Figure 37.

Energy trapping allows to mount resonators at the edge with little damping. When the resonator is thicker in the center than at the edge, the shear vibration is confined to the center. Ideally, the amplitude distribution is smooth (top). Experiments often evidence small-scale variability (bottom, [172,186]). $u^2\left(r\right)$ is the weight function to be applied in area averaging following Equation (26).