CE 5310 Lecture 3: Topic 3 Lecture notes
Document Summary
Let us consider a wave packet including several wave components. When the wave speeds of individual waves are identical, all the components move in a same rate in space. Also, the shape of the wave packet does not change as it propagate. This means the corresponding wave is not dispersive. Now, let us consider a wave packet that include several wave components having slightly different wave velocities. Some wave components move faster than the other, resulting in a wave packet that changes and stretches the shape as it propagates in space as shown in figure 1. In linear elastic, homogenous and isotropic materials, dispersion occurs depending on the geometry and boundary conditions of a medium. For example, bulk waves propagating in unbounded and isotropic media are not dispersive, and. Lamb waves propagating in traction-free plate-like structures are dispersive. Note that dispersive wave propagation can also occur when the medium is viscous, inhomogeneous and nonlinear, regardless of boundary conditions.
