Using classical molecular dynamics and empirical potentials, we show that the axial deformation of single-walled carbon nanotubes is coupled to their torsion. The axial-strain-induced torsion is limited to chiral nanotubes-graphite sheets rolled around an axis that breaks its symmetry. Small strain behavior is consistent with chirality and curvature-induced elastic anisotropy (CCIEA)-carbon nan...

We introduce the torsional network model (TNM), an elastic network model whose degrees of freedom are the torsion angles of the protein backbone. Normal modes of the TNM displace backbone atoms including C(β) maintaining their covalent geometry. For many proteins, low frequency TNM modes are localized in torsion space yet collective in Cartesian space, reminiscent of hinge motions. A smaller nu...

BACKGROUND The cascade of events by which early diastolic left ventricular (LV) filling increases with exercise is not fully elucidated. Doppler tissue imaging (DTI) can detect myocardial motion, including torsion, whereas color M-mode Doppler (CMM) can quantify LV intraventricular pressure gradients (IVPGs). METHODS AND RESULTS Twenty healthy volunteers underwent echocardiographic examinatio...

Ultrasonic force microscopy (UFM) can be used to image the distribution of elastic modulus up to several tens of GPa, which is not possible by the force modulation mode using a soft cantilever of spring constant less than 1 N m‘. It was shown that by careful design of a piezoelectric transducer, together with a sample with small friction force, deflection vibration of the cantilever without tor...

This paper presents an improved model for naturally curved and twisted anisotropic beams with closed thin-walled cross-sections. By introducing eigenwarping functions and expanding axial displacements in series of eigenwarpings, the differential equation involving the generalized warping coordinate and the expression for eigenvalues can be derived using the principle of minimum potential energy...

Department of Engineering Physics, Department of Materials Science University of Wisconsin, 1500 Engineering Drive, Madison, WI 53706-1687, USA preprint adapted from Lakes, R. S., Reduced warp in torsion of reticulated foam due to Cosserat elasticity: experiment, Zeitschrift fuer Angewandte Mathematik und Physik (ZAMP), 67(3), 1-6 (2016). Abstract Warp of cross sections of square section bars i...

The cardiovascular disease is one of most frequent cause deaths in modern society. The objective of this work is analyse the effect of dynamic vascular geometry (curvature, torsion, bifurcation) and pulsatile blood nature on secondary flow, wall shear stress and platelet deposition. The problem was examined as multi-scale physical phenomena using perturbation analysis and numerical modelling. T...

Amodel for torsional vibration of slender thin-walled tubes with constrained-layer dampers is developed. Assuming that the deformation obeys the Saint-Venant hypotheses, we develop a model suitable for prediction of the complex stiffness per unit length in closed, thin-walled tubes whose walls consist of laminated elastic and viscoelastic layers, and formulate a boundary-value problem for the w...

In this article an isotropic linear elastic half-space with a cylindrical cavity of finite length is considered to be under the effect of a ring shape time-harmonic torsion force applied at an arbitrary depth on the surface of the cavity. The equation of equilibrium has been written in a cylindrical coordinate system. By means of Fourier cosine integral transform, the non-zero displacement comp...

We examine the effects of thermal fluctuations on thin elastic filaments with non– circular cross–section and arbitrary spontaneous curvature and torsion. Analytical expressions for orientational correlation functions and for the persistence length of helices are derived, and it is found that this length varies non–monotonically with the strength of thermal fluctuations. In the weak fluctuation...