worldwide networks of seismic recording instruments mostly record only translational ground motion in two or three orthogonal directions. rotational component of earthquake is not commonly recorded. several theories are available to estimate a torsional component from recorded translational components of ground motion. in this paper detailed investigations are made to study the relative perform...

The influence of torsional waves propagating along a thin, vertical, photospheric flux tube on Zeeman-split polarized line profiles (Stokes profiles) is investigated using a simple MHD model. In the presence of such a wave spatially resolved Stokes profiles are found to oscillate strongly in wavelength, amplitude and blue-red asymmetry. Qualitatively, torsional waves induce similar changes into...

The paper studies the possibility of propagation of torsional surface waves in an elastic layer with void pores over an elastic medium with void pores using the mechanics of the medium as derived by Cowin and Nunziato. The velocity equation has been derived and the results have been discussed. The study reveals that there may be more than one torsional surface wave fronts and one Love wave fron...

We present a dynamically tunable mechanism of wave transmission in 1D helicoidal phononic crystals in a shape similar to DNA structures. These helicoidal architectures allow slanted nonlinear contact among cylindrical constituents, and the relative torsional movements can dynamically tune the contact stiffness between neighboring cylinders. This results in cross-talking between in-plane torsion...

High-power Fabry-Perot cavities with suspended mirrors are employed in gravitational wave detection. The mirrors in such interferometers are subject to forces and torques that are exerted by light pressure. This article derives a closed-form expression for the static torsional stiffness due to this effect. The torsional stiffness is shown to scale as the fourth power of the beam spot size. In p...

We present a dynamically tunable mechanism of wave transmission in one-dimensional helicoidal phononic crystals in a shape similar to DNA structures. These helicoidal architectures allow slanted nonlinear contact among cylindrical constituents, and the relative torsional movements can dynamically tune the contact stiffness between neighboring cylinders. This results in cross-talking between in-...

Torsional harmonic cantilevers allow measurement of time-varying tip-sample forces in tapping-mode atomic force microscopy. Accuracy of these force measurements is important for quantitative nanomechanical measurements. Here we demonstrate a method to convert the torsional deflection signals into a calibrated force wave form with the use of nonlinear dynamical response of the tapping cantilever...

The dispersion of torsional wave in transverse and layered one-dimensional component of infinite length is investigated. The study is carried out by treating the one-dimensional component as a cylinder of infinite length firstly, Then put forward a way that the component is divided into a multilayer to analyze torsional wave propagation, the model is constructed in cylindrical coordinates for h...

Laboratory experiments on wave propagation through saturated and partially saturated porous media have often been conducted on porous cylinders that were initially fully saturated and then allowed to dry while continuing to acquire data on the wave behavior. Since it is known that drying typically progresses from outside to inside, a sensible physical model of this process is concentric cylinde...

A novel torsional wave sensor designed to characterize mechanical properties of soft tissues is presented in this work. Elastography is a widely used technique since the 1990s to map tissue stiffness. Moreover, quantitative elastography uses the velocity of shear waves to achieve the shear stiffness. This technique exhibits significant limitations caused by the difficulty of the separation betw...