shear wave

shear wave

      transverse wave that occurs in an elastic (elasticity) medium when it is subjected to periodic shear. Shear is the change of shape, without change of volume, of a layer of the substance, produced by a pair of equal forces acting in opposite directions along the two faces of the layer. If the medium is elastic, the layer will resume its original shape after shear, adjacent layers will undergo shear, and the shifting will be propagated as a wave. The velocity (ν) of a shear wave is equal to the square root of the ratio of shear modulus (G), a constant of the medium, to density (ρ) of the medium, ν = √G/ρ.

      Both shear (transverse) and compressional (longitudinal) waves (longitudinal wave) are transmitted in bulk matter. Shear waves travel at about half the speed of compressional waves (e.g., in iron, 3,200 metres per second compared to 5,200 metres per second). Shear waves must be small compared to the cross-sectional area of the medium, and hence narrow rods and bars cannot support shear waves because the transverse motion in them is too large. The shear-wave velocity in a crystal varies according to the direction of propagation and the plane of polarization (i.e., plane of vibration) because of the variation of shear modulus in a crystal.

* * *

Universalium. 2010.

Look at other dictionaries:

  • shear wave — noun : a wave in which the propagated disturbance is a shear strain in an elastic medium * * * shear wave, a wave in an elastic medium which causes movement of the medium but no change in its volume. A secondary wave is a shear wave …   Useful english dictionary

  • shear wave — /ˈʃɪə weɪv/ (say shear wayv) noun an earthquake tremor in which rock particles vibrate at right angles to the direction in which the wave is travelling. Also, secondary wave …   Australian-English dictionary

  • shear wave — noun A wave that changes the medium through which it travels to change its shape but not its volume or density …   Wiktionary

  • Shear modulus — SI symbol: G SI unit: gigapascal Derivations from other quantities: G = τ / γ …   Wikipedia

  • Shear stress — SI symbol: τ SI unit: pascal Derivations from other quantities: τ = F / A …   Wikipedia

  • S-wave — can also refer to the lowest energy electronic wavefunction in atomic physics; see atomic orbital. A type of seismic wave, the S wave, secondary wave, or shear wave, sometimes called an elastic S wave, is one of the two main types of elastic body …   Wikipedia

  • Transverse wave — Transverse plane wave A light wave is an example of a transverse wave …   Wikipedia

  • s wave — noun Usage: usually capitalized S : shear wave * * * Geol. a transverse earthquake wave that travels through the interior of the earth and is usually the second conspicuous wave to reach a seismograph. Also called secondary wave. Cf. L wave, P… …   Useful english dictionary

  • S-wave — noun A transverse, shear wave, such as that produced by an earthquake. Movement is transverse to the direction of propagation and is a body wave Syn: seismic wave …   Wiktionary

  • S wave — noun shear wave …   Wiktionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”