scholarly journals On The Modified Orthogonal Frame with Curvature and Torsion in 3-Space

2016 ◽  
Vol 4 (1) ◽  
pp. 184-188 ◽  
Author(s):  
Bahaddin BÜKCÜ ◽  
Murat Kemal KARACAN
2021 ◽  
Vol 21 (2) ◽  
pp. 385-394
Author(s):  
AYŞE ZEYNEP AZAK

In this paper, the involute-evolute curve concept has been defined according to two type modified orthogonal frames at non-zero points of curvature and torsion in the Euclidean space E^3 , respectively. Later, the characteristic theorems related to the distance between the corresponding points of these curves have been given. Besides, the relations have been found between the curvatures and also torsions of the two type the involute-evolute modified orthogonal pairs.


2021 ◽  
Author(s):  
STEPAN V. LOMOV ◽  
JEONYOON LEEJEONYOON LEE ◽  
BRIAN L. WARDLE ◽  
NIKITA A. GUDKOV ◽  
ISKANDER S. AKHATOV ◽  
...  

The paper considers nanocomposites, reinforced with aligned carbon nanotubes (A- CNTs). Nominally aligned, the CNTs in the forest are wavy, which has important consequences in downgraded mechanical properties, and influences electric and thermal performance. The most detailed geometrical model of A-CNTs was proposed by Stein and Wardle (Nanotechnology, 27:035701, 2015). It creates a centerline trajectory of a CNT in steps, each step defining a section of the CNT, growing in the alignment direction with certain deviations. The paper, starting from this framework, formulates a model of the CNT geometry, which is based on the concept of correlation length of the CNT waviness and maximum admissible CNT curvature and torsion. The value of the maximum curvature can be linked to the buckling criteria for CNTs, or derived from ab initio and finite element modelling. It is used as a limiting factor for the growth, defining the waviness and tortuosity of the CNTs. The CNTs in the forest are placed in a random non-regular way, using Voronoi tessellation. The full paper includes investigation of the proposed algorithm for several values of the CNT volume fraction (in the range 0.5%…8%), the dependency of the modelled geometry on the curvature, and the apparent twist of the CNT centerlines. The modelling results are compared with experimental observations in 3D TEM imaging.


2018 ◽  
Vol 43 (4) ◽  
pp. 1905-1916 ◽  
Author(s):  
Mohamd Saleem Lone ◽  
Hasan ES ◽  
Murat Kemal Karacan ◽  
Bahaddin Bukcu
Keyword(s):  

2005 ◽  
Vol 42 (5) ◽  
pp. 387-397 ◽  
Author(s):  
S. Litster ◽  
J. G. Pharoah ◽  
N. Djilali

2011 ◽  
Vol 20 (12) ◽  
pp. 1723-1739 ◽  
Author(s):  
J. S. AVRIN

The subject is a localized disturbance in the form of a torus knot of an otherwise featureless continuum. The knot's topologically quantized, self-sustaining nature emerges in an elementary, straightforward way on the basis of a simple geometric model, one that constrains the differential geometric basis it otherwise shares with General Relativity (GR). Two approaches are employed to generate the knot's solitonic nature, one emphasizing basic differential geometry and the other based on a Lagrangian. The relationship to GR is also examined, especially in terms of the formulation of an energy density for the Lagrangian. The emergent knot formalism is used to derive estimates of some measurable quantities for a certain elementary particle model documented in previous publications. Also emerging is the compatibility of the torus knot formalism and, by extension, that of the cited particle model, with general relativity as well as with the Dirac theoretic notion of antiparticles.


2007 ◽  
Vol 22 (29) ◽  
pp. 5237-5244 ◽  
Author(s):  
H. T. NIEH

Curvature and torsion are the two tensors characterizing a general Riemannian space–time. In Einstein's general theory of gravitation, with torsion postulated to vanish and the affine connection identified to the Christoffel symbol, only the curvature tensor plays the central role. For such a purely metric geometry, two well-known topological invariants, namely the Euler class and the Pontryagin class, are useful in characterizing the topological properties of the space–time. From a gauge theory point of view, and especially in the presence of spin, torsion naturally comes into play, and the underlying space–time is no longer purely metric. We describe a torsional topological invariant, discovered in 1982, that has now found increasing usefulness in recent developments.


1965 ◽  
Vol 22 (3) ◽  
pp. 471-479 ◽  
Author(s):  
Robert Betchov

We consider a very thin vortex filament in an unbounded, incompressible and inviscid fluid. The filament is not necessarily plane. Each portion of the filament moves with a velocity that can be approximated in terms of the local curvature of the filament. This approximation leads to a pair of intrinsic equations giving the curvature and the torsion of the filament, as functions of the time and the arc length along the filament. It is found that helicoidal vortex filaments are elementary solutions, and that they are unstable.The intrisic equations also suggest a linear mechanism that tends to produce concentrated torsion and a non-linear mechanism tending to disperse such singularities.


1985 ◽  
Vol 52 (3) ◽  
pp. 529-532 ◽  
Author(s):  
D. D. Sayers ◽  
M. C. Potter

Traditional analysis treats the helix as a straight wire with the effects of nonuniform heating, torsion, and large curvature ignored. Using a helical coordinate system the governing partial differential equation including these effects is derived. The equation is then solved numerically using the finite element method. The results indicate a strong dependence of the temperature on the torsion parameter when the curvature parameter is significant. As the curvature parameter increases, the temperature distribution becomes skew-symmetric and the maximum temperature in the helix increases. Nonuniform heating influences the temperature distribution independent of the curvature and torsion.


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