Propagation of the elastic torsional wave
can avoid the dispersion effect in bars, thin-walled tubular specimens can minimize the inertial effect, and no radial displacement between the specimen and the bars can avoid the frictional effect.
In addition, it is necessary to point out that the torsional wave
of the ground motion should be used in (17), but only the horizontal components and the vertical component can be obtained in traditional ground motion database.
Kundu, "Influence of irregularity and rigidity on the propagation of torsional wave
," Applied Mathematical Sciences, vol.
 studied torsional wave
propagation in an earth's crustal layer under the influence of imperfect interface.
Over 100 papers discuss such topics as designing a real-time autofocusing system for a collimator with a long focus length and large aperture, chance constrained model predictive control based on set-valued optimal algorithms, applying virtual prototyping technology in the design of a drive axle, the hydrodynamic forces of torsional wave
propulsion by extended large-amplitude elongated-body theory, the power supply system of embedded portable devices, and numerical analysis in the residual stress test of welded joints for a wind-driven generator.
The wave is composed of 1) a torsional wave
and 2) a longitudinal wave.
Both, low frequency longitudinal wave mode L(0,2)  and torsional wave
mode T(0,1)  have been found to be good candidates for such testing as their wave fields allow to achieve 100% pipe wall inspection coverage and due to non-dispersive nature their wave pulses can propagate long distances.
where C is torsional wave
velocity in the bars, [D.sub.s] is diameter of the bars, [D.sub.s] is mean diameter of the specimen, [L.sub.s] is specimen gauge length, [t.sub.s] is tubular specimen wall thickness, G is shear modulus of the bars, [[gamma].sub.T] is transmitted shear strain pulse, and [[gamma].sub.R] is reflected shear strain pulse.
As the earth's crust and mantle are not homogeneous, it is desirable to have information about torsional wave
propagation in an inhomogeneous medium.
Meehan demonstrated that a baffle filter, comprising a periodic structure of typically 20 m interposed above or below the acoustic sub, can reduce the effects of drill bit noise on modulated torsional wave
 examined Gazis theory and clarified the modes of wave propagation, differentiating certain flexural and torsional wave
Liu, "Torsional wave
in finite length intact pile," Chinese Journal of Applied Mechanics, vol.