viscoelasticity Model for Super-Pressure Balloons
The thin film used for the NASA Ultra Long Duration Balloons (ULDB) shows con-siderable time-dependent behaviour. Furthermore, experiments on scaled ULDB balloons have revealed that wrinkles are present over a wide range of pressures. A numerical model has been developed describing the nonlinear anisotropic viscoelastic material behaviour by means of a Schapery-type model and this model has been extended to model wrinkling by means of a user-defined subroutine in the finite-element package ABAQUS. After a description of the viscoelastic modelling approach, a lobe of a 48 gore ULDB flat facet balloon is modelled and compared to experimental results. Additionally two test cases of anisotropic wrinkling are presented, one involving a flat membrane and one a cylindrical balloon structure. I
UNRESOLVED PROBLEMS IN POLYMERIC ANELASTICITY
No abstract availabl