Info

Figure 2.16 Shapes of Various Wave Types

(a) Quasi-longitudinal wave ftransverse displacements exaggerated,)

(a) Quasi-longitudinal wave ftransverse displacements exaggerated,)

(b) Transverse shear wave

(b) Transverse shear wave

(c) Flexural (bending,) wave

(c) Flexural (bending,) wave

(d) Torsional wave

(d) Torsional wave

Waves in Other Materials

Sound waves in gasses are only longitudinal, since a gas does not support shear or bending. Solid materials, which are bound tightly together, can support more types of wave motion than can a gas or liquid, including shear, torsion, bending, and Rayleigh waves. Figure 2.16 illustrates these various types of wave motion and Table 2.3 lists the formulas for their velocities of propagation. In a later chapter we will discuss some of the effects of flexural (bending) and shear-wave motions in solid plates. Rayleigh waves are a combination of compression and shear waves, which are formed on the surface of solids. They are most commonly encountered in earthquakes when a compression wave, produced at the center of a fault, propagates to the earth's surface and then travels along the surface of the ground as a Rayleigh wave.

0 0

Post a comment